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class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> X-Shooting ULLYSES: Massive stars at low metallicity VI. Atmosphere and mass-loss properties of O-type giants in the Small Magellanic Cloud </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Backs%2C+F">Frank Backs</a>, <a href="/search/astro-ph?searchtype=author&query=Brands%2C+S+A">S. A. Brands</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Kaper%2C+L">L. Kaper</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">J. S. Vink</a>, <a href="/search/astro-ph?searchtype=author&query=Puls%2C+J">J. Puls</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J">J. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Tramper%2C+F">F. Tramper</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Bernini-Peron%2C+M">M. Bernini-Peron</a>, <a href="/search/astro-ph?searchtype=author&query=Bestenlehner%2C+J+M">J. M. Bestenlehner</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Kuiper%2C+R">R. Kuiper</a>, <a href="/search/astro-ph?searchtype=author&query=van+Loon%2C+J+T">J. Th. van Loon</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Marcolino%2C+W">W. Marcolino</a>, <a href="/search/astro-ph?searchtype=author&query=Najarro%2C+F">F. Najarro</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Pauli%2C+D">D. Pauli</a>, <a href="/search/astro-ph?searchtype=author&query=Ramachandran%2C+V">V. Ramachandran</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a>, <a href="/search/astro-ph?searchtype=author&query=Verhamme%2C+O">O. Verhamme</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.06884v1-abstract-short" style="display: inline;"> Mass loss through a stellar wind is an important physical process that steers the evolution of massive stars and controls the properties of their end-of-life products, such as the supernova type and the mass of compact remnants. For an accurate mass loss determination, the inhomogeneities in the wind, known as clumping, needs to be taking into account. We aim to improve empirical estimates of mass… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.06884v1-abstract-full').style.display = 'inline'; document.getElementById('2411.06884v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.06884v1-abstract-full" style="display: none;"> Mass loss through a stellar wind is an important physical process that steers the evolution of massive stars and controls the properties of their end-of-life products, such as the supernova type and the mass of compact remnants. For an accurate mass loss determination, the inhomogeneities in the wind, known as clumping, needs to be taking into account. We aim to improve empirical estimates of mass loss and wind clumping for hot main-sequence massive stars, study the dependence of both properties on the metallicity, and compare the theoretical predictions to our findings. We analyzed the optical and UV spectra of 13 O-type stars in the Small Magellanic Cloud galaxy, which has a metallicity of $\sim 0.2\,Z_\odot$. We quantified the stellar atmosphere, outflow, and wind-clumping properties. To probe the role of metallicity, we compared our findings to studies of Galactic and Large Magellanic Cloud samples that were analyzed with similar methods. We find significant variations in the wind-clumping properties of the target stars, with clumping starting at flow velocities $0.01 - 0.23$ of the terminal wind velocity and reaching clumping factors $f_{\rm cl} = 2 - 30$. In the luminosity ($\log L / L_{\odot} = 5.0 - 6.0$) and metallicity ($Z/Z_{\odot} = 0.2 - 1$) range we considered, we find that the scaling of the mass loss $\dot{M}$ with metallicity $Z$ varies with luminosity. At $\log L/L_{\odot} = 5.75$, we find $\dot{M} \propto Z^m$ with $m = 1.02 \pm 0.30$, in agreement with pioneering work in the field. For lower luminosities, however, we obtain a significantly steeper scaling of $m > 2$. The monotonically decreasing $m(L)$ behavior adds a complexity to the functional description of the mass-loss rate of hot massive stars. Although the trend is present in the predictions, it is much weaker than we found here. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.06884v1-abstract-full').style.display = 'none'; document.getElementById('2411.06884v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">37 pages, 29 figures. Accepted for publication in Astronomy and Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.21394">arXiv:2410.21394</a> <span> [<a href="https://arxiv.org/pdf/2410.21394">pdf</a>, <a href="https://arxiv.org/format/2410.21394">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Modeling contact binaries, III. Properties of a population of close, massive binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">Matthias Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">Norbert Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.21394v2-abstract-short" style="display: inline;"> Among massive stars, binary interaction is the rule rather than the exception. The closest binaries, those with periods of less than about 10 days, undergo mass transfer during core-hydrogen burning, with many of them experiencing a nuclear-timescale contact phase. Current binary population synthesis models predict the mass-ratio distribution of contact binaries to be heavily skewed toward a mass… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.21394v2-abstract-full').style.display = 'inline'; document.getElementById('2410.21394v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.21394v2-abstract-full" style="display: none;"> Among massive stars, binary interaction is the rule rather than the exception. The closest binaries, those with periods of less than about 10 days, undergo mass transfer during core-hydrogen burning, with many of them experiencing a nuclear-timescale contact phase. Current binary population synthesis models predict the mass-ratio distribution of contact binaries to be heavily skewed toward a mass ratio of unity, which is inconsistent with observations. It has been shown that effects of tidal deformation due to the Roche potential, as well as energy transfer in the common layers of a contact binary, alter the internal structure of close binary components. However, previous population studies neglected these effects. We model a population of massive binary stars that undergo mass transfer during core-hydrogen burning, while consistently considering the effects of tidal deformation and energy transfer in contact phases. We use the MESA binary-evolution code to compute large grids of models with primary star masses of $8\,M_\odot$ to $70\,M_\odot$ at Solar metallicity. We then perform a population synthesis study to predict distribution functions of the observational properties of close binary systems, focusing in particular on the mass and luminosity ratio distribution. We find that the effects of tidal deformation and energy transfer have a limited effect on the predicted mass-ratio distribution of massive contact binaries. Only a small fraction of the population has their mass ratio significantly shifted toward a more unequal configuration. However, we suggest that orbital hardening could affect the evolution of contact binaries and their progenitors, and we advocate for a homogeneous set of observed contact binary parameters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.21394v2-abstract-full').style.display = 'none'; document.getElementById('2410.21394v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 10 Figures, (22 pages, 16 Figs. including appendices). Submitted to A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.14937">arXiv:2410.14937</a> <span> [<a href="https://arxiv.org/pdf/2410.14937">pdf</a>, <a href="https://arxiv.org/format/2410.14937">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202451169">10.1051/0004-6361/202451169 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-Shooting ULLYSES: Massive Stars at low metallicity IX: Empirical constraints on mass-loss rates and clumping parameters for OB supergiants in the Large Magellanic Cloud </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Verhamme%2C+O">O. Verhamme</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J">J. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Backs%2C+F">F. Backs</a>, <a href="/search/astro-ph?searchtype=author&query=Brands%2C+S+A">S. A. Brands</a>, <a href="/search/astro-ph?searchtype=author&query=Najarro%2C+F">F. Najarro</a>, <a href="/search/astro-ph?searchtype=author&query=Puls%2C+J">J. Puls</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">J. S. Vink</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Kub%C3%A1tov%C3%A1%2C+B">B. Kub谩tov谩</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a>, <a href="/search/astro-ph?searchtype=author&query=Bernini-Peron%2C+M">M. Bernini-Peron</a>, <a href="/search/astro-ph?searchtype=author&query=Kuiper%2C+R">R. Kuiper</a>, <a href="/search/astro-ph?searchtype=author&query=Prinja%2C+R+K">R. K. Prinja</a>, <a href="/search/astro-ph?searchtype=author&query=Schillemans%2C+P">P. Schillemans</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=van+Loon%2C+J+T">J. Th. van Loon</a>, <a href="/search/astro-ph?searchtype=author&query=collaboration%2C+X">XShootu collaboration</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.14937v2-abstract-short" style="display: inline;"> Context. Current implementations of mass loss for hot, massive stars in stellar evolution models include a sharp increase in mass loss when blue supergiants become cooler than Teff 20-22kK. This drastic mass-loss jump has been motivated by the potential presence of a so-called bistability ionisation effect, which may occur for line-driven winds in this temperature region due to recombination of im… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.14937v2-abstract-full').style.display = 'inline'; document.getElementById('2410.14937v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.14937v2-abstract-full" style="display: none;"> Context. Current implementations of mass loss for hot, massive stars in stellar evolution models include a sharp increase in mass loss when blue supergiants become cooler than Teff 20-22kK. This drastic mass-loss jump has been motivated by the potential presence of a so-called bistability ionisation effect, which may occur for line-driven winds in this temperature region due to recombination of important line-driving ions. Aims. We perform quantitative spectroscopy using UV (ULLYSES program) and optical (XShootU collaboration) data for 17 OB-supergiant stars in the LMC (covering the range Teff 14-32kK), deriving absolute constraints on global stellar, wind, and clumping parameters. We examine whether there are any empirical signs of a mass-loss jump in the investigated region, and we study the clumped nature of the wind. Methods. We use a combination of the model atmosphere code fastwind and the genetic algorithm code Kiwi-GA to fit synthetic spectra of a multitude of diagnostic spectral lines in the optical and UV. Results. We find no signs of any upward mass loss jump anywhere in the examined region. Standard theoretical comparison models, which include a strong bistability jump thus severely over predict the empirical mass-loss rates on the cool side of the predicted jump. Additionally, we find that on average about 40% of the total wind mass seems to reside in the diluted medium in between dense clumps. Conclusions. Our derived mass-loss rates suggest that for applications like stellar evolution one should not include a drastic bistability jump in mass loss for stars in the temperature and luminosity region investigated here. The derived high values of interclump density further suggest that the common assumption of an effectively void interclump medium (applied in the vast majority of spectroscopic studies of hot star winds) is not generally valid in this parameter regime. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.14937v2-abstract-full').style.display = 'none'; document.getElementById('2410.14937v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 692, A91 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.06255">arXiv:2410.06255</a> <span> [<a href="https://arxiv.org/pdf/2410.06255">pdf</a>, <a href="https://arxiv.org/format/2410.06255">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41586-024-08013-8">10.1038/s41586-024-08013-8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Two waves of massive stars running away from the young cluster R136 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Stoop%2C+M">Mitchel Stoop</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">Alex de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Kaper%2C+L">Lex Kaper</a>, <a href="/search/astro-ph?searchtype=author&query=Brands%2C+S">Sarah Brands</a>, <a href="/search/astro-ph?searchtype=author&query=Zwart%2C+S+P">Simon Portegies Zwart</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Stoppa%2C+F">Fiorenzo Stoppa</a>, <a href="/search/astro-ph?searchtype=author&query=Gieles%2C+M">Mark Gieles</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">Tomer Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+D">Difeng Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Nelemans%2C+G">Gijs Nelemans</a>, <a href="/search/astro-ph?searchtype=author&query=Rieder%2C+S">Steven Rieder</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.06255v1-abstract-short" style="display: inline;"> Massive stars are predominantly born in stellar associations or clusters. Their radiation fields, stellar winds, and supernovae strongly impact their local environment. In the first few million years of a cluster's life, massive stars are dynamically ejected running away from the cluster at high speed. However, the production rate of dynamically ejected runaways is poorly constrained. Here we repo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.06255v1-abstract-full').style.display = 'inline'; document.getElementById('2410.06255v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.06255v1-abstract-full" style="display: none;"> Massive stars are predominantly born in stellar associations or clusters. Their radiation fields, stellar winds, and supernovae strongly impact their local environment. In the first few million years of a cluster's life, massive stars are dynamically ejected running away from the cluster at high speed. However, the production rate of dynamically ejected runaways is poorly constrained. Here we report on a sample of 55 massive runaway stars ejected from the young cluster R136 in the Large Magellanic Cloud. Astrometric analysis with Gaia reveals two channels of dynamically ejected runaways. The first channel ejects massive stars in all directions and is consistent with dynamical interactions during and after the birth of R136. The second channel launches stars in a preferred direction and may be related to a cluster interaction. We find that 23-33% of the most luminous stars initially born in R136 are runaways. Model predictions have significantly underestimated the dynamical escape fraction of massive stars. Consequently, their role in shaping and heating the interstellar and galactic medium, along with their role in driving galactic outflows, is far more important than previously thought. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.06255v1-abstract-full').style.display = 'none'; document.getElementById('2410.06255v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in Nature on 2024 October 09. 39 pages, 17 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.16212">arXiv:2409.16212</a> <span> [<a href="https://arxiv.org/pdf/2409.16212">pdf</a>, <a href="https://arxiv.org/format/2409.16212">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/ad6f06">10.3847/1538-3881/ad6f06 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Low-mass stellar and substellar candidate companions around massive stars in Sco OB1 and M17 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pauwels%2C+T">Tinne Pauwels</a>, <a href="/search/astro-ph?searchtype=author&query=Reggiani%2C+M">Maddalena Reggiani</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.16212v1-abstract-short" style="display: inline;"> Massive stars are recognized for their high degree of multiplicity, yet the mass ratio regime below 0.1 remains insufficiently explored. It is therefore unknown whether extremely low-mass (possibly substellar) companions can form and survive in the direct UV-irradiated environment of massive stars. In this paper, we discuss VLT/SPHERE IFS (0".15 - 0".85) observations of six massive O- and early B-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.16212v1-abstract-full').style.display = 'inline'; document.getElementById('2409.16212v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.16212v1-abstract-full" style="display: none;"> Massive stars are recognized for their high degree of multiplicity, yet the mass ratio regime below 0.1 remains insufficiently explored. It is therefore unknown whether extremely low-mass (possibly substellar) companions can form and survive in the direct UV-irradiated environment of massive stars. In this paper, we discuss VLT/SPHERE IFS (0".15 - 0".85) observations of six massive O- and early B-type stars in Sco OB1 and M17 that each have a low-mass candidate companion. Two targets have companions that are brown dwarf candidates. The other four have candidate companions in the low end of the stellar mass regime ($\leq$ 0.30 M$_\odot$). For three of these, we have obtained a second epoch observation. At least two sources exhibit similar proper motion to that of their central star. However, given the expected proper motion of background objects, this does not imply certain companionship. We show how future follow-up observations of the brown dwarf candidate companions in $J$, $H$ and $L$ bands should allow for an unambiguous confirmation of their nature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.16212v1-abstract-full').style.display = 'none'; document.getElementById('2409.16212v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 6 figures, accepted for publication in AJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.15212">arXiv:2409.15212</a> <span> [<a href="https://arxiv.org/pdf/2409.15212">pdf</a>, <a href="https://arxiv.org/format/2409.15212">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Investigating 39 Galactic Wolf-Rayet stars with VLTI/GRAVITY: Uncovering A Long Period Binary Desert </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+K">K. Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%A9rand%2C+A">A. M茅rand</a>, <a href="/search/astro-ph?searchtype=author&query=Bordier%2C+E">E. Bordier</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">A. J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Gosset%2C+E">E. Gosset</a>, <a href="/search/astro-ph?searchtype=author&query=Bouquin%2C+J+-+L">J. -B. Le Bouquin</a>, <a href="/search/astro-ph?searchtype=author&query=Lefever%2C+R+R">R. R. Lefever</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Patrick%2C+L+R">L. R. Patrick</a>, <a href="/search/astro-ph?searchtype=author&query=Reggiani%2C+M">M. Reggiani</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Tramper%2C+F">F. Tramper</a>, <a href="/search/astro-ph?searchtype=author&query=Villase%C3%B1or%2C+J+I">J. I. Villase帽or</a>, <a href="/search/astro-ph?searchtype=author&query=Waisberg%2C+I">I. Waisberg</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.15212v2-abstract-short" style="display: inline;"> Wolf-Rayet stars (WRs) are one of the final evolutionary stages of massive stars and immediate progenitors of stellar-mass black holes. Their multiplicity forms an important anchor point in single and binary population models for predicting gravitational-wave progenitors. Recent spectroscopic campaigns have suggested incompatible multiplicity fractions and period distributions for N- and C-rich Ga… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15212v2-abstract-full').style.display = 'inline'; document.getElementById('2409.15212v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.15212v2-abstract-full" style="display: none;"> Wolf-Rayet stars (WRs) are one of the final evolutionary stages of massive stars and immediate progenitors of stellar-mass black holes. Their multiplicity forms an important anchor point in single and binary population models for predicting gravitational-wave progenitors. Recent spectroscopic campaigns have suggested incompatible multiplicity fractions and period distributions for N- and C-rich Galactic WRs (WNs and WCs) at short as well as long orbital periods, in contradiction with evolutionary model predictions. In this work, we employed infrared interferometry using the $K$-band instrument GRAVITY at the VLTI to investigate the multiplicity of WRs at long periods and explore the nature of their companions. We present a survey of 39 Galactic WRs, including 11 WN, 15 WC and 13 H-rich WN (WNh) stars. We detected wide companions with GRAVITY for only four stars: WR 48, WR 89, WR 93 and WR 115. Combining with spectroscopic studies, we arrived at multiplicity fractions of $f^{\rm WN}_{\rm obs} = 0.55\pm0.15$, $f^{\rm WC}_{\rm obs} = 0.40\pm0.13$ and $f^{\rm WNh}_{\rm obs} = 0.23\pm0.12$. In addition, we also found other features in the GRAVITY dataset such as (i) a diffuse extended component in over half the WR sample; (ii) five known spectroscopic binaries resolved in differential phase data and (iii) spatially resolved winds in four stars: WR 16, WR 31a, WR 78 and WR 110. Our survey reveals a lack of intermediate (few 100s d) and long- (few years to decades) period WR systems. The 200-d peak in the period distributions of WR+OB and BH+OB binaries predicted by Case B mass-transfer binary evolution models is not seen in our data. The rich companionship of their O-type progenitors in this separation range suggest that the WR progenitor stars expand and interact with their companions, most likely through unstable mass-transfer, resulting in either a short-period system or a merger. