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class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2502.02651">arXiv:2502.02651</a> <span> [<a href="https://arxiv.org/pdf/2502.02651">pdf</a>, <a href="https://arxiv.org/format/2502.02651">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> </div> </div> <p class="title is-5 mathjax"> Bar-spiral interaction produces radial migration and star formation bursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Marques%2C+L">L茅a Marques</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Wenger%2C+T+V">Trey V. Wenger</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">Marie Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">Georges Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Schultheis%2C+M">Mathias Schultheis</a>, <a href="/search/astro-ph?searchtype=author&query=Zucker%2C+D+B">Daniel B. Zucker</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="2502.02651v1-abstract-short" style="display: inline;"> Central bars and spirals are known to strongly impact the evolution of their host galaxies, both in terms of dynamics and star formation. Their typically different pattern speeds cause them to regularly overlap, which induces fluctuations in bar parameters. In this paper, we analyze both numerical simulations of disk galaxies and observational data to study the effect of bar-spiral physical overla… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.02651v1-abstract-full').style.display = 'inline'; document.getElementById('2502.02651v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.02651v1-abstract-full" style="display: none;"> Central bars and spirals are known to strongly impact the evolution of their host galaxies, both in terms of dynamics and star formation. Their typically different pattern speeds cause them to regularly overlap, which induces fluctuations in bar parameters. In this paper, we analyze both numerical simulations of disk galaxies and observational data to study the effect of bar-spiral physical overlap on stellar radial migration and star formation in the bar vicinity, as a function of time and galactic azimuth. We study three different numerical models, two of which are in a cosmological context, as well as APOGEE DR17 data and the WISE catalog of Galactic HII regions. We find that periodic boosts in stellar radial migration occur when the bar and spiral structure overlap. This mechanism causes net inward migration along the bar leading side, while stars along the bar trailling side and minor axis are shifted outward. The signature of bar-spiral induced migration is seen between the bar's inner Lindbald resonance and well outside its corotation, beyond which other drivers take over. We also find that, in agreement with simulations, APOGEE DR17 stars born at the bar vicinity (mostly metal-rich) can migrate out to the solar radius while remaining on cold orbits. For the Milky Way, 13% of stars in the solar vicinity were born inside the bar, compared to 5-20% in the simulations. Bar-spiral reconnections also result in periodic starbursts at the bar ends with an enhancement of up to a factor of 4, depending on the strength of the spiral structure. Similarly to the migration bursts, these do not always happen simultaneously at the two sides of the bar, hinting at the importance of odd spiral modes. Data from the WISE catalog suggest this phhenomenon is also relevant in our own Galaxy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.02651v1-abstract-full').style.display = 'none'; document.getElementById('2502.02651v1-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> 4 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </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+5 pages, 10+5 figures, submitted to A&A. Comments welcome!</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.18182">arXiv:2411.18182</a> <span> [<a href="https://arxiv.org/pdf/2411.18182">pdf</a>, <a href="https://arxiv.org/format/2411.18182">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> </div> </div> <p class="title is-5 mathjax"> Rediscovering the Milky Way with orbit superposition approach and APOGEE data III. Panoramic view of the bulge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Matteo%2C+P">Paola Di Matteo</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=van+de+Ven%2C+G">Glenn van de Ven</a>, <a href="/search/astro-ph?searchtype=author&query=Boin%2C+T">Tristan Boin</a>, <a href="/search/astro-ph?searchtype=author&query=Haywood%2C+M">Misha Haywood</a>, <a href="/search/astro-ph?searchtype=author&query=Kacharov%2C+N">Nikolay Kacharov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Krajnovic%2C+D">Davor Krajnovic</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">Marica Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">Roelof S. de Jong</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="2411.18182v1-abstract-short" style="display: inline;"> The innermost parts of the Milky Way (MW) are very difficult to observe due to the high extinction along the line of sight, especially close to the disc mid-plane. However, this region contains the most massive complex stellar component of the MW, the bulge, primarily composed of disc stars whose structure is (re-)shaped by the evolution of the bar. In this work, we extend the application of the o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.18182v1-abstract-full').style.display = 'inline'; document.getElementById('2411.18182v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.18182v1-abstract-full" style="display: none;"> The innermost parts of the Milky Way (MW) are very difficult to observe due to the high extinction along the line of sight, especially close to the disc mid-plane. However, this region contains the most massive complex stellar component of the MW, the bulge, primarily composed of disc stars whose structure is (re-)shaped by the evolution of the bar. In this work, we extend the application of the orbit superposition method to explore the present-day 3D structure, orbital composition, chemical abundance trends and kinematics of the MW bulge. Thanks to our approach, we are able to transfer astrometry from Gaia and stellar parameters from APOGEE DR 17 to map the inner MW without obscuration by the survey footprint and selection function. We demonstrate that the MW bulge is made of two main populations originating from a metal-poor, high-伪 thick disc and a metal-rich, low-伪 thin disc, with a mass ratio of 4:3, seen as two major components in the MDF. Finer MDF structures hint at multiple sub-populations associated with different orbital families of the bulge, which, however, have broad MDFs themselves. Decomposition using 2D GMMs in [Fe/H] -[Mg/Fe] identifies five components including a population with ex-situ origin. Two dominant ones correspond to the thin and thick discs and two in between trace the transition between them. We show that no universal metallicity gradient value can characterise the MW bulge. The radial gradients closely trace the X-shaped bulge density structure, while the vertical gradient variations follow the boxy component. While having, on average, subsolar metallicity, the MW bulge populations are more metal-rich compared to the surrounding disc, in agreement with extragalactic observations and state-of-the-art simulations reinforcing its secular origin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.18182v1-abstract-full').style.display = 'none'; document.getElementById('2411.18182v1-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 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">24 pages, 20 figures; 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/2411.16866">arXiv:2411.16866</a> <span> [<a href="https://arxiv.org/pdf/2411.16866">pdf</a>, <a href="https://arxiv.org/format/2411.16866">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> </div> </div> <p class="title is-5 mathjax"> Rediscovering the Milky Way with orbit superposition approach and APOGEE data II. Chrono-chemo-kinematics of the disc </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Haywood%2C+M">Misha Haywood</a>, <a href="/search/