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15212v2-abstract-full').style.display = 'none'; document.getElementById('2409.15212v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.08116">arXiv:2408.08116</a> <span> [<a href="https://arxiv.org/pdf/2408.08116">pdf</a>, <a href="https://arxiv.org/format/2408.08116">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202450256">10.1051/0004-6361/202450256 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The spectroscopic binary fraction of the young stellar cluster M17 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ram%C3%ADrez-Tannus%2C+M+C">M. C. Ram铆rez-Tannus</a>, <a href="/search/astro-ph?searchtype=author&query=Derkink%2C+A+R">A. R. Derkink</a>, <a href="/search/astro-ph?searchtype=author&query=Backs%2C+F">F. Backs</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Poorta%2C+J">J. Poorta</a>, <a href="/search/astro-ph?searchtype=author&query=Kaper%2C+L">L. Kaper</a>, <a href="/search/astro-ph?searchtype=author&query=Stoop%2C+M">M. Stoop</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.08116v1-abstract-short" style="display: inline;"> Significant progress has been made toward understanding the formation of massive ($M > 8~$M$_{\odot}$) binaries in close orbits. For example, the detection of a very low velocity dispersion among the massive stars in the young region M17 and the measurement of a positive trend of velocity dispersion with age in Galactic clusters. The velocity dispersion observed in M17 could be explained either by… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.08116v1-abstract-full').style.display = 'inline'; document.getElementById('2408.08116v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.08116v1-abstract-full" style="display: none;"> Significant progress has been made toward understanding the formation of massive ($M > 8~$M$_{\odot}$) binaries in close orbits. For example, the detection of a very low velocity dispersion among the massive stars in the young region M17 and the measurement of a positive trend of velocity dispersion with age in Galactic clusters. The velocity dispersion observed in M17 could be explained either by the lack of binaries among the stars in this region or by larger binary separations than typically observed, but with a binary fraction similar to other young Galactic clusters. The latter implies that over time, the binary components migrate toward each other. We aim to determine the origin of the strikingly low velocity dispersion by determining the observed and intrinsic binary fraction of massive stars in M17 through multi-epoch spectroscopy. We performed a multi-epoch spectroscopic survey consisting of three epochs separated by days and months. We determine the radial velocity of each star at each epoch by fitting the stellar absorption profiles. We determine an observed binary fraction of 27% and an intrinsic binary fraction of 87%, consistent with that of other Galactic clusters. We conclude that the low velocity dispersion is due to a large separation among the young massive binaries in M17. Our result is in agreement with a migration scenario in which massive stars are born in binaries or higher order systems at large separation and harden within the first million years of evolution. Such an inward migration may either be driven by interaction with a remnant accretion disk, with other young stellar objects present in the system or by dynamical interactions within the cluster. Our results imply that possibly both dynamical interactions and binary evolution are key processes in the formation of gravitational wave sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.08116v1-abstract-full').style.display = 'none'; document.getElementById('2408.08116v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in A&A. 18 pages, 8 figures. Appendices A and C will be available in electronic form at the CDS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 690, A178 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.14593">arXiv:2407.14593</a> <span> [<a href="https://arxiv.org/pdf/2407.14593">pdf</a>, <a href="https://arxiv.org/format/2407.14593">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202451586">10.1051/0004-6361/202451586 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Binarity at LOw Metallicity (BLOeM): a spectroscopic VLT monitoring survey of massive stars in the SMC </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Lennon%2C+D+J">D. J. Lennon</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Almeida%2C+L+A">L. A. Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Backs%2C+F">F. Backs</a>, <a href="/search/astro-ph?searchtype=author&query=Berlanas%2C+S+R">S. R. Berlanas</a>, <a href="/search/astro-ph?searchtype=author&query=Bernini-Peron%2C+M">M. Bernini-Peron</a>, <a href="/search/astro-ph?searchtype=author&query=Bestenlehner%2C+J+M">J. M. Bestenlehner</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Bronner%2C+V+A">V. A. Bronner</a>, <a href="/search/astro-ph?searchtype=author&query=Britavskiy%2C+N">N. Britavskiy</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=de+Mink%2C+S+E">S. E. de Mink</a>, <a href="/search/astro-ph?searchtype=author&query=Deshmukh%2C+K">K. Deshmukh</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+C+J">C. J. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">M. Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Gieles%2C+M">M. Gieles</a>, <a href="/search/astro-ph?searchtype=author&query=Gilkis%2C+A">A. Gilkis</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Tor%C3%A0%2C+G">G. Gonz谩lez-Tor脿</a>, <a href="/search/astro-ph?searchtype=author&query=Gr%C3%A4fener%2C+G">G. Gr盲fener</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B6tberg%2C+Y">Y. G枚tberg</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a> , et al. (52 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.14593v2-abstract-short" style="display: inline;"> Surveys in the Milky Way and Large Magellanic Cloud revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary properties of massive stars at low metallicity, which approaches the conditions of the Early Universe, remains sparse. We present the Binarity at LOw Metallicity (BLOeM) campaign - an ESO large programme designed to obtai… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.14593v2-abstract-full').style.display = 'inline'; document.getElementById('2407.14593v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.14593v2-abstract-full" style="display: none;"> Surveys in the Milky Way and Large Magellanic Cloud revealed that the majority of massive stars will interact with companions during their lives. However, knowledge of the binary properties of massive stars at low metallicity, which approaches the conditions of the Early Universe, remains sparse. We present the Binarity at LOw Metallicity (BLOeM) campaign - an ESO large programme designed to obtain 25 epochs of spectroscopy for 929 massive stars in the SMC - the lowest metallicity conditions in which multiplicity is probed to date (Z = 0.2 Zsun). BLOeM will provide (i) the binary fraction, (ii) the orbital configurations of systems with periods P < 3 yr, (iii) dormant OB+BH binaries, and (iv) a legacy database of physical parameters of massive stars at low metallicity. The stars are observed with the LR02 setup of the giraffe instrument of the Very Large Telescope (3960-4570A, resolving power R=6200; typical signal-to-noise ratio S/N=70-100). This paper utilises the first 9 epochs obtained over a three-month time. We describe the survey and data reduction, perform a spectral classification of the stacked spectra, and construct a Hertzsprung-Russell diagram of the sample via spectral-type and photometric calibrations. The sample covers spectral types from O4 to F5, spanning the effective temperature and luminosity ranges 6.5<Teff/kK<45 and 3.7<log L/Lsun<6.1 and initial masses 8<Mini/Msun<80. It comprises 159 O-type stars, 331 early B-type (B0-3) dwarfs and giants (luminosity classes V-III), 303 early B-type supergiants (II-I), and 136 late-type supergiants. At least 82 stars are Oe/Be stars: 20 O-type and 62 B-type (13% and 11% of the respective samples). In addition, it includes 4 high-mass X-ray binaries, 3 stars resembling luminous blue variables, 2 bloated stripped-star candidates, 2 candidate magnetic stars, and 74 eclipsing binaries. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.14593v2-abstract-full').style.display = 'none'; document.getElementById('2407.14593v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to A&A on 27 Aug 2024</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 690, A289 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.06775">arXiv:2407.06775</a> <span> [<a href="https://arxiv.org/pdf/2407.06775">pdf</a>, <a href="https://arxiv.org/format/2407.06775">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202348478">10.1051/0004-6361/202348478 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Empirical mass-loss rates and clumping properties of O-type stars in the LMC </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J+O">J. O. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Brands%2C+S+A">S. A. Brands</a>, <a href="/search/astro-ph?searchtype=author&query=Decin%2C+L">L. Decin</a>, <a href="/search/astro-ph?searchtype=author&query=deKoter%2C+A">A. deKoter</a>, <a href="/search/astro-ph?searchtype=author&query=Puls%2C+J">J. Puls</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.06775v1-abstract-short" style="display: inline;"> We constrain wind parameters of a sample of 18 O-type stars in the LMC, through analysis with stellar atmosphere and wind models including the effects of optically thick clumping. This allows us to determine the most accurate spectroscopic mass-loss and wind structure properties of massive stars at sub-solar metallicity to date and gain insight into the impact of metallicity on massive stellar win… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.06775v1-abstract-full').style.display = 'inline'; document.getElementById('2407.06775v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.06775v1-abstract-full" style="display: none;"> We constrain wind parameters of a sample of 18 O-type stars in the LMC, through analysis with stellar atmosphere and wind models including the effects of optically thick clumping. This allows us to determine the most accurate spectroscopic mass-loss and wind structure properties of massive stars at sub-solar metallicity to date and gain insight into the impact of metallicity on massive stellar winds. Combining high signal to noise (S/N) ratio spectroscopy in the UV and optical gives us access to diagnostics of multiple different physical processes in the stellar wind. We produce synthetic spectra using the stellar atmosphere modelling code FASTWIND, and reproduce the observed spectra using a genetic algorithm based fitting technique. We empirically constrain 15 physical parameters associated with the stellar and wind properties, including temperature, surface gravity, surface abundances, rotation, macroturbulence and wind parameters. We find, on average, mass-loss rates a factor of 4-5 lower than those predicted by Vink et al. 2001, in good agreement with predictions from Bjorklund et al. 2021, and the best agreement with those from Krticka et al. 2018. In the 'weak-wind' regime we find mass-loss rates orders of magnitude below any theoretical predictions. We find a positive correlation of clumping factors (fcl) with effective temperature with an average fcl = 14 +- 8 for the full sample. Above 38 kK an average 46 +- 24% of the wind velocity span is covered by clumps and the interclump density is 10-30% of the mean wind. Below an effective temperature of roughly 38 kK there must be additional light leakage for supergiants. For dwarf stars at low temperatures there is a statistical preference for very low clump velocity spans, however it is unclear if this can be physically motivated as there are no clearly observable wind signatures in UV diagnostics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.06775v1-abstract-full').style.display = 'none'; document.getElementById('2407.06775v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages with 6 figures, plus 16 pages and 18 figures in appendix. Accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 690, A126 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.01420">arXiv:2406.01420</a> <span> [<a href="https://arxiv.org/pdf/2406.01420">pdf</a>, <a href="https://arxiv.org/format/2406.01420">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202449978">10.1051/0004-6361/202449978 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An absence of binary companions to Wolf-Rayet stars in the Small Magellanic Cloud: implications for mass loss and black hole masses at low metallicity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Schootemeijer%2C+A">A. Schootemeijer</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Grin%2C+N">N. Grin</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Sch%C3%BCrmann%2C+G+G+C">G. Gr盲fener C. Sch眉rmann</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+C">C. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+X+-">X. -T. Xu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.01420v1-abstract-short" style="display: inline;"> In order to predict the black hole mass distributions at high redshift, we need to understand whether very massive single stars ($M>40$ M$_\odot$) at low metallicity $Z$ lose their hydrogen-rich envelopes, like their metal-rich counterparts, or whether a binary companion is required to achieve this. To test this, we undertake a deep spectroscopic search for binary companions of the seven apparentl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.01420v1-abstract-full').style.display = 'inline'; document.getElementById('2406.01420v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.01420v1-abstract-full" style="display: none;"> In order to predict the black hole mass distributions at high redshift, we need to understand whether very massive single stars ($M>40$ M$_\odot$) at low metallicity $Z$ lose their hydrogen-rich envelopes, like their metal-rich counterparts, or whether a binary companion is required to achieve this. To test this, we undertake a deep spectroscopic search for binary companions of the seven apparently single Wolf-Rayet (WR) stars in the Small Magellanic Cloud (SMC; $Z \simeq 1/5 Z_\odot$). For each of them, we acquired six high-quality VLT-UVES spectra spread over 1.5 years. By using the narrow N V lines in these spectra, we monitor radial velocity (RV) variations to search for binary motion. We find low RV variations between 6 and 23 km/s for the seven WR stars, with a median standard deviation of $5$ km/s. Our Monte Carlo simulations imply probabilities below ~5% for any of our target WR stars to have a binary companion more massive than ~5 M$_\odot$ at orbital periods of less than a year. We estimate that the probability that all our target WR stars have companions with orbital periods shorter than 10 yr is below ~10$^{-5}$, and argue that the observed modest RV variations may originate from intrinsic atmosphere or wind variability. Our findings imply that metal-poor massive stars born with $M \gtrsim 40$ M$_\odot$ can lose most of their hydrogen-rich envelopes via stellar winds or eruptive mass loss, which strongly constrains their initial mass - black hole mass relation. We also identify two of our seven target stars (SMC AB1 and SMC AB11) as runaway stars with a peculiar radial velocity of ~80 km/s. Moreover, with all five previously detected WR binaries in the SMC exhibiting orbital periods of below 20 d, a puzzling absence of intermediate-to-long-period WR binaries has emerged, with strong implications for the outcome of massive binary interaction at low metallicity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.01420v1-abstract-full').style.display = 'none'; document.getElementById('2406.01420v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 689, A157 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.17608">arXiv:2405.17608</a> <span> [<a href="https://arxiv.org/pdf/2405.17608">pdf</a>, <a href="https://arxiv.org/format/2405.17608">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202450583">10.1051/0004-6361/202450583 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Rotational synchronisation of B-type binaries in 30 Doradus </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lennon%2C+D+J">D. J. Lennon</a>, <a href="/search/astro-ph?searchtype=author&query=Dufton%2C+P+L">P. L. Dufton</a>, <a href="/search/astro-ph?searchtype=author&query=Villase%C3%B1or%2C+J+I">J. I. Villase帽or</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+C+J">C. J. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Taylor%2C+W+D">W. D. Taylor</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.17608v1-abstract-short" style="display: inline;"> The spin evolution of stars in close binary systems can be strongly affected by tides. We investigate the rotational synchronisation of the stellar components for 69 SB1 systems and 14 SB2 B-type systems in the 30 Doradus region of the Large Magellanic Cloud using observations from the VFTS and BBC surveys. Their orbital periods range from a few to a few hundred days, while estimated primary masse… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.17608v1-abstract-full').style.display = 'inline'; document.getElementById('2405.17608v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.17608v1-abstract-full" style="display: none;"> The spin evolution of stars in close binary systems can be strongly affected by tides. We investigate the rotational synchronisation of the stellar components for 69 SB1 systems and 14 SB2 B-type systems in the 30 Doradus region of the Large Magellanic Cloud using observations from the VFTS and BBC surveys. Their orbital periods range from a few to a few hundred days, while estimated primary masses for these systems are in the range 5-20 Msun with mass ratio ranges of approximately q=0.03-0.5 and q=0.6-1.0 for the SB1 and SB2 systems, respectively. Projected rotational velocities of the stellar components have been compared with their synchronous velocities derived from the orbital periods. We find that effectively all systems with orbital period of more than 10 days must be asynchronous, whilst all the systems with periods of less than 3 days are likely synchronised. In terms of the stellar fractional radius (r), our results imply that all systems with r<0.1 are asynchronous, with those having r>0.2 probably being synchronised. For the apparently synchronised systems our results are more consistent with synchronisation at the mean orbital angular velocity rather than with that at periastron. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.17608v1-abstract-full').style.display = 'none'; document.getElementById('2405.17608v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 5 figures. submitted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 688, A141 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.00085">arXiv:2405.00085</a> <span> [<a href="https://arxiv.org/pdf/2405.00085">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> X-Shooting ULLYSES: Massive Stars at Low Metallicity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">Jorick S. Vink</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P">Paul Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Fullerton%2C+A">Alex Fullerton</a>, <a href="/search/astro-ph?searchtype=author&query=Garcia%2C+M">Miriam Garcia</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+F">Fabrice Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">Nidia Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">Lida Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Louis%2C+N+S">Nicole St. Louis</a>, <a href="/search/astro-ph?searchtype=author&query=ud-Doula%2C+A">Asif ud-Doula</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A">Andreas Sander</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Bouret%2C+J">Jean-Claude Bouret</a>, <a href="/search/astro-ph?searchtype=author&query=Kubatova%2C+B">Brankica Kubatova</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+L+P">Lucimara P. Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Wofford%2C+A">Aida Wofford</a>, <a href="/search/astro-ph?searchtype=author&query=van+Loon%2C+J">Jacco van Loon</a>, <a href="/search/astro-ph?searchtype=author&query=Telford%2C+O+G">O. Grace Telford</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B6tberg%2C+Y">Ylva G枚tberg</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D">Dominic Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Erba%2C+C">Christi Erba</a>, <a href="/search/astro-ph?searchtype=author&query=Kalari%2C+V">Venu Kalari</a>, <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+T+X">The XShootU Collaboration</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.00085v1-abstract-short" style="display: inline;"> The Hubble Space Telescope has devoted 500 orbits to observing 250 massive stars with low metallicity in the ultraviolet (UV) range within the framework of the ULLYSES program. The X-Shooting ULLYSES (XShootU) project enhances the legacy value of this UV dataset by providing high-quality optical and near-infrared spectra, which are acquired using the wide-wavelength-coverage X-shooter spectrograph… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.00085v1-abstract-full').style.display = 'inline'; document.getElementById('2405.00085v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.00085v1-abstract-full" style="display: none;"> The Hubble Space Telescope has devoted 500 orbits to observing 250 massive stars with low metallicity in the ultraviolet (UV) range within the framework of the ULLYSES program. The X-Shooting ULLYSES (XShootU) project enhances the legacy value of this UV dataset by providing high-quality optical and near-infrared spectra, which are acquired using the wide-wavelength-coverage X-shooter spectrograph at ESO's Very Large Telescope. XShootU emphasises the importance of combining UV with optical spectra for the consistent determination of key stellar parameters such as effective temperature, surface gravity, luminosity, abundances, and wind characteristics including mass-loss rates as a function of metallicity. Since uncertainties in these parameters have implications across various branches of astrophysics, the data and modelling generated by the XShootU project are poised to significantly advance our understanding of massive stars at low metallicity. This is particularly crucial for confidently interpreting JWST data of the earliest stellar generations, making XShootU a unique resource for comprehending individual spectra of low-metallicity stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.00085v1-abstract-full').style.display = 'none'; document.getElementById('2405.00085v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 6 figures. ESO Large Programme Overview</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ESO Messenger, 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.10167">arXiv:2404.10167</a> <span> [<a href="https://arxiv.org/pdf/2404.10167">pdf</a>, <a href="https://arxiv.org/format/2404.10167">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1126/science.adg7700">10.1126/science.adg7700 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A magnetic massive star has experienced a stellar merger </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">A. J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Wade%2C+G">G. Wade</a>, <a href="/search/astro-ph?searchtype=author&query=Barron%2C+J">J. Barron</a>, <a href="/search/astro-ph?searchtype=author&query=Bouquin%2C+J+-+L">J. -B. Le Bouquin</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%A9rand%2C+A">A. M茅rand</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+F+R+N">F. R. N. Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Barb%C3%A1%2C+R+H">R. H. Barb谩</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">M. Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Farhang%2C+A">A. Farhang</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N+I">N. I. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Smoker%2C+J+V">J. V. Smoker</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.10167v1-abstract-short" style="display: inline;"> Massive stars (those larger than 8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7\% of massive stars have observed magnetic fields, the origin of which is debated. We used multi-epoch interferometric and spectroscopic observations to characterize HD 148937, a binary sys… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10167v1-abstract-full').style.display = 'inline'; document.getElementById('2404.10167v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.10167v1-abstract-full" style="display: none;"> Massive stars (those larger than 8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7\% of massive stars have observed magnetic fields, the origin of which is debated. We used multi-epoch interferometric and spectroscopic observations to characterize HD 148937, a binary system of two massive stars. We found that only one star is magnetic and that it appears younger than its companion. The system properties and a surrounding bipolar nebula can be reproduced with a model in which two stars merged (in a previous triple system) to produce the magnetic massive star. Our results provide observational evidence that magnetic fields form in at least some massive stars through stellar mergers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10167v1-abstract-full').style.display = 'none'; document.getElementById('2404.10167v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Full paper with supplementary materials. 59 pages, 18 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science, 11 Apr 2024, Vol 384, Issue 6692, pp. 214-217 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.16987">arXiv:2402.16987</a> <span> [<a href="https://arxiv.org/pdf/2402.16987">pdf</a>, <a href="https://arxiv.org/format/2402.16987">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202347479">10.1051/0004-6361/202347479 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-Shooting ULLYSES: Massive Stars at low metallicity II. DR1: Advanced optical data products for the Magellanic Clouds </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Tramper%2C+F">F. Tramper</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Blomme%2C+R">R. Blomme</a>, <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Maravelias%2C+G">G. Maravelias</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+L">L. Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Mehner%2C+A">A. Mehner</a>, <a href="/search/astro-ph?searchtype=author&query=Wofford%2C+A">A. Wofford</a>, <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">G. Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Barbosa%2C+C+L">C. L. Barbosa</a>, <a href="/search/astro-ph?searchtype=author&query=Bestenlehner%2C+J">J. Bestenlehner</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Hillier%2C+D+J">D. John Hillier</a>, <a href="/search/astro-ph?searchtype=author&query=Todt%2C+H">H. Todt</a>, <a href="/search/astro-ph?searchtype=author&query=Larkin%2C+C+J+K">C. J. K. Larkin</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Najarro%2C+F">F. Najarro</a>, <a href="/search/astro-ph?searchtype=author&query=Ramachandran%2C+V">V. Ramachandran</a>, <a href="/search/astro-ph?searchtype=author&query=Ramirez-Tannus%2C+M+C">M. C. Ramirez-Tannus</a>, <a href="/search/astro-ph?searchtype=author&query=Rubio-Diez%2C+M+M">M. M. Rubio-Diez</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">J. S. Vink</a>, <a href="/search/astro-ph?searchtype=author&query=Backs%2C+F">F. Backs</a> , et al. (12 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.16987v1-abstract-short" style="display: inline;"> Using the medium resolution spectrograph X-shooter, spectra of 235 OB and Wolf-Rayet (WR) stars in sub-solar metallicity environments have been secured. [...]This second paper focuses on the optical observations of 232 Magellanic Clouds targets. It describes the uniform reduction of the UVB (300 - 560 nm) and VIS (550 - 1020 nm) XShootU data as well as the preparation of advanced data products [..… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.16987v1-abstract-full').style.display = 'inline'; document.getElementById('2402.16987v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.16987v1-abstract-full" style="display: none;"> Using the medium resolution spectrograph X-shooter, spectra of 235 OB and Wolf-Rayet (WR) stars in sub-solar metallicity environments have been secured. [...]This second paper focuses on the optical observations of 232 Magellanic Clouds targets. It describes the uniform reduction of the UVB (300 - 560 nm) and VIS (550 - 1020 nm) XShootU data as well as the preparation of advanced data products [...] . The data reduction of the raw data is based on the ESO CPL X-shooter pipeline. We paid particular attention to the determination of the response curves [...] We implemented slit-loss correction, absolute flux calibration, (semi-)automatic rectification to the continuum, and a correction for telluric lines. The spectra of individual epochs were corrected for the barycentric motion, re-sampled and co-added, and the spectra from the two arms were merged into a single flux calibrated spectrum covering the entire optical range with maximum signal-to-noise ratio. [...] We provide three types of data products: (i) two-dimensional spectra for each UVB and VIS exposure; (ii) one-dimensional UVB and VIS spectra before and after response-correction, as well as after applying various processing, including absolute flux calibration, telluric removal, normalisation and barycentric correction; and (iii) co-added flux-calibrated and rectified spectra over the full optical range, for which all available XShootU exposures were combined. For many of the targets, the final signal-to-noise ratio per resolution element is above 200 in both the UVB and the VIS co-added spectra. The reduced data and advanced scientific data products will be made available to the community upon publication of this paper. [...] <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.16987v1-abstract-full').style.display = 'none'; document.getElementById('2402.16987v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 19 figures; accepted for publication in Astronomy & Astrophysics. Links to online tables and databases will be included upon publication</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 688, A104 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.06131">arXiv:2311.06131</a> <span> [<a href="https://arxiv.org/pdf/2311.06131">pdf</a>, <a href="https://arxiv.org/format/2311.06131">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202347548">10.1051/0004-6361/202347548 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The onset of stellar multiplicity in massive star formation: A search for low-mass companions of massive young stellar objects with $L'$-band adaptive optics imaging </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bordier%2C+E">E. Bordier</a>, <a href="/search/astro-ph?searchtype=author&query=de+Wit%2C+W+-">W. -J. de Wit</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">A. J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Pauwels%2C+T">T. Pauwels</a>, <a href="/search/astro-ph?searchtype=author&query=Koumpia%2C+E">E. Koumpia</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.06131v1-abstract-short" style="display: inline;"> Given the high incidence of binaries among mature field massive stars, it is clear that multiplicity is an inevitable outcome of high-mass star formation. Understanding how massive multiples form requires the study of the birth environments of massive stars, covering the innermost to outermost regions. We aim to detect and characterise low-mass companions around massive young stellar objects (MYSO… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06131v1-abstract-full').style.display = 'inline'; document.getElementById('2311.06131v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.06131v1-abstract-full" style="display: none;"> Given the high incidence of binaries among mature field massive stars, it is clear that multiplicity is an inevitable outcome of high-mass star formation. Understanding how massive multiples form requires the study of the birth environments of massive stars, covering the innermost to outermost regions. We aim to detect and characterise low-mass companions around massive young stellar objects (MYSOs) during and shortly after their formation phase. To investigate large spatial scales, we carried out an $L'$-band high-contrast direct imaging survey seeking low-mass companions (down to $L_{\text{bol}}\approx 10 L_{\odot}$, or late A-type) around thirteen previously identified MYSOs using the VLT/NACO instrument. From those images, we looked for the presence of companions on a wide orbit, covering scales from 300 to 56,000 au. Detection limits were determined for all targets and we tested the gravitational binding to the central object based on chance projection probabilities. We have discovered a total of thirty-nine potential companions around eight MYSOs, the large majority of which have never been reported to date. We derived a multiplicity frequency (MF) of $62\pm13$% and a companion fraction (CF) of $3.0\pm0.5$. The derived MF and CF are compared to other studies for similar separation ranges. The comparisons are effective for a fixed evolutionary stage spanning a wide range of masses and vice versa. We find an increased MF and CF compared to the previous studies targeting MYSOs, showing that the statement in which multiplicity scales with primary mass also extends to younger evolutionary stages. The separations at which the companions are found and their location with relation to the primary star allow us to discuss the implications for the massive star formation theories. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06131v1-abstract-full').style.display = 'none'; document.getElementById('2311.06131v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">24 pages, 2 Tables, 5 Figures and 4 appendices (containing figures)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 681, A85 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.02705">arXiv:2311.02705</a> <span> [<a href="https://arxiv.org/pdf/2311.02705">pdf</a>, <a href="https://arxiv.org/format/2311.02705">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346847">10.1051/0004-6361/202346847 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> MELCHIORS: The Mercator Library of High Resolution Stellar Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Royer%2C+P">P. Royer</a>, <a href="/search/astro-ph?searchtype=author&query=Merle%2C+T">T. Merle</a>, <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Sekaran%2C+S">S. Sekaran</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Winckel%2C+H">H. Van Winckel</a>, <a href="/search/astro-ph?searchtype=author&query=Fr%C3%A9mat%2C+Y">Y. Fr茅mat</a>, <a href="/search/astro-ph?searchtype=author&query=Van+der+Swaelmen%2C+M">M. Van der Swaelmen</a>, <a href="/search/astro-ph?searchtype=author&query=Gebruers%2C+S">S. Gebruers</a>, <a href="/search/astro-ph?searchtype=author&query=Tkachenko%2C+A">A. Tkachenko</a>, <a href="/search/astro-ph?searchtype=author&query=Laverick%2C+M">M. Laverick</a>, <a href="/search/astro-ph?searchtype=author&query=Dirickx%2C+M">M. Dirickx</a>, <a href="/search/astro-ph?searchtype=author&query=Raskin%2C+G">G. Raskin</a>, <a href="/search/astro-ph?searchtype=author&query=Hensberge%2C+H">H. Hensberge</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Acke%2C+B">B. Acke</a>, <a href="/search/astro-ph?searchtype=author&query=Alonso%2C+M+L">M. L. Alonso</a>, <a href="/search/astro-ph?searchtype=author&query=Mahato%2C+S+B">S. Bandhu Mahato</a>, <a href="/search/astro-ph?searchtype=author&query=Beck%2C+P+G">P. G. Beck</a>, <a href="/search/astro-ph?searchtype=author&query=Behara%2C+N">N. Behara</a>, <a href="/search/astro-ph?searchtype=author&query=Bloemen%2C+S">S. Bloemen</a>, <a href="/search/astro-ph?searchtype=author&query=Buysschaert%2C+B">B. Buysschaert</a>, <a href="/search/astro-ph?searchtype=author&query=Cox%2C+N">N. Cox</a>, <a href="/search/astro-ph?searchtype=author&query=Debosscher%2C+J">J. Debosscher</a>, <a href="/search/astro-ph?searchtype=author&query=De+Cat%2C+P">P. De Cat</a>, <a href="/search/astro-ph?searchtype=author&query=Degroote%2C+P">P. Degroote</a> , et al. (49 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.02705v1-abstract-short" style="display: inline;"> Over the past decades, libraries of stellar spectra have been used in a large variety of science cases, including as sources of reference spectra for a given object or a given spectral type. Despite the existence of large libraries and the increasing number of projects of large-scale spectral surveys, there is to date only one very high-resolution spectral library offering spectra from a few hundr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.02705v1-abstract-full').style.display = 'inline'; document.getElementById('2311.02705v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.02705v1-abstract-full" style="display: none;"> Over the past decades, libraries of stellar spectra have been used in a large variety of science cases, including as sources of reference spectra for a given object or a given spectral type. Despite the existence of large libraries and the increasing number of projects of large-scale spectral surveys, there is to date only one very high-resolution spectral library offering spectra from a few hundred objects from the southern hemisphere (UVES-POP) . We aim to extend the sample, offering a finer coverage of effective temperatures and surface gravity with a uniform collection of spectra obtained in the northern hemisphere. Between 2010 and 2020, we acquired several thousand echelle spectra of bright stars with the Mercator-HERMES spectrograph located in the Roque de Los Muchachos Observatory in La Palma, whose pipeline offers high-quality data reduction products. We have also developed methods to correct for the instrumental response in order to approach the true shape of the spectral continuum. Additionally, we have devised a normalisation process to provide a homogeneous normalisation of the full spectral range for most of the objects. We present a new spectral library consisting of 3256 spectra covering 2043 stars. It combines high signal-to-noise and high spectral resolution over the entire range of effective temperatures and luminosity classes. The spectra are presented in four versions: raw, corrected from the instrumental response, with and without correction from the atmospheric molecular absorption, and normalised (including the telluric correction). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.02705v1-abstract-full').style.display = 'none'; document.getElementById('2311.02705v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 18 figures Preview and access to the library: https://www.royer.se/melchiors.html</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 681, A107 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.13113">arXiv:2309.13113</a> <span> [<a href="https://arxiv.org/pdf/2309.13113">pdf</a>, <a href="https://arxiv.org/format/2309.13113">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346930">10.1051/0004-6361/202346930 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Constraints on the multiplicity of the most massive stars known: R136 a1, a2, a3, and c </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. A. Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Najarro%2C+F">F. Najarro</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">L. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.13113v1-abstract-short" style="display: inline;"> The most massive stars known to date are R 136 a1, a2, a3, and c within the central cluster R 136a of the Tarantula nebula in the Large Magellanic Cloud (LMC), with reported masses in excess of 150-200$M_\odot$. However, the mass estimation of these stars relies on the assumption that they are single. We collected three epochs of spectroscopy for R 136 a1, a2, a3, and c with the Space Telescope Im… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.13113v1-abstract-full').style.display = 'inline'; document.getElementById('2309.13113v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.13113v1-abstract-full" style="display: none;"> The most massive stars known to date are R 136 a1, a2, a3, and c within the central cluster R 136a of the Tarantula nebula in the Large Magellanic Cloud (LMC), with reported masses in excess of 150-200$M_\odot$. However, the mass estimation of these stars relies on the assumption that they are single. We collected three epochs of spectroscopy for R 136 a1, a2, a3, and c with the Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope (HST) in the years 2020-2021 to probe potential radial-velocity (RV) variations. We combine these epochs with an additional HST/STIS observation taken in 2012. We use cross-correlation to quantify the RVs, and establish constraints on possible companions to these stars up to periods of ~10 yr. Objects are classified as binaries when the peak-to-peak RV shifts exceed 50 km/s, and when the RV shift is significant with respect to errors. R 136 a1, a2, and a3 do not satisfy the binary criteria and are thus classified as putatively single, although formal peak-to-peak RV variability on the level 40 km/s is noted for a3. Only R 136 c is classified as binary, in agreement with literature. We can generally rule out massive companions (M2 > ~50 Msun) to R 136 a1, a2, and a3 out to orbital periods of < 1 yr (separations < 5 au) at 95% confidence, or out to tens of years (separations < ~100 au) at 50% confidence. Highly eccentric binaries (e > ~0.9) or twin companions with similar spectra could evade detection down to shorter periods (> ~10 d), though their presence is not supported by the relative X-ray faintness of R 136 a1, a2, and a3. We derive a preliminary orbital solution with a 17.2 d period for the X-ray bright binary R 136 c, though more data are needed to conclusively derive its orbit. Our study supports a lower bound of 150-200 $M_\odot$ on the upper-mass limit at LMC metallicity <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.13113v1-abstract-full').style.display = 'none'; document.getElementById('2309.13113v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 679, A36 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.05736">arXiv:2309.05736</a> <span> [<a href="https://arxiv.org/pdf/2309.05736">pdf</a>, <a href="https://arxiv.org/format/2309.05736">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202347090">10.1051/0004-6361/202347090 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Forming merging double compact objects with stable mass transfer </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Picco%2C+A">Annachiara Picco</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Nelemans%2C+G">Gijs Nelemans</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.05736v1-abstract-short" style="display: inline;"> Merging double compact objects (CO) represent the inferred sources of every detected gravitational wave (GW) signal, thus modeling their progenitors is important to constrain stellar evolution theory. Stable mass transfer (MT) between a donor star and a black hole is one of the proposed tightening mechanisms to form binary black holes merging within the age of the universe. We aim to assess the po… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.05736v1-abstract-full').style.display = 'inline'; document.getElementById('2309.05736v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.05736v1-abstract-full" style="display: none;"> Merging double compact objects (CO) represent the inferred sources of every detected gravitational wave (GW) signal, thus modeling their progenitors is important to constrain stellar evolution theory. Stable mass transfer (MT) between a donor star and a black hole is one of the proposed tightening mechanisms to form binary black holes merging within the age of the universe. We aim to assess the potential of stable non conservative mass transfer to produce the pairings of COs: black holes (BHs), neutron stars (NSs) and white dwarfs (WDs). We study the conditions required for mass transfer between a star and a CO to be stable and to lead to merging binary COs. We use published results for the response of the stellar radii to rapid mass loss; coupled with analytical models for orbital evolution, we determine the boundary for unstable MT and the post interaction properties of binaries undergoing stable MT. We investigate the impact of angular momentum loss prescription in the hardening by accounting for isotropic re emission from the accretor vicinity and mass outflow from the Lagrangian point L2. Stable MT in systems with a CO + Roche lobe filling star, in the limit of isotropic re-emission, is shown to be able to form any pair of merging COs apart from WD + BH. Considering mass outflow from L2, the resulting parameter space for GW progenitors is shifted towards smaller initial mass ratios, ruling out the formation of NS + NS while allowing the production of merging WD + BH pairs. We compare our results with single-degenerate binaries and find that conditions for stable MT to operate are present in nature. We show that stable MT in the isotropic re-emission limit can produce merging binary BHs with mass ratios consistent with the majority of inferred sources of the third Gravitational Wave Transient Catalogue. Angular momentum loss from L2 lifts the achievable final mass ratio. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.05736v1-abstract-full').style.display = 'none'; document.getElementById('2309.05736v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 17 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 681, A31 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.14799">arXiv:2308.14799</a> <span> [<a href="https://arxiv.org/pdf/2308.14799">pdf</a>, <a href="https://arxiv.org/format/2308.14799">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202345950">10.1051/0004-6361/202345950 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The young massive SMC cluster NGC 330 seen by MUSE III. Stellar parameters and rotational velocities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Dufton%2C+P+L">P. L. Dufton</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+C">C. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">G. Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=de+Mink%2C+S+E">S. E. de Mink</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+C+J">C. J. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B6tberg%2C+Y">Y. G枚tberg</a>, <a href="/search/astro-ph?searchtype=author&query=H%C3%A9nault-Brunet%2C+V">V. H茅nault-Brunet</a>, <a href="/search/astro-ph?searchtype=author&query=Patrick%2C+L+R">L. R. Patrick</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+F+R+N">F. R. N. Schneider</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.14799v1-abstract-short" style="display: inline;"> The origin of initial rotation rates of stars, and how a star's surface rotational velocity changes during the evolution, either by internal angular momentum transport or due to interactions with a binary companion, remain open questions in stellar astrophysics. Here, we aim to derive the physical parameters and study the distribution of (projected) rotational velocities of B-type stars in the 35… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14799v1-abstract-full').style.display = 'inline'; document.getElementById('2308.14799v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.14799v1-abstract-full" style="display: none;"> The origin of initial rotation rates of stars, and how a star's surface rotational velocity changes during the evolution, either by internal angular momentum transport or due to interactions with a binary companion, remain open questions in stellar astrophysics. Here, we aim to derive the physical parameters and study the distribution of (projected) rotational velocities of B-type stars in the 35 Myr-old, massive cluster NGC 330 in the Small Magellanic Cloud. NGC 330 is in an age range where the number of post-interaction binaries is predicted to be high near the cluster turnoff (TO). We develop a simultaneous photometric and spectroscopic grid-fitting method adjusting atmosphere models on multi-band Hubble Space Telescope photometry and Multi Unit Spectroscopic Explorer spectroscopy. This allows us to homogeneously constrain the physical parameters of over 250 B and Be stars, brighter than mF814W = 18.8 mag. The rotational velocities of Be stars in NGC 330 are significantly higher than the ones of B stars. The rotational velocities vary as a function of the star's position in the color-magnitude diagram, qualitatively following predictions of binary population synthesis. A comparison to younger clusters shows that stars in NGC 330 rotate more rapidly on average. The rotational velocities of the 35 Myr old population in NGC 330 quantitatively agree with predictions for a stellar population that underwent significant binary interactions: the bulk of the B stars could be single stars or primaries in pre-interaction binaries. The rapidly spinning Be stars could be mass and angular momentum gainers in previous interactions, while those Be stars close to the TO may be spun-up single stars. The slowly rotating, apparently single stars above the TO could be merger products. The different vsini-characteristics of NGC 330 compared to younger populations can be understood in this framework. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14799v1-abstract-full').style.display = 'none'; document.getElementById('2308.14799v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages (incl. appendix), 15 figures, 3 tables, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 680, A32 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.08642">arXiv:2308.08642</a> <span> [<a href="https://arxiv.org/pdf/2308.08642">pdf</a>, <a href="https://arxiv.org/format/2308.08642">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202347318">10.1051/0004-6361/202347318 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> MWC 656 is unlikely to contain a black hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Janssens%2C+S">S. Janssens</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Degenaar%2C+N">N. Degenaar</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Audenaert%2C+J">J. Audenaert</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">A. J. Frost</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.08642v2-abstract-short" style="display: inline;"> Context. MWC 656 was reported as the first known Be star with a black-hole (BH) companion in a 60 d period. The mass of the proposed BH companion is estimated to be between 4 - 7 MSun. This estimate is based on radial velocity (RV) measurements derived from the Fe ii 4583 emission line of the Be star disc and from the He ii 4686 emission line, assumed to be formed in a disc around the putative BH.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.08642v2-abstract-full').style.display = 'inline'; document.getElementById('2308.08642v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.08642v2-abstract-full" style="display: none;"> Context. MWC 656 was reported as the first known Be star with a black-hole (BH) companion in a 60 d period. The mass of the proposed BH companion is estimated to be between 4 - 7 MSun. This estimate is based on radial velocity (RV) measurements derived from the Fe ii 4583 emission line of the Be star disc and from the He ii 4686 emission line, assumed to be formed in a disc around the putative BH. Aims. Using new high-resolution spectroscopic data, we investigate whether MWC 656 truly contains a BH. Methods. We used the cross-correlation method to calculate the RVs of both the Be star and the He ii 4686 emission line and we derive a new orbital solution. We also performed disentangling to look for the spectral signature of a companion. Results. We derive an orbital period of 59.028 +- 0.011 d and a mass ratio q = M_Heii/M_Be = 0.12 +- 0.03, much lower than the previously reported q = 0.41 +- 0.07. Adopting a mass of the Be star of M_Be = 7.8 +- 2.0MSun, the companion has a mass of 0.94 +- 0.34MSun. For the upper limit of M_Be = 16MSun and q = 0.15, the companion has a mass 2.4MSun. Performing disentangling on mock spectra shows that the spectral signature of a non-degenerate stellar companion with such a low mass cannot be retrieved using our data. Conclusions. Our measurements do not support the presence of a BH companion in MWC 656. The derived upper limit on the mass of the companion rather indicates that it is a neutron star, a white dwarf, or a hot helium star. Far-UV data will help to reject or confirm a hot helium-star companion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.08642v2-abstract-full').style.display = 'none'; document.getElementById('2308.08642v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 2 + 6 figures, 3 + 1 tables, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 677, L9 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.08591">arXiv:2308.08591</a> <span> [<a href="https://arxiv.org/pdf/2308.08591">pdf</a>, <a href="https://arxiv.org/format/2308.08591">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1126/science.ade3293">10.1126/science.ade3293 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A massive helium star with a sufficiently strong magnetic field to form a magnetar </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Wade%2C+G+A">G. A. Wade</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Bagnulo%2C+S">S. Bagnulo</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Gilkis%2C+A">A. Gilkis</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Chene%2C+A+-">A. -N. Chene</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">L. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Reeth%2C+T">T. Van Reeth</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=St-Louis%2C+N">N. St-Louis</a>, <a href="/search/astro-ph?searchtype=author&query=de+Oliveira%2C+A+S">A. Soares de Oliveira</a>, <a href="/search/astro-ph?searchtype=author&query=Todt%2C+H">H. Todt</a>, <a href="/search/astro-ph?searchtype=author&query=Toonen%2C+S">S. Toonen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.08591v1-abstract-short" style="display: inline;"> Magnetars are highly magnetized neutron stars; their formation mechanism is unknown. Hot helium-rich stars with spectra dominated by emission lines are known as Wolf-Rayet stars. We observe the binary system HD 45166 using spectropolarimetry, finding that it contains a Wolf-Rayet star with a mass of 2 solar masses and a magnetic field of 43 kilogauss. Stellar evolution calculations indicate that t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.08591v1-abstract-full').style.display = 'inline'; document.getElementById('2308.08591v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.08591v1-abstract-full" style="display: none;"> Magnetars are highly magnetized neutron stars; their formation mechanism is unknown. Hot helium-rich stars with spectra dominated by emission lines are known as Wolf-Rayet stars. We observe the binary system HD 45166 using spectropolarimetry, finding that it contains a Wolf-Rayet star with a mass of 2 solar masses and a magnetic field of 43 kilogauss. Stellar evolution calculations indicate that this component will explode as a type Ib or IIb supernova, and the strong magnetic field favors a magnetar remnant. We propose that the magnatized Wolf-Rayet star formed by the merger of two lower mass helium stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.08591v1-abstract-full').style.display = 'none'; document.getElementById('2308.08591v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in Science on the 18 August 2023. Radial velocities, spectra, and software available in: https://zenodo.org/record/8042656 ESO press release: www.eso.org/public/news/eso2313</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.13500">arXiv:2307.13500</a> <span> [<a href="https://arxiv.org/pdf/2307.13500">pdf</a>, <a href="https://arxiv.org/format/2307.13500">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202245324">10.1051/0004-6361/202245324 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The multiplicity of massive stars in the Scorpius OB1 association through high-contrast imaging </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pauwels%2C+T">Tinne Pauwels</a>, <a href="/search/astro-ph?searchtype=author&query=Reggiani%2C+M">Maddalena Reggiani</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Rainot%2C+A">Alan Rainot</a>, <a href="/search/astro-ph?searchtype=author&query=Kratter%2C+K">Kaitlin Kratter</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.13500v1-abstract-short" style="display: inline;"> One of the most remarkable properties of massive stars is that almost all of them are found in binaries or higher-order multiple systems. Observations that cover the full companion mass ratio and separation regime are essential to constrain massive star and binary formation theories. We used VLT/SPHERE to characterise the multiplicity properties of 20 OB stars in the active star-forming region Sco… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.13500v1-abstract-full').style.display = 'inline'; document.getElementById('2307.13500v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.13500v1-abstract-full" style="display: none;"> One of the most remarkable properties of massive stars is that almost all of them are found in binaries or higher-order multiple systems. Observations that cover the full companion mass ratio and separation regime are essential to constrain massive star and binary formation theories. We used VLT/SPHERE to characterise the multiplicity properties of 20 OB stars in the active star-forming region Sco OB1. We simultaneously observed with the IFS and IRDIS instruments, obtaining high-contrast imaging observations that cover a field of view of 1".73 x 1".73 in YJH bands and 11" x 12".5 in $K_1$ and $K_2$ bands, respectively, corresponding to a separation range between $\sim$200 and 9000 AU. The observations reach contrast magnitudes down to $螖K_1 \sim 13$, allowing us to detect companions at the stellar-substellar boundary. In total, we detect 789 sources, most of which are likely background or foreground objects. We obtain SPHERE companion fractions of $2.3 \pm 0.4$ and $4.2 \pm 0.8$ for O- and B-type stars, respectively. Including all previously detected companions, we find a total multiplicity fraction of $0.89\pm0.07$ for our sample in the range of $\sim$0-12000 AU. In conclusion, SPHERE explores an as of yet uncharted territory of companions around massive stars, which is crucial to ultimately improve our understanding of massive star and binary formation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.13500v1-abstract-full').style.display = 'none'; document.getElementById('2307.13500v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 10 figures, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 678, A172 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.07766">arXiv:2307.07766</a> <span> [<a href="https://arxiv.org/pdf/2307.07766">pdf</a>, <a href="https://arxiv.org/format/2307.07766">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stad2533">10.1093/mnras/stad2533 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The B-type Binaries Characterisation Programme II. VFTS 291: A stripped star from a recent mass transfer phase </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Villase%C3%B1or%2C+J+I">J. I. Villase帽or</a>, <a href="/search/astro-ph?searchtype=author&query=Lennon%2C+D+J">D. J. Lennon</a>, <a href="/search/astro-ph?searchtype=author&query=Picco%2C+A">A. Picco</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Dufton%2C+P+L">P. L. Dufton</a>, <a href="/search/astro-ph?searchtype=author&query=Nardini%2C+F">F. Nardini</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+C+J">C. J. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=de+Mink%2C+S+E">S. E. de Mink</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B6tberg%2C+Y">Y. G枚tberg</a>, <a href="/search/astro-ph?searchtype=author&query=Soszy%C5%84ski%2C+I">I. Soszy艅ski</a>, <a href="/search/astro-ph?searchtype=author&query=Taylor%2C+W+D">W. D. Taylor</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.07766v3-abstract-short" style="display: inline;"> Recent studies of massive binaries with putative black hole companions have uncovered a phase of binary evolution that has not been observed before, featuring a bloated stripped star that very recently ceased transferring mass to a main-sequence companion. In this study, we focus on the candidate system VFTS 291, a binary with an orbital period of 108 d and a high semi-amplitude velocity (… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.07766v3-abstract-full').style.display = 'inline'; document.getElementById('2307.07766v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.07766v3-abstract-full" style="display: none;"> Recent studies of massive binaries with putative black hole companions have uncovered a phase of binary evolution that has not been observed before, featuring a bloated stripped star that very recently ceased transferring mass to a main-sequence companion. In this study, we focus on the candidate system VFTS 291, a binary with an orbital period of 108 d and a high semi-amplitude velocity ($K_1=93.7\pm0.2$ km s$^{-1}$). Through our analysis of the disentangled spectra of the two components, together with dynamical and evolutionary arguments, we identify a narrow-lined star of ~1.5-2.5 $M_\odot$ dominating the spectrum, and an early B-type main-sequence companion of $13.2\pm1.5$ $M_\odot$. The low mass of the narrow-lined star, and the high mass ratio, suggest that VFTS 291 is a post-mass-transfer system, with the narrow-lined star being bloated and stripped of its hydrogen-rich envelope, sharing many similarities with other recently discovered stripped stars. Our finding is supported by our detailed binary evolution models, which indicate that the system can be well explained by an initial configuration consisting of an 8.1 $M_\odot$ primary with an 8 $M_\odot$ companion in a 7 d orbital period. While some open questions remain, particularly concerning the surface helium enrichment of the stripped star and the rotational velocity of the companion, we expect that high-resolution spectroscopy may help reconcile our estimates with theory. Our study highlights the importance of multi-epoch spectroscopic surveys to identify and characterize binary interaction products, and provides important insights into the evolution of massive binary stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.07766v3-abstract-full').style.display = 'none'; document.getElementById('2307.07766v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">25 pages, 17 figures. Published by MNRAS, Advance Access</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.19948">arXiv:2305.19948</a> <span> [<a href="https://arxiv.org/pdf/2305.19948">pdf</a>, <a href="https://arxiv.org/format/2305.19948">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346108">10.1051/0004-6361/202346108 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The ESO UVES/FEROS Large Programs of TESS OB pulsators. I. Global stellar parameters from high-resolution spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Serebriakova%2C+N">Nadya Serebriakova</a>, <a href="/search/astro-ph?searchtype=author&query=Tkachenko%2C+A">Andrew Tkachenko</a>, <a href="/search/astro-ph?searchtype=author&query=Gebruers%2C+S">Sarah Gebruers</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">Dominic M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Reeth%2C+T">Timothy Van Reeth</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Burssens%2C+S">Siemen Burssens</a>, <a href="/search/astro-ph?searchtype=author&query=IJspeert%2C+L">Luc IJspeert</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Aerts%2C+C">Conny Aerts</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.19948v1-abstract-short" style="display: inline;"> Modern stellar structure and evolution theory experiences a lack of observational calibrations for the interior physics of intermediate- and high-mass stars. This leads to discrepancies between theoretical predictions and observed phenomena mostly related to angular momentum and element transport. Analyses of large samples of massive stars connecting state-of-the-art spectroscopy to asteroseismolo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.19948v1-abstract-full').style.display = 'inline'; document.getElementById('2305.19948v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.19948v1-abstract-full" style="display: none;"> Modern stellar structure and evolution theory experiences a lack of observational calibrations for the interior physics of intermediate- and high-mass stars. This leads to discrepancies between theoretical predictions and observed phenomena mostly related to angular momentum and element transport. Analyses of large samples of massive stars connecting state-of-the-art spectroscopy to asteroseismology may provide clues on how to improve our understanding of their interior structure. We aim to deliver a sample of O- and B-type stars at metallicity regimes of the Milky Way and the Large Magellanic Cloud (LMC) galaxies with accurate atmospheric parameters from high-resolution spectroscopy, along with a detailed investigation of line-profile broadening, for future asteroseismic studies. After describing the general aims of our two Large Programs, we develop dedicated methodology to fit spectral lines and deduce accurate global stellar parameters from high-resolution multi-epoch UVES and FEROS spectroscopy. We use the best available atmosphere models for three regimes covered by our global sample, given its breadth in terms of mass, effective temperature, and evolutionary stage. Aside from accurate atmospheric parameters and locations in the Hertzsprung-Russell diagram, we deliver detailed analyses of macroturbulent line broadening, including estimation of the radial and tangential components. We find that these two components are difficult to disentangle from spectra with signal-to-noise ratios below 250. Future asteroseismic modelling of the deep interior physics of the most promising stars in our sample will improve the existing dearth of such knowledge for large samples of OB stars, including those of low metallicity in the LMC. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.19948v1-abstract-full').style.display = 'none'; document.getElementById('2305.19948v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 676, A85 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.06376">arXiv:2305.06376</a> <span> [<a href="https://arxiv.org/pdf/2305.06376">pdf</a>, <a href="https://arxiv.org/format/2305.06376">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202245650">10.1051/0004-6361/202245650 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-Shooting ULLYSES: massive stars at low metallicity. I. Project Description </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">Jorick S. Vink</a>, <a href="/search/astro-ph?searchtype=author&query=Mehner%2C+A">A. Mehner</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Fullerton%2C+A">A. Fullerton</a>, <a href="/search/astro-ph?searchtype=author&query=Garcia%2C+M">M. Garcia</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+F">F. Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=St-Louis%2C+N">N. St-Louis</a>, <a href="/search/astro-ph?searchtype=author&query=ud-Doula%2C+A">A. ud-Doula</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Bouret%2C+J+-">J. -C. Bouret</a>, <a href="/search/astro-ph?searchtype=author&query=Kubatova%2C+B">B. Kubatova</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+L+P">L. P. Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Wofford%2C+A">A. Wofford</a>, <a href="/search/astro-ph?searchtype=author&query=van+Loon%2C+J+T">J. Th. van Loon</a>, <a href="/search/astro-ph?searchtype=author&query=Telford%2C+O+G">O. Grace Telford</a>, <a href="/search/astro-ph?searchtype=author&query=Gotberg%2C+Y">Y. Gotberg</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Erba%2C+C">C. Erba</a>, <a href="/search/astro-ph?searchtype=author&query=Kalari%2C+V+M">V. M. Kalari</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Alkousa%2C+T">T. Alkousa</a> , et al. (56 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.06376v3-abstract-short" style="display: inline;"> Observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational-wave events involving spectacular black-hole mergers, indicate that the low-metallicity Universe is fundamentally different from our own Galaxy. Many transient phenomena will remain enigmatic until we achieve a firm understanding of the physics and evolution of massive stars at low metallicity… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.06376v3-abstract-full').style.display = 'inline'; document.getElementById('2305.06376v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.06376v3-abstract-full" style="display: none;"> Observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational-wave events involving spectacular black-hole mergers, indicate that the low-metallicity Universe is fundamentally different from our own Galaxy. Many transient phenomena will remain enigmatic until we achieve a firm understanding of the physics and evolution of massive stars at low metallicity (Z). The Hubble Space Telescope has devoted 500 orbits to observe 250 massive stars at low Z in the ultraviolet (UV) with the COS and STIS spectrographs under the ULLYSES program. The complementary ``X-Shooting ULLYSES'' (XShootU) project provides enhanced legacy value with high-quality optical and near-infrared spectra obtained with the wide-wavelength coverage X-shooter spectrograph at ESO's Very Large Telescope. We present an overview of the XShootU project, showing that combining ULLYSES UV and XShootU optical spectra is critical for the uniform determination of stellar parameters such as effective temperature, surface gravity, luminosity, and abundances, as well as wind properties such as mass-loss rates in function of Z. As uncertainties in stellar and wind parameters percolate into many adjacent areas of Astrophysics, the data and modelling of the XShootU project is expected to be a game-changer for our physical understanding of massive stars at low Z. To be able to confidently interpret James Webb Space Telescope (JWST) spectra of the first stellar generations, the individual spectra of low Z stars need to be understood, which is exactly where XShootU can deliver. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.06376v3-abstract-full').style.display = 'none'; document.getElementById('2305.06376v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in A&A - 35 Pages, 12 Figures, 4 Tables, 2 Large Tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 675, A154 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.12165">arXiv:2303.12165</a> <span> [<a href="https://arxiv.org/pdf/2303.12165">pdf</a>, <a href="https://arxiv.org/format/2303.12165">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202245588">10.1051/0004-6361/202245588 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-Shooting ULLYSES: Massive stars at low metallicity. III. Terminal wind speeds of ULLYSES massive stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J+O">J. O. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Bestenlehner%2C+J+M">J. M. Bestenlehner</a>, <a href="/search/astro-ph?searchtype=author&query=Brands%2C+S+A">S. A. Brands</a>, <a href="/search/astro-ph?searchtype=author&query=David-Uraz%2C+A">A. David-Uraz</a>, <a href="/search/astro-ph?searchtype=author&query=Decin%2C+L">L. Decin</a>, <a href="/search/astro-ph?searchtype=author&query=Erba%2C+C">C. Erba</a>, <a href="/search/astro-ph?searchtype=author&query=Garcia%2C+M">M. Garcia</a>, <a href="/search/astro-ph?searchtype=author&query=Hamann%2C+W+-">W. -R. Hamann</a>, <a href="/search/astro-ph?searchtype=author&query=Herrero%2C+A">A. Herrero</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Kee%2C+N+D">N. D. Kee</a>, <a href="/search/astro-ph?searchtype=author&query=Kub%C3%A1tov%C3%A1%2C+B">B. Kub谩tov谩</a>, <a href="/search/astro-ph?searchtype=author&query=Lefever%2C+R">R. Lefever</a>, <a href="/search/astro-ph?searchtype=author&query=Moffat%2C+A">A. Moffat</a>, <a href="/search/astro-ph?searchtype=author&query=Najarro%2C+F">F. Najarro</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">L. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Pauli%2C+D">D. Pauli</a>, <a href="/search/astro-ph?searchtype=author&query=Prinja%2C+R">R. Prinja</a>, <a href="/search/astro-ph?searchtype=author&query=Puls%2C+J">J. Puls</a>, <a href="/search/astro-ph?searchtype=author&query=Sander%2C+A+A+C">A. A. C. Sander</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.12165v2-abstract-short" style="display: inline;"> The winds of massive stars have an impact on stellar evolution and on the surrounding medium. The maximum speed reached by these outflows, the terminal wind speed, is a global wind parameter and an essential input for models of stellar atmospheres and feedback. With the arrival of the ULLYSES programme, a legacy UV spectroscopic survey with HST, we have the opportunity to quantify the wind speeds… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12165v2-abstract-full').style.display = 'inline'; document.getElementById('2303.12165v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.12165v2-abstract-full" style="display: none;"> The winds of massive stars have an impact on stellar evolution and on the surrounding medium. The maximum speed reached by these outflows, the terminal wind speed, is a global wind parameter and an essential input for models of stellar atmospheres and feedback. With the arrival of the ULLYSES programme, a legacy UV spectroscopic survey with HST, we have the opportunity to quantify the wind speeds of massive stars at sub-solar metallicity (in the Large and Small Magellanic Clouds, 0.5Z and 0.2Z) at an unprecedented scale. We empirically quantify the wind speeds of a large sample of OB stars, including supergiants, giants, and dwarfs at sub-solar metallicity. Using these measurements, we investigate trends of terminal wind speed with a number of fundamental stellar parameters, namely effective temperature, metallicity, and surface escape velocity. We empirically determined the terminal wind speed for a sample of 149 OB stars in the Magellanic Clouds either by directly measuring the maximum velocity shift of the absorption component of the Civ 1548-1550 line profile, or by fitting synthetic spectra produced using the Sobolev with exact integration method. Stellar parameters were either collected from the literature, obtained using spectral-type calibrations, or predicted from evolutionary models. We find strong trends of terminal wind speed with effective temperature and surface escape speed when the wind is strong enough to cause a saturated P Cygni profile in Civ 1548-1550. We find evidence for a metallicity dependence on the terminal wind speed proportional to Z^0.22+-0.03 when we compared our results to previous Galactic studies. Our results suggest that effective temperature rather than surface escape speed should be used as a straightforward empirical prediction of terminal wind speed and that the observed metallicity dependence is steeper than suggested by earlier works. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12165v2-abstract-full').style.display = 'none'; document.getElementById('2303.12165v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 16 figures, 8 tables. Accepted in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 688, A105 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.09385">arXiv:2303.09385</a> <span> [<a href="https://arxiv.org/pdf/2303.09385">pdf</a>, <a href="https://arxiv.org/format/2303.09385">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244635">10.1051/0004-6361/202244635 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> ALMA detection of CO rotational line emission in red supergiant stars of the massive young star cluster RSGC1 -- Determination of a new mass-loss rate prescription for red supergiants </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Decin%2C+L">Leen Decin</a>, <a href="/search/astro-ph?searchtype=author&query=Richards%2C+A+M+S">Anita M. S. Richards</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.09385v2-abstract-short" style="display: inline;"> [Abridged] Aim: We aim to derive a new mass-loss rate prescription for RSGs that is not afflicted with some uncertainties inherent in preceding studies. Methods: We have observed CO rotational line emission towards a sample of RSGs in the open cluster RSGC1 that all are of similar initial mass. The ALMA CO(2-1) line detections allow to retrieve the gas mass-loss rates (Mdot_CO). In contrast to mas… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.09385v2-abstract-full').style.display = 'inline'; document.getElementById('2303.09385v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.09385v2-abstract-full" style="display: none;"> [Abridged] Aim: We aim to derive a new mass-loss rate prescription for RSGs that is not afflicted with some uncertainties inherent in preceding studies. Methods: We have observed CO rotational line emission towards a sample of RSGs in the open cluster RSGC1 that all are of similar initial mass. The ALMA CO(2-1) line detections allow to retrieve the gas mass-loss rates (Mdot_CO). In contrast to mass-loss rates derived from the analysis of dust spectral features (Mdot_SED), the data allow a direct determination of the wind velocity and no uncertain dust-to-gas correction factor is needed. Results: Five RSGs in RSGC1 have been detected in CO(2-1). The retrieved Mdot_CO values are systematically lower than Mdot_SED. Although only five RSGs in RSGC1 have been detected, the data allow to propose a new mass-loss rate relation for M-type red supergiants that is dependent on luminosity and initial mass. The new mass-loss rate relation is based on the new Mdot_CO values for the RSGs in RSGC1 and on prior Mdot_SED values for RSGs in 4 clusters, including RSGC1. The new Mdot-prescription yields a good prediction for the mass-loss rate of some well-known Galactic RSGs that are observed in multiple CO rotational lines, including alpha Ori, mu Cep and VX Sgr. However, there are indications that a stronger, potentially eruptive, mass-loss process - different than captured by our new mass-loss rate prescription - is occurring during some fraction of the RSG lifetime. Implementing a lower mass-loss rate in evolution codes for massive stars has important consequences for the nature of their end-state. A reduction of the RSG mass-loss rate implies that quiescent RSG mass loss is not enough to strip a single star's hydrogen-rich envelope. Upon core-collapse such single stars would explode as RSG. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.09385v2-abstract-full').style.display = 'none'; document.getElementById('2303.09385v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages, submitted to Astronomy & Astrophysics, minor revisions already implemented</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 681, A17 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.09328">arXiv:2303.09328</a> <span> [<a href="https://arxiv.org/pdf/2303.09328">pdf</a>, <a href="https://arxiv.org/format/2303.09328">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346277">10.1051/0004-6361/202346277 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Modeling contact binaries, II. The effect of energy transfer </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">Matthias Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">Norbert Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.09328v1-abstract-short" style="display: inline;"> Context. It is common for massive stars to engage in binary interaction. In close binaries, the components can enter a contact phase, where both stars overflow their respective Roche lobes simultaneously. While there exist observational constraints on the stellar properties of such systems, the most detailed stellar evolution models that feature a contact phase are not fully reconcilable with thos… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.09328v1-abstract-full').style.display = 'inline'; document.getElementById('2303.09328v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.09328v1-abstract-full" style="display: none;"> Context. It is common for massive stars to engage in binary interaction. In close binaries, the components can enter a contact phase, where both stars overflow their respective Roche lobes simultaneously. While there exist observational constraints on the stellar properties of such systems, the most detailed stellar evolution models that feature a contact phase are not fully reconcilable with those measurements. Aims. We aim to consistently model contact phases of binary stars in a 1D stellar evolution code. To this end, we develop the methodology to account for energy transfer in the common contact layers. Methods. We implement an approximative model for energy transfer between the components of a contact binary based on the von Zeipel theorem in the stellar evolution code MESA. We compare structure and evolution models with and without this transfer and analyze the implications for the observable properties of the contact phase. Results. Implementing energy transfer helps eliminating baroclinicity in the common envelope between the components of a contact binary, which, if present, would drive strong thermal flows. We find that accounting for energy transfer in massive contact binaries significantly alters the mass ratio evolution and can extend the lifetime of an unequal mass ratio contact system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.09328v1-abstract-full').style.display = 'none'; document.getElementById('2303.09328v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 5 figures. Accepted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 672, A175 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.08892">arXiv:2303.08892</a> <span> [<a href="https://arxiv.org/pdf/2303.08892">pdf</a>, <a href="https://arxiv.org/format/2303.08892">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202243611">10.1051/0004-6361/202243611 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The dusty circumstellar environment of Betelgeuse during the Great Dimming as seen by VLTI/MATISSE </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cannon%2C+E">E. Cannon</a>, <a href="/search/astro-ph?searchtype=author&query=Montarg%C3%A8s%2C+M">M. Montarg猫s</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Matter%2C+A">A. Matter</a>, <a href="/search/astro-ph?searchtype=author&query=Sanchez-Bermudez%2C+J">J. Sanchez-Bermudez</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R">R. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Paladini%2C+C">C. Paladini</a>, <a href="/search/astro-ph?searchtype=author&query=Decin%2C+L">L. Decin</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J+O">J. O. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Lagadec%2C+E">E. Lagadec</a>, <a href="/search/astro-ph?searchtype=author&query=Kervella%2C+P">P. Kervella</a>, <a href="/search/astro-ph?searchtype=author&query=Chiavassa%2C+A">A. Chiavassa</a>, <a href="/search/astro-ph?searchtype=author&query=Dupree%2C+A+K">A. K. Dupree</a>, <a href="/search/astro-ph?searchtype=author&query=Perrin%2C+G">G. Perrin</a>, <a href="/search/astro-ph?searchtype=author&query=Scicluna%2C+P">P. Scicluna</a>, <a href="/search/astro-ph?searchtype=author&query=Stee%2C+P">P. Stee</a>, <a href="/search/astro-ph?searchtype=author&query=Kraus%2C+S">S. Kraus</a>, <a href="/search/astro-ph?searchtype=author&query=Danchi%2C+W">W. Danchi</a>, <a href="/search/astro-ph?searchtype=author&query=Lopez%2C+B">B. Lopez</a>, <a href="/search/astro-ph?searchtype=author&query=Millour%2C+F">F. Millour</a>, <a href="/search/astro-ph?searchtype=author&query=Drevon%2C+J">J. Drevon</a>, <a href="/search/astro-ph?searchtype=author&query=Cruzal%C3%A8bes%2C+P">P. Cruzal猫bes</a>, <a href="/search/astro-ph?searchtype=author&query=Berio%2C+P">P. Berio</a>, <a href="/search/astro-ph?searchtype=author&query=Robbe-Dubois%2C+S">S. Robbe-Dubois</a> , et al. (1 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.08892v1-abstract-short" style="display: inline;"> The 'Great Dimming' of the prototypical red supergiant Betelgeuse, which occurred between December 2019 and April 2020, gives us unprecedented insight into the processes occurring on the stellar surface and in the inner wind of this type of star. In particular it may bring further understanding of their dust nucleation and mass loss processes. Here, we present and analyse VLTI/MATISSE observations… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.08892v1-abstract-full').style.display = 'inline'; document.getElementById('2303.08892v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.08892v1-abstract-full" style="display: none;"> The 'Great Dimming' of the prototypical red supergiant Betelgeuse, which occurred between December 2019 and April 2020, gives us unprecedented insight into the processes occurring on the stellar surface and in the inner wind of this type of star. In particular it may bring further understanding of their dust nucleation and mass loss processes. Here, we present and analyse VLTI/MATISSE observations in the N-band (8 - 13 $渭$m) taken near the brightness minimum in order to assess the status of the dusty circumstellar environment. We explore the compatibility of a dust clump obscuring the star with our mid-infrared interferometric observations using continuum 3D radiative transfer modelling, and probe the effect of adding multiple clumps close to the star on the observables. We also test the viability of a large cool spot on the stellar surface without dust present in the ambient medium. Using the visibility data, we derive a uniform disk diameter of 59.02 $\pm$ 0.64 mas in the spectral range 8 to 8.75 $渭$m. We find that both the dust clump and the cool spot models are compatible with the data. Further to this, we note that the extinction and emission of our localised dust clump in the line of sight of the star, directly compensate each other making the clump undetectable in the spectral energy distribution and visibilities. The lack of infrared brightening during the 'Great Dimming' therefore does not exclude extinction due to a dust clump as one of the possible mechanisms. The visibilities can be reproduced by a spherical wind with dust condensing at 13 stellar radii and a dust mass-loss rate of (2.1 - 4.9) $\times$ 10$^{-10}$ $\mathit{M}_{\odot} {\rm yr}^{-1}$, however, in order to reproduce the complexity of the observed closure phases, additional surface features or dust clumps would be needed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.08892v1-abstract-full').style.display = 'none'; document.getElementById('2303.08892v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 Pages, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 675, A46 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.07369">arXiv:2303.07369</a> <span> [<a href="https://arxiv.org/pdf/2303.07369">pdf</a>, <a href="https://arxiv.org/ps/2303.07369">ps</a>, <a href="https://arxiv.org/format/2303.07369">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stad764">10.1093/mnras/stad764 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Updated radial velocities and new constraints on the nature of the unseen source in NGC1850 BH1 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Saracino%2C+S">Sara Saracino</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">Tomer Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Kamann%2C+S">Sebastian Kamann</a>, <a href="/search/astro-ph?searchtype=author&query=Bastian%2C+N">Nate Bastian</a>, <a href="/search/astro-ph?searchtype=author&query=Gieles%2C+M">Mark Gieles</a>, <a href="/search/astro-ph?searchtype=author&query=Usher%2C+C">Christopher Usher</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">Julia Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Kochoska%2C+A">Angela Kochoska</a>, <a href="/search/astro-ph?searchtype=author&query=Orosz%2C+J+A">Jerome A. Orosz</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.07369v1-abstract-short" style="display: inline;"> A black hole candidate orbiting a luminous star in the Large Magellanic Cloud young cluster NGC 1850 ($\sim100$Myr) has recently been reported based on radial velocity and light curve modelling. Subsequently, an alternative explanation has been suggested for the system: a bloated post-mass transfer secondary star (M$_{\rm initial} \sim 4-5M_{\odot}$, M$_{\rm current} \sim 1-2M_{\odot}$) with a mor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.07369v1-abstract-full').style.display = 'inline'; document.getElementById('2303.07369v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.07369v1-abstract-full" style="display: none;"> A black hole candidate orbiting a luminous star in the Large Magellanic Cloud young cluster NGC 1850 ($\sim100$Myr) has recently been reported based on radial velocity and light curve modelling. Subsequently, an alternative explanation has been suggested for the system: a bloated post-mass transfer secondary star (M$_{\rm initial} \sim 4-5M_{\odot}$, M$_{\rm current} \sim 1-2M_{\odot}$) with a more massive, yet luminous companion (the primary). Upon reanalysis of the MUSE spectra, we found that the radial velocity variations originally reported were underestimated ($K_{\rm 2,revised} = 176\pm3$km/s vs $K_{\rm 2,original} = 140\pm3$km/s) because of the weighting scheme adopted in the full-spectrum fitting analysis. The increased radial velocity semi-amplitude translates into a system mass function larger than previously deduced ($f_{\rm revised}$=2.83$M_{\odot}$ vs $f_{\rm original}$=1.42$M_{\odot}$). By exploiting the spectral disentangling technique, we place an upper limit of 10\% of a luminous primary source to the observed optical light in NGC1850 BH1, assuming that the primary and secondary are the only components contributing to the system. Furthermore, by analysing archival near-infrared data, we find clues to the presence of an accretion disk in the system. These constraints support a low-mass post-mass transfer star but do not provide a definitive answer whether the unseen component in NGC1850 BH1 is indeed a black hole. These results predict a scenario where, if a primary luminous source of mass M $\ge 4.7M_{\odot}$, is present in the system (given the inclination and secondary mass constraints), it must be hidden in a optically thick disk to be undetected in the MUSE spectra. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.07369v1-abstract-full').style.display = 'none'; document.getElementById('2303.07369v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 8 Figures and 2 Tables. Accepted for publication by MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.04491">arXiv:2302.04491</a> <span> [<a href="https://arxiv.org/pdf/2302.04491">pdf</a>, <a href="https://arxiv.org/format/2302.04491">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202245378">10.1051/0004-6361/202245378 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Reverse Algols and hydrogen-rich Wolf-Rayet stars from very massive binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sen%2C+K">K. Sen</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Pauli%2C+D">D. Pauli</a>, <a href="/search/astro-ph?searchtype=author&query=Gr%C3%A4fener%2C+G">G. Gr盲fener</a>, <a href="/search/astro-ph?searchtype=author&query=Schootemeijer%2C+A">A. Schootemeijer</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+C">C. Wang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.04491v1-abstract-short" style="display: inline;"> Massive star feedback affects the evolution of galaxies, where the most massive stars may have the largest impact. The majority of massive stars are born as members of close binary systems. Here, we investigate detailed evolutionary models of very massive binaries (30$\dots$90$M_{\odot}$) with Large Magellanic Cloud (LMC) metallicity. We identify four effects defying the conventional knowledge of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04491v1-abstract-full').style.display = 'inline'; document.getElementById('2302.04491v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.04491v1-abstract-full" style="display: none;"> Massive star feedback affects the evolution of galaxies, where the most massive stars may have the largest impact. The majority of massive stars are born as members of close binary systems. Here, we investigate detailed evolutionary models of very massive binaries (30$\dots$90$M_{\odot}$) with Large Magellanic Cloud (LMC) metallicity. We identify four effects defying the conventional knowledge of binary evolution, which are all related to the proximity of the models to the Eddington limit. We find that the majority of systems undergo mass transfer during core hydrogen burning. During the ensuing nuclear timescale evolution, many mass donors remain more massive than their companions (``reverse Algols''), and nuclear timescale mass transfer may be interrupted or absent altogether. Furthermore, due to the elevated luminosity-to-mass ratio, many of the core-hydrogen burning donors may develop Wolf-Rayet-type winds, at luminosities where single stars would not. We identify observational counterparts of very massive reverse Algol binaries in the LMC, and discuss their contribution to the observed hydrogen-rich Wolf-Rayet stars. We argue that an understanding of very massive Algol systems is key to predicting the advanced evolution of very massive binaries, including their ability to evolve into observable gravitational wave sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04491v1-abstract-full').style.display = 'none'; document.getElementById('2302.04491v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 5 figures, proposed for acceptance in A&A. Animation at https://zenodo.org/record/4068428#.Y-SrOtLMKV4</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 672, A198 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.03168">arXiv:2302.03168</a> <span> [<a href="https://arxiv.org/pdf/2302.03168">pdf</a>, <a href="https://arxiv.org/format/2302.03168">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202245364">10.1051/0004-6361/202245364 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multiplicity of northern bright O-type stars with optical long baseline interferometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lanthermann%2C+C">Cyprien Lanthermann</a>, <a href="/search/astro-ph?searchtype=author&query=Bouquin%2C+J+L">Jean-Baptiste Le Bouquin</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%A9rand%2C+A">Antoine M茅rand</a>, <a href="/search/astro-ph?searchtype=author&query=Monnier%2C+J+D">John D. Monnier</a>, <a href="/search/astro-ph?searchtype=author&query=Perraut%2C+K">Karine Perraut</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">Abigail J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Gosset%2C+E">Eric Gosset</a>, <a href="/search/astro-ph?searchtype=author&query=De+Becker%2C+M">Michael De Becker</a>, <a href="/search/astro-ph?searchtype=author&query=Kraus%2C+S">Stefan Kraus</a>, <a href="/search/astro-ph?searchtype=author&query=Anugu%2C+N">Narsireddy Anugu</a>, <a href="/search/astro-ph?searchtype=author&query=Davies%2C+C+L">Claire L. Davies</a>, <a href="/search/astro-ph?searchtype=author&query=Ennis%2C+J">Jacob Ennis</a>, <a href="/search/astro-ph?searchtype=author&query=Gardner%2C+T">Tyler Gardner</a>, <a href="/search/astro-ph?searchtype=author&query=Labdon%2C+A">Aaron Labdon</a>, <a href="/search/astro-ph?searchtype=author&query=Setterholm%2C+B">Benjamin Setterholm</a>, <a href="/search/astro-ph?searchtype=author&query=Brummelaar%2C+T+t">Theo ten Brummelaar</a>, <a href="/search/astro-ph?searchtype=author&query=Schaefer%2C+G+H">Gail H. Schaefer</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.03168v2-abstract-short" style="display: inline;"> The study of the multiplicity of massive stars gives hints on their formation processes and their evolutionary paths, which are still not fully understood. Large separation binaries (>50 milliseconds of arc, mas) can be probed by adaptive-optics-assisted direct imaging and sparse aperture masking, while close binaries can be resolved by photometry and spectroscopy. However, optical long baseline i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.03168v2-abstract-full').style.display = 'inline'; document.getElementById('2302.03168v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.03168v2-abstract-full" style="display: none;"> The study of the multiplicity of massive stars gives hints on their formation processes and their evolutionary paths, which are still not fully understood. Large separation binaries (>50 milliseconds of arc, mas) can be probed by adaptive-optics-assisted direct imaging and sparse aperture masking, while close binaries can be resolved by photometry and spectroscopy. However, optical long baseline interferometry is mandatory to establish the multiplicity of Galactic massive stars at the separation gap between 1 and 50 mas. In this paper, we aim to demonstrate the capability of the new interferometric instrument MIRC-X, located at the CHARA Array, to study the multiplicity of O-type stars and therefore probe the full range of separation for more than 120 massive stars (H<7.5 mag). We initiated a pilot survey of bright O-type stars (H<6.5mag) observable with MIRC-X. We observed 29 O-type stars, including two systems in average atmospheric conditions around a magnitude of H=7.5 mag. We systematically reduced the obtained data with the public reduction pipeline of the instrument. We analyzed the reduced data using the dedicated python software CANDID to detect companions. Out of these 29 systems, we resolved 19 companions in 17 different systems with angular separations between ~0.5 and 50 mas. This results in a multiplicity fraction fm=17/29=0.59+/-0.09, and an average number of companions fc=19/29=0.66+/-0.13. Those results are in agreement with the results of the SMASH+ survey in the Southern Hemisphere. Thirteen of these companions have been resolved for the first time, including the companion responsible for the nonthermal emission in Cyg OB2-5 A and the confirmation of the candidate companion of HD 47129 suggested by SMASH+. A large survey on more than 120 northern O-type stars (H<7.5) is possible with MIRC-X and will be fruitful. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.03168v2-abstract-full').style.display = 'none'; document.getElementById('2302.03168v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 9 figures, 5 tables, accepted in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 672, A6 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.06927">arXiv:2212.06927</a> <span> [<a href="https://arxiv.org/pdf/2212.06927">pdf</a>, <a href="https://arxiv.org/format/2212.06927">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244308">10.1051/0004-6361/202244308 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A spectroscopic multiplicity survey of Galactic Wolf-Rayet stars. III. The northern late-type nitrogen-rich sample </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2212.06927v1-abstract-short" style="display: inline;"> Massive stars are powerful cosmic engines. In the phases immediately preceding core-collapse, massive stars in the Galaxy with $M_i \gtrsim 20$ $M_{\odot}$ may appear as classical Wolf-Rayet (WR) stars. As the final contribution of a homogeneous RV survey, this work constrains the multiplicity properties of northern Galactic late-type nitrogen-rich Wolf-Rayet (WNL) stars. We compare their intrinsi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.06927v1-abstract-full').style.display = 'inline'; document.getElementById('2212.06927v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.06927v1-abstract-full" style="display: none;"> Massive stars are powerful cosmic engines. In the phases immediately preceding core-collapse, massive stars in the Galaxy with $M_i \gtrsim 20$ $M_{\odot}$ may appear as classical Wolf-Rayet (WR) stars. As the final contribution of a homogeneous RV survey, this work constrains the multiplicity properties of northern Galactic late-type nitrogen-rich Wolf-Rayet (WNL) stars. We compare their intrinsic binary fraction and orbital period distribution to the carbon-rich (WC) and early-type nitrogen-rich (WNE) populations from previous works. We obtained high-resolution spectra of the complete magnitude-limited sample of 11 Galactic WNL stars with the Mercator telescope on the island of La Palma. We used cross-correlation to measure relative RVs and flagged binary candidates based on the peak-to-peak RV dispersion. By using Monte Carlo sampling and a Bayesian framework, we computed the three-dimensional likelihood and one-dimensional posteriors for the upper period cut-off, power-law index, and intrinsic binary fraction. Adopting a threshold $C$ of 50 km s$^{-1}$, our Bayesian analysis produced an intrinsic fraction of $0.42\substack{+0.15 \\ -0.17}$ for the parent WNL population alongside distributions for the power-law index and the orbital periods. The observed period distribution of Galactic WN and WC binaries from the literature is in agreement with what is found. The period distribution of Galactic WN binaries peaks at $P{\sim}1$-$10$d and that of the WC population at $P{\sim}5000\,$d. This shift cannot be reconciled by orbital evolution due to mass loss or mass transfer. At long periods, the evolutionary sequence O($\xrightarrow{}$LBV)$\xrightarrow{}$WN$\xrightarrow{}$WC seems feasible. The high frequency of short-period WN binaries compared to WC binaries suggests that they either tend to merge or that the WN components in these binaries rarely evolve into WC stars in the Galaxy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.06927v1-abstract-full').style.display = 'none'; document.getElementById('2212.06927v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy and Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 674, A88 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.13476">arXiv:2211.13476</a> <span> [<a href="https://arxiv.org/pdf/2211.13476">pdf</a>, <a href="https://arxiv.org/format/2211.13476">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244677">10.1051/0004-6361/202244677 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The VLT-FLAMES Tarantula Survey: Observational evidence for two distinct populations of massive runaway stars in 30 Doradus </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Ram%C3%ADrez-Agudelo%2C+O+H">O. H. Ram铆rez-Agudelo</a>, <a href="/search/astro-ph?searchtype=author&query=H%C3%A9nault-Brunet%2C+V">V. H茅nault-Brunet</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Almeida%2C+L+A">L. A. Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Bestenlehner%2C+J+M">J. M. Bestenlehner</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+C+J">C. J. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+F+R+N">F. R. N. Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">P. A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=de+Mink%2C+S+E">S. E. de Mink</a>, <a href="/search/astro-ph?searchtype=author&query=Herrero%2C+A">A. Herrero</a>, <a href="/search/astro-ph?searchtype=author&query=Lennon%2C+D+J">D. J. Lennon</a>, <a href="/search/astro-ph?searchtype=author&query=Gieles%2C+M">M. Gieles</a>, <a href="/search/astro-ph?searchtype=author&query=Apell%C3%A1niz%2C+J+M">J. Ma铆z Apell谩niz</a>, <a href="/search/astro-ph?searchtype=author&query=Renzo%2C+M">M. Renzo</a>, <a href="/search/astro-ph?searchtype=author&query=Sabbi%2C+E">E. Sabbi</a>, <a href="/search/astro-ph?searchtype=author&query=van+Loon%2C+J+T">J. Th. van Loon</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">J. S. Vink</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.13476v1-abstract-short" style="display: inline;"> Two main scenarios have been proposed for origin of massive runaway stars -- dynamical ejection or release from a binary at the first core collapse -- but their relative contribution remains debated. Using two large spectroscopic campaigns towards massive stars in 30 Doradus, we aim to provide observational constraints on the properties of the O-type runaway population in the most massive active… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.13476v1-abstract-full').style.display = 'inline'; document.getElementById('2211.13476v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.13476v1-abstract-full" style="display: none;"> Two main scenarios have been proposed for origin of massive runaway stars -- dynamical ejection or release from a binary at the first core collapse -- but their relative contribution remains debated. Using two large spectroscopic campaigns towards massive stars in 30 Doradus, we aim to provide observational constraints on the properties of the O-type runaway population in the most massive active star-forming region in the Local group. We use RV measurements of the O-type star populations in 30 Doradus obtained by the VLT-FLAMES Tarantula Survey and the Tarantula Massive Binary Monitoring to identify single and binary O-type runaways. We discuss their rotational properties and qualitatively compare observations with expectations of ejection scenarios. We identify 23 single and one binary O-type runaway objects, most of them outside the main star-forming regions in 30 Doradus. We find an overabundance of rapid rotators (vsini > 200km/s) among the runaway population, providing an explanation of the overabundance of rapidly rotating stars in the 30 Doradus field. Considerations of the projected rotation rates and runaway line-of-sight (los) velocities reveal a conspicuous absence of rapidly rotating (vsini > 210k/ms), fast moving (v_{los} > 60km/s) runaways, and suggest the presence of two different populations of runaway stars: a population of rapidly-spinning but slowly moving runaways and a population of fast moving but slowly rotating ones. These are detected with a ratio close to 2:1 in our sample. We argue that slowly moving but rapidly spinning runaways result from binary ejections, while rapidly moving but slowly spinning runaways could result from dynamical ejections. Given that detection biases will more strongly impact the slow-moving population, our results suggest that the binary evolution scenario dominates the current massive runaway population in 30 Doradus. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.13476v1-abstract-full').style.display = 'none'; document.getElementById('2211.13476v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in A&A Letters; 9 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 668, L5 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.05680">arXiv:2211.05680</a> <span> [<a href="https://arxiv.org/pdf/2211.05680">pdf</a>, <a href="https://arxiv.org/format/2211.05680">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244818">10.1051/0004-6361/202244818 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detection of single-degenerate massive binaries with Gaia: The impact of blue supergiants, triples, mass precision, and high-precision parallax requirements </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Janssens%2C+S">S. Janssens</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.05680v1-abstract-short" style="display: inline;"> Hundreds of black holes with massive main-sequence companions (OB+BHs) might be identified from Gaia astrometry with the Astrometric Mass-Ratio Function (AMRF). We investigate the impact of blue supergiant companions (BSG) instead of dwarfs and the presence of additional companions in the system that are unresolved by Gaia on the astrometric identification of OB+BHs. We also explore how accurate t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.05680v1-abstract-full').style.display = 'inline'; document.getElementById('2211.05680v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.05680v1-abstract-full" style="display: none;"> Hundreds of black holes with massive main-sequence companions (OB+BHs) might be identified from Gaia astrometry with the Astrometric Mass-Ratio Function (AMRF). We investigate the impact of blue supergiant companions (BSG) instead of dwarfs and the presence of additional companions in the system that are unresolved by Gaia on the astrometric identification of OB+BHs. We also explore how accurate the primary mass needs to be constrained. Moreover, we assess how the high-precision publishing constraints of astrometric binary orbits in the latest Gaia data release DR3 impact the detection of OB+BHs. We establish a BSG mass-magnitude relation and compute BSG AMRF curves. From a mock population of non- and single-degenerate massive binaries and triples with OB or BSG primaries, we asses the false-positive identification fraction and the effect of the BSG AMRF curves. We compare the number of stars with astrometric DR3 orbits in the second Alma Luminous Star catalogue (ALSII) with new predictions on the OB+BH detection using the conservative DR3 publishing criteria. BSG primaries and triples are not expected to impact the false-positive identification fractions significantly. However, if the evolutionary stage of the primary star is unknown, the usage of the BSG curves is still recommended. This also reduces the OB+BH identification fraction significantly. The primary mass does not need to be known to benefit from the high identification fraction of OB+BHs, while keeping the fraction of false-positives low. We find no OB+BH candidates in the ALS II among the DR3 orbits. This null-detection cannot be attributed to the underlying BH-formation scenario, but rather to the stringent DR3 selection criteria. To infer the BH-formation scenario with Gaia, we propose that the constraint on the relative parallax precision in DR4 should be 95% less conservative than the DR3 criterion.(Abridged) <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.05680v1-abstract-full').style.display = 'none'; document.getElementById('2211.05680v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages (+ 5 appendix), 10 figures, 3 tables, submitted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 670, A79 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.07149">arXiv:2210.07149</a> <span> [<a href="https://arxiv.org/pdf/2210.07149">pdf</a>, <a href="https://arxiv.org/format/2210.07149">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244742">10.1051/0004-6361/202244742 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Searching for compact objects in the single-lined spectroscopic binaries of the young Galactic cluster NGC 6231 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">G. Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Villase%C5%84or%2C+J+I">J. I. Villase艅or</a>, <a href="/search/astro-ph?searchtype=author&query=Sen%2C+K">K. Sen</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=de+Mink%2C+S">S. de Mink</a>, <a href="/search/astro-ph?searchtype=author&query=Picco%2C+A">A. Picco</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.07149v1-abstract-short" style="display: inline;"> Recent evolutionary computations predict that a few percent of massive OB stars in binary systems should have a dormant BH companion. Despite several reported X-ray quiet OB+BH systems over the last couple of years, finding them with certainty remains challenging. These have great importance as they can be gravitational wave (GW) source progenitors, and are landmark systems in constraining superno… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.07149v1-abstract-full').style.display = 'inline'; document.getElementById('2210.07149v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.07149v1-abstract-full" style="display: none;"> Recent evolutionary computations predict that a few percent of massive OB stars in binary systems should have a dormant BH companion. Despite several reported X-ray quiet OB+BH systems over the last couple of years, finding them with certainty remains challenging. These have great importance as they can be gravitational wave (GW) source progenitors, and are landmark systems in constraining supernova kick physics. This work aims to characterise the hidden companions to the single-lined spectroscopic binaries (SB1s) in the B star population of the young open Galactic cluster NGC 6231 to find candidate systems for harbouring compact object companions. With the orbital solutions for each SB1 previously constrained, we applied Fourier spectral disentangling to multi-epoch optical VLT/FLAMES spectra of each target to extract a potential signature of a faint companion, and to identify newly disentangled double-lined spectroscopic binaries (SB2s). For targets where the disentangling does not reveal any signature of a stellar companion, we performed atmospheric and evolutionary modelling on the primary to obtain constraints on the unseen companion. Seven newly classified SB2 systems with mass ratios down to near 0.1 were identified. From the remaining targets, for which no faint companion could be extracted from the spectra, four are found to have companion masses in the predicted mass ranges of neutron stars (NSes) and BHes. Two of these have companion masses between 1 and 3.5 $M_{\odot}$, making them potential hosts of NSes (or lower mass main sequence stars). The other two are between 2.5 to 8 $M_{\odot}$ and 1.6 and 26 $M_{\odot}$, respectively, and so are identified as candidates for harbouring BH companions. However, unambiguous identification of these systems as X-ray quiet compact object harbouring binaries requires follow up observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.07149v1-abstract-full').style.display = 'none'; document.getElementById('2210.07149v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 674, A60 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.06491">arXiv:2210.06491</a> <span> [<a href="https://arxiv.org/pdf/2210.06491">pdf</a>, <a href="https://arxiv.org/format/2210.06491">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244808">10.1051/0004-6361/202244808 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Tidal perturbations and eclipse mapping in the pulsations in the hierarchical triple system U~Gru </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Johnston%2C+C">Cole Johnston</a>, <a href="/search/astro-ph?searchtype=author&query=Tkachenko%2C+A">Andrew Tkachenko</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Reeth%2C+T">Timothy Van Reeth</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">Dominic M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlovski%2C+K">Kresimir Pavlovski</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Sekaran%2C+S">Sanjay Sekaran</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.06491v1-abstract-short" style="display: inline;"> Context. Unambiguous examples of the influence of tides on self-excited, free stellar pulsations have recently been observationally detected in space-based photometric data. Aims. We aim to investigate U Gru and contextualise it within the growing class of tidally influenced pulsators. Initial analysis of U Gru revealed frequencies spaced by the orbital frequency that are difficult to explain by c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.06491v1-abstract-full').style.display = 'inline'; document.getElementById('2210.06491v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.06491v1-abstract-full" style="display: none;"> Context. Unambiguous examples of the influence of tides on self-excited, free stellar pulsations have recently been observationally detected in space-based photometric data. Aims. We aim to investigate U Gru and contextualise it within the growing class of tidally influenced pulsators. Initial analysis of U Gru revealed frequencies spaced by the orbital frequency that are difficult to explain by currently proposed tidal mechanisms. Methods. We re-investigate the TESS photometry of U Gru alongside new uves spectroscopy. We analyse the uves spectroscopy with least-squares deconvolution and spectral disentangling techniques, and perform an atmospheric analysis. We remove the binary signature from the light curve using an effective model in order to investigate the pulsation signal in the residuals. We track the amplitudes and phases of the residual pulsations as a function of the orbital period to reveal their tidal influence. Results. We establish that U Gru is likely a hierarchical triple system. We identify a single p mode oscillation to exhibit amplitude and phase variation over the binary orbit. We propose a toy model to demonstrate that the series of frequencies separated by the orbital frequency can be reproduced by eclipse mapping. We find no evidence of modulation to the other independent oscillation modes. Conclusions. We demonstrate that U Gru hosts at least one tidally perturbed pulsation. Additionally we argue that eclipse mapping of the dominant, tidally perturbed mode can produce the series of frequencies separated by the observed orbital frequency. Our simulations show that the effects of eclipse mapping are mode dependent, and are not expected to produce an observable signature for all pulsation modes in an eclipse binary. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.06491v1-abstract-full').style.display = 'none'; document.getElementById('2210.06491v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy & Astrophysics. 13 pages, 10 figures, 3 tables, 1 appendix</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 670, A167 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.06287">arXiv:2209.06287</a> <span> [<a href="https://arxiv.org/pdf/2209.06287">pdf</a>, <a href="https://arxiv.org/format/2209.06287">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The Nature of Unseen Companions in Massive Single-Line Spectroscopic Binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">Michael Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">Gareth Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">Julia Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">Dominic M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">Karan Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Eldridge%2C+C">C. Eldridge</a>, <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">Matthias Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">Abigail J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">Calum Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Janssens%2C+S">Soetkin Janssens</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">Norbert Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Reeth%2C+T">Timothy Van Reeth</a>, <a href="/search/astro-ph?searchtype=author&query=Sen%2C+K">Koushik Sen</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">Tomer Shenar</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2209.06287v1-abstract-short" style="display: inline;"> Massive stars are predominantly found in binaries and higher order multiples. While the period and eccentricity distributions of OB stars are now well established across different metallicity regimes, the determination of mass-ratios has been mostly limited to double-lined spectroscopic binaries. As a consequence, the mass-ratio distribution remains subject to significant uncertainties. Open quest… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.06287v1-abstract-full').style.display = 'inline'; document.getElementById('2209.06287v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.06287v1-abstract-full" style="display: none;"> Massive stars are predominantly found in binaries and higher order multiples. While the period and eccentricity distributions of OB stars are now well established across different metallicity regimes, the determination of mass-ratios has been mostly limited to double-lined spectroscopic binaries. As a consequence, the mass-ratio distribution remains subject to significant uncertainties. Open questions include the shape and extent of the companion mass-function towards its low-mass end and the nature of undetected companions in single-lined spectroscopic binaries. In this contribution, we present the results of a large and systematic analysis of a sample of over 80 single-lined O-type spectroscopic binaries (SB1s) in the Milky Way and in the Large Magellanic Cloud (LMC). We report on the developed methodology, the constraints obtained on the nature of SB1 companions, the distribution of O star mass-ratios at LMC metallicity and the occurrence of quiescent OB+black hole binaries. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.06287v1-abstract-full').style.display = 'none'; document.getElementById('2209.06287v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">To appear in the proceedings of IAUS361: Massive stars near and far; 6 pages, 1 figure</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.01533">arXiv:2208.01533</a> <span> [<a href="https://arxiv.org/pdf/2208.01533">pdf</a>, <a href="https://arxiv.org/format/2208.01533">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1017/S174392132200326X">10.1017/S174392132200326X <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The CubeSpec space mission: Asteroseismology of massive stars from time-series optical spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Vandenbussche%2C+B">B. Vandenbussche</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Tkachenko%2C+A">A. Tkachenko</a>, <a href="/search/astro-ph?searchtype=author&query=Raskin%2C+G">G. Raskin</a>, <a href="/search/astro-ph?searchtype=author&query=Delabie%2C+T">T. Delabie</a>, <a href="/search/astro-ph?searchtype=author&query=Vandoren%2C+B">B. Vandoren</a>, <a href="/search/astro-ph?searchtype=author&query=Royer%2C+P">P. Royer</a>, <a href="/search/astro-ph?searchtype=author&query=Garcia%2C+S">S. Garcia</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Reeth%2C+T">T. Van Reeth</a>, <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+t+C">the CubeSpec Collaboration</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.01533v1-abstract-short" style="display: inline;"> The ESA/KU Leuven CubeSpec mission is specifically designed to provide low-cost space-based high-resolution optical spectroscopy. Here we highlight the science requirements and capabilities of CubeSpec. The primary science goal is to perform pulsation mode identification from spectroscopic line profile variability and empower asteroseismology of massive stars. </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.01533v1-abstract-full" style="display: none;"> The ESA/KU Leuven CubeSpec mission is specifically designed to provide low-cost space-based high-resolution optical spectroscopy. Here we highlight the science requirements and capabilities of CubeSpec. The primary science goal is to perform pulsation mode identification from spectroscopic line profile variability and empower asteroseismology of massive stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01533v1-abstract-full').style.display = 'none'; document.getElementById('2208.01533v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Authors' submitted version of poster proceedings paper for IAU Symposium 361: Massive Stars Near and Far, held in Ballyconnell, Ireland, 9-13 May 2022</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Proc. IAU 18 (2022) 630-632 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.07752">arXiv:2207.07752</a> <span> [<a href="https://arxiv.org/pdf/2207.07752">pdf</a>, <a href="https://arxiv.org/format/2207.07752">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202243147">10.1051/0004-6361/202243147 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Identifying quiescent compact objects in massive Galactic single-lined spectroscopic binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sen%2C+K">K. Sen</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">N. Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">G. Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">M. Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Janssens%2C+S">S. Janssens</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Reeth%2C+T">T. Van Reeth</a>, <a href="/search/astro-ph?searchtype=author&query=Eldridge%2C+C">C. Eldridge</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.07752v1-abstract-short" style="display: inline;"> Aims. To search for these rare objects, we study 32 Galactic O-type stars that were reported as SB1s in the literature. In our sample we include Cyg X-1, which is known to host an accreting stellar-mass BH, and HD 74194, a supergiant fast X-ray transient, in order to validate our methodology. The final goal is to characterise the nature of the unseen companions to determine if they are MS stars, s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07752v1-abstract-full').style.display = 'inline'; document.getElementById('2207.07752v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.07752v1-abstract-full" style="display: none;"> Aims. To search for these rare objects, we study 32 Galactic O-type stars that were reported as SB1s in the literature. In our sample we include Cyg X-1, which is known to host an accreting stellar-mass BH, and HD 74194, a supergiant fast X-ray transient, in order to validate our methodology. The final goal is to characterise the nature of the unseen companions to determine if they are MS stars, stripped helium stars, triples, or compact objects such as neutron stars or stellar-mass BHs. Methods. After measuring radial velocities and deriving orbital solutions for all the systems in our sample, we performed spectral disentangling to extract putative signatures of faint secondary companions from the composite spectra. We derived stellar parameters for the visible stars and estimated the mass ranges of the secondary stars using the binary mass function. Variability observed in the photometric TESS light curves was also searched for indications of the presence of putative companions, degenerate or not. Results. In 17 of the 32 systems reported as SB1s, we extract secondary signatures, down to mass ratios of ~0.15. For the 17 newly detected double-lined spectroscopic binaries (SB2s), we derive physical properties of the individual components and discuss why they have not been detected as such before. Among the remaining systems, we identify nine systems with possible NS or low-mass MS companions. For Cyg X-1 and HD 130298, we are not able to extract any signatures for the companions, and the minimum masses of their companions are estimated to be about 7Msun. Our simulations show that secondaries with such a mass should be detectable from our dataset, no matter their nature: MS stars, stripped helium stars or even triples. While this is expected for Cyg X-1, confirming our methodology, our simulations also strongly suggest that HD 130298 could be another candidate to host a stellar-mass BH. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07752v1-abstract-full').style.display = 'none'; document.getElementById('2207.07752v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages (31 pages of Appendix), 19 figures, A&A in press. The abstract is shorter than in the paper, and some figures, and tables have been cut in the paper</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.07675">arXiv:2207.07675</a> <span> [<a href="https://arxiv.org/pdf/2207.07675">pdf</a>, <a href="https://arxiv.org/format/2207.07675">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41550-022-01730-y">10.1038/s41550-022-01730-y <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An X-ray quiet black hole born with a negligible kick in a massive binary within the Large Magellanic Cloud </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">Tomer Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=El-Badry%2C+K">Kareem El-Badry</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">Norbert Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">Calum Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">Matthias Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Sen%2C+K">Koushik Sen</a>, <a href="/search/astro-ph?searchtype=author&query=Almeida%2C+L+A">Leonardo A. Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">Michael Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">Julia Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">Paul A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Gieles%2C+M">Mark Gieles</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">Mariusz Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Henault-Brunet%2C+V">Vincent Henault-Brunet</a>, <a href="/search/astro-ph?searchtype=author&query=Herrero%2C+A">Artemio Herrero</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">Alex de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Iwanek%2C+P">Patryk Iwanek</a>, <a href="/search/astro-ph?searchtype=author&query=Koz%C5%82owski%2C+S">Szymon Koz艂owski</a>, <a href="/search/astro-ph?searchtype=author&query=Lennon%2C+D+J">Daniel J. Lennon</a>, <a href="/search/astro-ph?searchtype=author&query=Apellaniz%2C+J+M">Jesus Ma谋z Apellaniz</a>, <a href="/search/astro-ph?searchtype=author&query=Mroz%2C+P">Przemys艂aw Mroz</a>, <a href="/search/astro-ph?searchtype=author&query=Moffat%2C+A+F+J">Anthony F. J. Moffat</a>, <a href="/search/astro-ph?searchtype=author&query=Picco%2C+A">Annachiara Picco</a> , et al. (13 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.07675v1-abstract-short" style="display: inline;"> Stellar-mass black holes are the final remnants of stars born with more than 15 solar masses. Billions are expected to reside in the Local Group, yet only few are known, mostly detected through X-rays emitted as they accrete material from a companion star. Here, we report on VFTS 243: a massive X-ray faint binary in the Large Magellanic Cloud. With an orbital period of 10.4-d, it comprises an O-ty… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07675v1-abstract-full').style.display = 'inline'; document.getElementById('2207.07675v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.07675v1-abstract-full" style="display: none;"> Stellar-mass black holes are the final remnants of stars born with more than 15 solar masses. Billions are expected to reside in the Local Group, yet only few are known, mostly detected through X-rays emitted as they accrete material from a companion star. Here, we report on VFTS 243: a massive X-ray faint binary in the Large Magellanic Cloud. With an orbital period of 10.4-d, it comprises an O-type star of 25 solar masses and an unseen companion of at least nine solar masses. Our spectral analysis excludes a non-degenerate companion at a 5-sigma confidence level. The minimum companion mass implies that it is a black hole. No other X-ray quiet black hole is unambiguously known outside our Galaxy. The (near-)circular orbit and kinematics of VFTS 243 imply that the collapse of the progenitor into a black hole was associated with little or no ejected material or black-hole kick. Identifying such unique binaries substantially impacts the predicted rates of gravitational-wave detections and properties of core-collapse supernovae across the Cosmos. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07675v1-abstract-full').style.display = 'none'; document.getElementById('2207.07675v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to Nature Astronomy, 64 pages, 15 figures, 2 tables; ESO press release: https://www.eso.org/public/news/eso2210/; Nat Asr paper URL: https://www.nature.com/articles/s41550-022-01730-y</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.07674">arXiv:2207.07674</a> <span> [<a href="https://arxiv.org/pdf/2207.07674">pdf</a>, <a href="https://arxiv.org/format/2207.07674">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244245">10.1051/0004-6361/202244245 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Tarantula Massive Binary Monitoring VI: Characterisation of hidden companions in 51 single-lined O-type binaries, a flat mass-ratio distribution, and black-hole binary candidates </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">Tomer Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">Laurent Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Apellaniz%2C+J+M">Jesus Maiz Apellaniz</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">Paul A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">Mariusz Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Herrero%2C+A">Artemio Herrero</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">Norbert Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">Pablo Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+F+R+N">Fabian R. N. Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Sen%2C+K">Koushik Sen</a>, <a href="/search/astro-ph?searchtype=author&query=Soszynski%2C+I">Igor Soszynski</a>, <a href="/search/astro-ph?searchtype=author&query=Toonen%2C+S">S. Toonen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.07674v2-abstract-short" style="display: inline;"> We aim to hunt for massive binaries hosting a black hole companion (OB+BH) and establish the natal mass-ratio distribution of massive stars at the subsolar metallicity environment of the Large Magellanic Cloud (LMC). We use the shift-and-add grid disentangling technique to characterize the hidden companions in 51 SB1 O-type and evolved B-type binaries in the LMC monitored in the framework of the T… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07674v2-abstract-full').style.display = 'inline'; document.getElementById('2207.07674v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.07674v2-abstract-full" style="display: none;"> We aim to hunt for massive binaries hosting a black hole companion (OB+BH) and establish the natal mass-ratio distribution of massive stars at the subsolar metallicity environment of the Large Magellanic Cloud (LMC). We use the shift-and-add grid disentangling technique to characterize the hidden companions in 51 SB1 O-type and evolved B-type binaries in the LMC monitored in the framework of the Tarantula Massive Binary Monitoring (TMBM). Out of the 51 SB1 systems, 43 (84%) are found to have non-degenerate stellar companions, of which 28 are confident detections, and 15 are less certain (SB1: or SB2:). Of these 43 targets, one is found to be a triple (VFTS 64), and two are found to be quadruples (VFTS 120, 702). The remaining eight targets (16%) retain an SB1 classification. Aside from the unambiguous case of VFTS 243, analysed in detailed in a separate paper, we identify two additional OB+BH candidates: VFTS 514 and VFTS 779. Additional black holes may be present in the sample but at a lower probability. Our study firmly establishes a virtually flat natal mass-ratio distribution for O-type stars at LMC metallicity, covering the entire mass-ratio range (0.05 < q < 1) and periods in the range 0 < log P < 3 [d]. The nature of the OB+BH candidates should be verified through future monitoring, but the frequency of OB+BH candidates is generally in line with recent predictions at LMC metallicity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07674v2-abstract-full').style.display = 'none'; document.getElementById('2207.07674v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">41 pages (14 main article + 27 appendix), accepted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 665, A148 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.00366">arXiv:2207.00366</a> <span> [<a href="https://arxiv.org/pdf/2207.00366">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.18727/0722-6691/5255">10.18727/0722-6691/5255 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detecting Stripped Stars While Searching for Quiescent Black Holes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Heida%2C+M">M. Heida</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">G. Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/astro-ph?searchtype=author&query=Fabry%2C+M">M. Fabry</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A">A. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%A9rand%2C+A">A. M茅rand</a>, <a href="/search/astro-ph?searchtype=author&query=Reggiani%2C+M">M. Reggiani</a>, <a href="/search/astro-ph?searchtype=author&query=Rivinius%2C+T">Th. Rivinius</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Selman%2C+F">F. Selman</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.00366v1-abstract-short" style="display: inline;"> While the number of stellar-mass black holes detected in X-rays or as gravitational wave sources is steadily increasing, the known population remains orders of magnitude smaller than predicted by stellar evolution theory. A significant fraction of stellar-mass black holes is expected to hide in X-ray-quiet binaries where they are paired with a "normal" star. Although a handful of such quiescent bl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.00366v1-abstract-full').style.display = 'inline'; document.getElementById('2207.00366v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.00366v1-abstract-full" style="display: none;"> While the number of stellar-mass black holes detected in X-rays or as gravitational wave sources is steadily increasing, the known population remains orders of magnitude smaller than predicted by stellar evolution theory. A significant fraction of stellar-mass black holes is expected to hide in X-ray-quiet binaries where they are paired with a "normal" star. Although a handful of such quiescent black hole candidates have been proposed, the majority have been challenged by follow-up investigations. A confusion that emerged recently concerns binary systems that appear to contain a normal B-type star with an unseen companion, believed to be a black hole. On closer inspection, some of these seemingly normal B-type stars instead turn out to be stars stripped of most of their mass through an interaction with their binary companion, which in at least two cases is a rapidly rotating star rather than a compact object. These contaminants in the search for quiescent black holes are themselves extremely interesting objects as they represent a rare phase of binary evolution, and should be given special attention when searching for binaries hosting black holes in large spectroscopic studies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.00366v1-abstract-full').style.display = 'none'; document.getElementById('2207.00366v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Messenger, 2022, vol. 186, p. 3-9 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.12518">arXiv:2204.12518</a> <span> [<a href="https://arxiv.org/pdf/2204.12518">pdf</a>, <a href="https://arxiv.org/format/2204.12518">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142729">10.1051/0004-6361/202142729 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A spectroscopic multiplicity survey of Galactic Wolf-Rayet stars: II. The northern WNE sequence </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Marchant%2C+P">P. Marchant</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.12518v1-abstract-short" style="display: inline;"> Most massive stars reside in multiple systems that will interact over the course of their lifetime. Classical Wolf-Rayet (WR) stars represent the final end stages of stellar evolution at the upper-mass end. As part of a homogeneous, magnitude-limited ($V\leq12$) spectroscopic survey of northern Galactic WR stars, this paper aims to establish the observed and intrinsic multiplicity properties of th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.12518v1-abstract-full').style.display = 'inline'; document.getElementById('2204.12518v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.12518v1-abstract-full" style="display: none;"> Most massive stars reside in multiple systems that will interact over the course of their lifetime. Classical Wolf-Rayet (WR) stars represent the final end stages of stellar evolution at the upper-mass end. As part of a homogeneous, magnitude-limited ($V\leq12$) spectroscopic survey of northern Galactic WR stars, this paper aims to establish the observed and intrinsic multiplicity properties of the early-type nitrogen-rich WR population (WNE). We obtained high-resolution spectroscopic time series of the complete magnitude-limited sample of 16 WNE stars observable with the 1.2 m Mercator telescope at La Palma, typically providing a time base of about two to eight years. We measured relative radial velocities (RVs) using cross-correlation and used RV variations to flag binary candidates. Adopting a peak-to-peak RV variability threshold of 50 km/s as a criterion found an observed multiplicity fraction of 0.44$\pm$0.12. Using an updated Monte Carlo method with a Bayesian framework, we calculated the three-dimensional likelihood for the intrinsic binary fraction, the maximum period, and the power-law index for the period distribution for the WNE population. We also re-derived multiplicity parameters for the Galactic WC population. We found an intrinsic multiplicity fraction of $0.56\substack{+0.20 \\ -0.15}$ for the parent WNE population. For the Galactic WC population, we re-derive an intrinsic multiplicity fraction of $0.96\substack{+0.04 \\ -0.22}$. The derived multiplicity parameters for the WNE population are quite similar to those derived for main-sequence O binaries but differ from those of the WC population. The significant shift in the WC period distribution towards longer periods is too large to be explained via expansion of the orbit due to stellar winds, and we discuss possible implications of our results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.12518v1-abstract-full').style.display = 'none'; document.getElementById('2204.12518v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 12 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 664, A93 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.09981">arXiv:2204.09981</a> <span> [<a href="https://arxiv.org/pdf/2204.09981">pdf</a>, <a href="https://arxiv.org/ps/2204.09981">ps</a>, <a href="https://arxiv.org/format/2204.09981">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142888">10.1051/0004-6361/202142888 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Method and new tabulations for flux-weighted line-opacity and radiation line-force in supersonic media </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Poniatowski%2C+L+G">L. G. Poniatowski</a>, <a href="/search/astro-ph?searchtype=author&query=Kee%2C+N+D">N. D. Kee</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J+O">J. O. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Driessen%2C+F+A">F. A. Driessen</a>, <a href="/search/astro-ph?searchtype=author&query=Moens%2C+N">N. Moens</a>, <a href="/search/astro-ph?searchtype=author&query=Owocki%2C+S+P">S. P. Owocki</a>, <a href="/search/astro-ph?searchtype=author&query=Gayley%2C+K+G">K. G. Gayley</a>, <a href="/search/astro-ph?searchtype=author&query=Decin%2C+L">L. Decin</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">A. de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.09981v1-abstract-short" style="display: inline;"> In accelerating and supersonic media, the interaction of photons with spectral lines can be of ultimate importance. However, fully accounting for such line forces currently can only be done by specialised codes in 1-D steady-state flows. More general cases and higher dimensions require alternative approaches. We presented a comprehensive and fast method for computing the radiation line-force using… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.09981v1-abstract-full').style.display = 'inline'; document.getElementById('2204.09981v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.09981v1-abstract-full" style="display: none;"> In accelerating and supersonic media, the interaction of photons with spectral lines can be of ultimate importance. However, fully accounting for such line forces currently can only be done by specialised codes in 1-D steady-state flows. More general cases and higher dimensions require alternative approaches. We presented a comprehensive and fast method for computing the radiation line-force using tables of spectral line-strength distribution parameters, which can be applied in arbitrary (multi-D, time-dependent) simulations, including those accounting for the line-deshadowing instability, to compute the appropriate opacities. We assumed local thermodynamic equilibrium to compute a flux-weighted line opacity from $>4$ million spectral lines. We derived the spectral line strength and tabulated the corresponding line-distribution parameters for a range of input densities $蟻\in[10^{-20},10^{-10}]gcm^{-3}$ and temperatures $T\in[10^4,10^{4.7}]K$. We found that the variation of the line distribution parameters plays an essential role in setting the wind dynamics in our models. In our benchmark study, we also found a good overall agreement between the O-star mass-loss rates of our models and those derived from steady-state studies using more detailed radiative transfer. Our models reinforce that self-consistent variation of the line-distribution parameters is important for the dynamics of line-driven flows. Within a well-calibrated O-star regime, our results support the proposed methodology. In practice, utilising the provided tables, yielded a factor $>100$ speed-up in computational time compared to specialised 1-D model-atmosphere codes of line-driven winds, which constitutes an important step towards efficient multi-D simulations. We conclude that our method and tables are ready to be exploited in various radiation-hydrodynamic simulations where the line force is important. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.09981v1-abstract-full').style.display = 'none'; document.getElementById('2204.09981v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 667, A113 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.16332">arXiv:2203.16332</a> <span> [<a href="https://arxiv.org/pdf/2203.16332">pdf</a>, <a href="https://arxiv.org/format/2203.16332">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1017/S1743921322001090">10.1017/S1743921322001090 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The interplay between mass-loss and binarity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.16332v2-abstract-short" style="display: inline;"> Most stars with birth masses larger than that of our Sun belong to binary or higher order multiple systems. Similarly, most stars have stellar winds. Radiation pressure and multiplicity create outflows of material that remove mass from the primary star and inject it into the interstellar medium or transfer it to a companion. Both have strong impact on the subsequent evolution of the stars, yet the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.16332v2-abstract-full').style.display = 'inline'; document.getElementById('2203.16332v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.16332v2-abstract-full" style="display: none;"> Most stars with birth masses larger than that of our Sun belong to binary or higher order multiple systems. Similarly, most stars have stellar winds. Radiation pressure and multiplicity create outflows of material that remove mass from the primary star and inject it into the interstellar medium or transfer it to a companion. Both have strong impact on the subsequent evolution of the stars, yet they are often studied separately. In this short review, I will sketch part of the landscape of the interplay between stellar winds and binarity. I will present several examples where binarity shapes the stellar outflows, providing new opportunities to understand and measure mass loss properties. Stellar winds spectral signatures often help clearly identifying key stages of stellar evolution. The multiplicity properties of these stages then shed a new light onto evolutionary connections between the different categories of evolved stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.16332v2-abstract-full').style.display = 'none'; document.getElementById('2203.16332v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Proceedings of IAU Symposium 366, 2022 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.05036">arXiv:2203.05036</a> <span> [<a href="https://arxiv.org/pdf/2203.05036">pdf</a>, <a href="https://arxiv.org/format/2203.05036">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202141849">10.1051/0004-6361/202141849 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the origin of close massive binaries in the M17 star-forming region </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bordier%2C+E">E. Bordier</a>, <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">A. J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Reggiani%2C+M">M. Reggiani</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%A9rand%2C+A">A. M茅rand</a>, <a href="/search/astro-ph?searchtype=author&query=Rainot%2C+A">A. Rainot</a>, <a href="/search/astro-ph?searchtype=author&query=Ram%C3%ADrez-Tannus%2C+M+C">M. C. Ram铆rez-Tannus</a>, <a href="/search/astro-ph?searchtype=author&query=de+Wit%2C+W+J">W. J. de Wit</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.05036v1-abstract-short" style="display: inline;"> Spectroscopic multiplicity surveys of O stars in young clusters and OB associations have revealed that a large portion ($\sim$ 70%) of these massive stars (M$_{i}$ $\gt$ 15 $M_{\odot}$) belong to close and short-period binaries (physical separation d $\lt$few au). Despite the recent and significant progress, the formation mechanisms leading to such close massive multiple systems remain to be eluci… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.05036v1-abstract-full').style.display = 'inline'; document.getElementById('2203.05036v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.05036v1-abstract-full" style="display: none;"> Spectroscopic multiplicity surveys of O stars in young clusters and OB associations have revealed that a large portion ($\sim$ 70%) of these massive stars (M$_{i}$ $\gt$ 15 $M_{\odot}$) belong to close and short-period binaries (physical separation d $\lt$few au). Despite the recent and significant progress, the formation mechanisms leading to such close massive multiple systems remain to be elucidated. As a result, young massive close binaries (or higher-order multiple systems) are unique laboratories to figure out the pairing mechanism of high-mass stars. We present the first VLTI/GRAVITY observations of six young O stars in the M17 star-forming region ($\lesssim$ 1 Myr) and two additional foreground stars. From the interferometric model fitting of visibility amplitudes and closure phases, we search for companions and measure their positions and flux ratios. Combining the resulting magnitude difference with atmosphere models and evolutionary tracks, we further constrain the masses of the individual components. All of the six high-mass stars are in multiple systems, leading to a multiplicity fraction (MF) of 100%, yielding a 68% confidence interval of 94-100%. We detect a total number of 9 companions with separations up to 120 au. Including previously identified spectroscopic companions, the companion fraction of the young O stars in our sample reaches 2.3$\pm$0.6. The derived masses span a wide range from 2.5 to 50 $M_{\odot}$, with a great tendency towards high-mass companions. While based on a modest sample, our results clearly indicate that the origin of the high degree of multiplicity is rooted in their star formation mechanism. No clear evidence for one of the competing concepts of massive star formation (core accretion or competitive accretion) could be found. However, our results are compatible with migration as a scenario for the formation of close massive binaries. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.05036v1-abstract-full').style.display = 'none'; document.getElementById('2203.05036v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 14 figures, 4 tables, 3 appendices</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 663, A26 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.02440">arXiv:2203.02440</a> <span> [<a href="https://arxiv.org/pdf/2203.02440">pdf</a>, <a href="https://arxiv.org/format/2203.02440">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac630">10.1093/mnras/stac630 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Properties of the Be-type stars in 30 Doradus </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Dufton%2C+P+L">P. L. Dufton</a>, <a href="/search/astro-ph?searchtype=author&query=Lennon%2C+D+J">D. J. Lennon</a>, <a href="/search/astro-ph?searchtype=author&query=Villasenor%2C+J+I">J. I. Villasenor</a>, <a href="/search/astro-ph?searchtype=author&query=Howarth%2C+I+D">I. D. Howarth</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+C+J">C. J. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=de+Mink%2C+S+E">S. E. de Mink</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Taylor%2C+W+D">W. D. Taylor</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.02440v2-abstract-short" style="display: inline;"> The evolutionary status of Be-type stars remains unclear, with both single-star and binary pathways having been proposed. Here, VFTS spectroscopy of 73 Be-type stars, in the spectral-type range, B0--B3, is analysed to estimate projected rotational velocities, radial velocities and stellar parameters. They are found to be rotating faster than the corresponding VFTS B-type sample but simulations imp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.02440v2-abstract-full').style.display = 'inline'; document.getElementById('2203.02440v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.02440v2-abstract-full" style="display: none;"> The evolutionary status of Be-type stars remains unclear, with both single-star and binary pathways having been proposed. Here, VFTS spectroscopy of 73 Be-type stars, in the spectral-type range, B0--B3, is analysed to estimate projected rotational velocities, radial velocities and stellar parameters. They are found to be rotating faster than the corresponding VFTS B-type sample but simulations imply that their projected rotational velocities are inconsistent with them all rotating at near critical velocities. The de-convolution of the projected rotational velocities estimates leads to a mean rotational velocity estimate of 320-350 km/s, approximately 100 km/s larger than that for the corresponding B-type sample. There is a dearth of targets with rotational velocities less than 0.4 of the critical velocity, with a broad distribution reaching up to critical rotation. Our best estimate for the mean or median of the rotational velocitiy is 0.68 of the critical velocity. Rapidly-rotating B-type stars are more numerous than their Be-type counterparts, whilst the observed frequency of Be-type stars identified as binary systems is significantly lower than that for normal B-type stars, consistent with their respective radial-velocity dispersions. The semi-amplitudes for the Be-type binaries are also smaller. Similar results are found for a SMC Be-type sample centred on NGC346 with no significant differences being found between the two samples. These results are compared with the predictions of single and binary stellar evolutionary models for Be-type stars. Assuming that a single mechanism dominated the production of classical Be-type stars, our comparison would favour a binary evolutionary history. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.02440v2-abstract-full').style.display = 'none'; document.getElementById('2203.02440v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS, Appendicesand Tables 2 and 4 published as supplementary material</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.01359">arXiv:2203.01359</a> <span> [<a href="https://arxiv.org/pdf/2203.01359">pdf</a>, <a href="https://arxiv.org/format/2203.01359">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202143004">10.1051/0004-6361/202143004 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> HR 6819 is a binary system with no black hole -- revisiting the source with infrared interferometry and optical integral field spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Frost%2C+A+J">A. J. Frost</a>, <a href="/search/astro-ph?searchtype=author&query=Bodensteiner%2C+J">J. Bodensteiner</a>, <a href="/search/astro-ph?searchtype=author&query=Rivinius%2C+T">Th. Rivinius</a>, <a href="/search/astro-ph?searchtype=author&query=Baade%2C+D">D. Baade</a>, <a href="/search/astro-ph?searchtype=author&query=Merand%2C+A">A. Merand</a>, <a href="/search/astro-ph?searchtype=author&query=Selman%2C+F">F. Selman</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">M. Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Banyard%2C+G">G. Banyard</a>, <a href="/search/astro-ph?searchtype=author&query=Bordier%2C+E">E. Bordier</a>, <a href="/search/astro-ph?searchtype=author&query=Dsilva%2C+K">K. Dsilva</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">C. Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Mahy%2C+L">L. Mahy</a>, <a href="/search/astro-ph?searchtype=author&query=Reggiani%2C+M">M. Reggiani</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">T. Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Cabezas%2C+M">M. Cabezas</a>, <a href="/search/astro-ph?searchtype=author&query=Hadrava%2C+P">P. Hadrava</a>, <a href="/search/astro-ph?searchtype=author&query=Heida%2C+M">M. Heida</a>, <a href="/search/astro-ph?searchtype=author&query=Klement%2C+R">R. Klement</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">H. Sana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.01359v1-abstract-short" style="display: inline;"> Two scenarios have been proposed to match the existing observational constraints of the object HR 6819. The system could consist of a close inner B-type giant plus a black hole (BH) binary with an additional Be companion in a wide orbit. Alternatively, it could be a binary composed of a stripped B star and a Be star in a close orbit. Either scenario makes HR 6819 a cornerstone object as the stella… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.01359v1-abstract-full').style.display = 'inline'; document.getElementById('2203.01359v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.01359v1-abstract-full" style="display: none;"> Two scenarios have been proposed to match the existing observational constraints of the object HR 6819. The system could consist of a close inner B-type giant plus a black hole (BH) binary with an additional Be companion in a wide orbit. Alternatively, it could be a binary composed of a stripped B star and a Be star in a close orbit. Either scenario makes HR 6819 a cornerstone object as the stellar BH closest to Earth, or as an example of an important transitional, non-equilibrium phase for Be stars with solid evidence for its nature. We aimed to distinguish between the two scenarios for HR 6819. Both models predict two luminous stars but with very different angular separations and orbital motions. Therefore, the presence of bright sources in the 1-100 milliarcsec (mas) regime is a key diagnostic for determining the nature of the HR 6819 system. We obtained new high-angular resolution data with VLT/MUSE and VLTI/GRAVITY of HR 6819. The MUSE data are sensitive to bright companions at large scales, whilst the interferometric GRAVITY data are sensitive down to separations on mas scales and large magnitude differences. The MUSE observations reveal no bright companion at large separations and the GRAVITY observations indicate the presence of a stellar companion at an angular separation of ~1.2 mas that moves on the plane of the sky over a timescale compatible with the known spectroscopic 40-day period. We conclude that HR 6819 is a binary system and that no BH is present in the system. The unique nature of HR 6819, and its proximity to Earth make it an ideal system for quantitatively characterising the immediate outcome of binary interaction and probing how Be stars form. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.01359v1-abstract-full').style.display = 'none'; document.getElementById('2203.01359v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 11 figures, subject of ESO press release eso2204</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, Volume 659, March 2022, L3, 12, Letters to the Editor </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.11080">arXiv:2202.11080</a> <span> [<a href="https://arxiv.org/pdf/2202.11080">pdf</a>, <a href="https://arxiv.org/format/2202.11080">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142742">10.1051/0004-6361/202142742 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The R136 star cluster dissected with Hubble Space Telescope/STIS. III. The most massive stars and their clumped winds </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Brands%2C+S+A">Sarah A. Brands</a>, <a href="/search/astro-ph?searchtype=author&query=de+Koter%2C+A">Alex de Koter</a>, <a href="/search/astro-ph?searchtype=author&query=Bestenlehner%2C+J+M">Joachim M. Bestenlehner</a>, <a href="/search/astro-ph?searchtype=author&query=Crowther%2C+P+A">Paul A. Crowther</a>, <a href="/search/astro-ph?searchtype=author&query=Sundqvist%2C+J+O">Jon O. Sundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Puls%2C+J">Joachim Puls</a>, <a href="/search/astro-ph?searchtype=author&query=Caballero-Nieves%2C+S+M">Saida M. Caballero-Nieves</a>, <a href="/search/astro-ph?searchtype=author&query=Abdul-Masih%2C+M">Michael Abdul-Masih</a>, <a href="/search/astro-ph?searchtype=author&query=Driessen%2C+F+A">Florian A. Driessen</a>, <a href="/search/astro-ph?searchtype=author&query=Garc%C3%ADa%2C+M">Miriam Garc铆a</a>, <a href="/search/astro-ph?searchtype=author&query=Geen%2C+S">Sam Geen</a>, <a href="/search/astro-ph?searchtype=author&query=Gr%C3%A4fener%2C+G">G枚tz Gr盲fener</a>, <a href="/search/astro-ph?searchtype=author&query=Hawcroft%2C+C">Calum Hawcroft</a>, <a href="/search/astro-ph?searchtype=author&query=Kaper%2C+L">Lex Kaper</a>, <a href="/search/astro-ph?searchtype=author&query=Keszthelyi%2C+Z">Zsolt Keszthelyi</a>, <a href="/search/astro-ph?searchtype=author&query=Langer%2C+N">Norbert Langer</a>, <a href="/search/astro-ph?searchtype=author&query=Sana%2C+H">Hugues Sana</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+F+R+N">Fabian R. N. Schneider</a>, <a href="/search/astro-ph?searchtype=author&query=Shenar%2C+T">Tomer Shenar</a>, <a href="/search/astro-ph?searchtype=author&query=Vink%2C+J+S">Jorick S. Vink</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2202.11080v1-abstract-short" style="display: inline;"> Context: The star cluster R136 inside the LMC hosts a rich population of massive stars, including the most massive stars known. The strong stellar winds of these very luminous stars impact their evolution and the surrounding environment. We currently lack detailed knowledge of the wind structure that is needed to quantify this impact. Aims: To observationally constrain the stellar and wind propert… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.11080v1-abstract-full').style.display = 'inline'; document.getElementById('2202.11080v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.11080v1-abstract-full" style="display: none;"> Context: The star cluster R136 inside the LMC hosts a rich population of massive stars, including the most massive stars known. The strong stellar winds of these very luminous stars impact their evolution and the surrounding environment. We currently lack detailed knowledge of the wind structure that is needed to quantify this impact. Aims: To observationally constrain the stellar and wind properties of the massive stars in R136, in particular the parameters related to wind clumping. Methods: We simultaneously analyse optical and UV spectroscopy of 53 O-type and 3 WNh-stars using the FASTWIND model atmosphere code and a genetic algorithm. The models account for optically thick clumps and effects related to porosity and velocity-porosity, as well as a non-void interclump medium. Results: We obtain stellar parameters, surface abundances, mass-loss rates, terminal velocities and clumping characteristics and compare these to theoretical predictions and evolutionary models. The clumping properties include the density of the interclump medium and the velocity-porosity of the wind. For the first time, these characteristics are systematically measured for a wide range of effective temperatures and luminosities. Conclusions: We confirm a cluster age of 1.0-2.5 Myr and derive an initial stellar mass of $\geq 250 {\rm M}_\odot$ for the most massive star in our sample, R136a1. The winds of our sample stars are highly clumped, with an average clumping factor of $f_{\rm cl}=29\pm15$. We find tentative trends in the wind-structure parameters as a function of mass-loss rate, suggesting that the winds of stars with higher mass-loss rates are less clumped. We compare several theoretical predictions to the observed mass-loss rates and terminal velocities and find that none satisfactorily reproduces both quantities. The prescription of Krti膷ka & Kub谩t (2018) matches best the observed mass-loss rates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.11080v1-abstract-full').style.display = 'none'; document.getElementById('2202.11080v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in A&A; Appendix I will not be included in the published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 663, A36 (2022) </p> </li> </ol> <nav class="pagination is-small is-centered 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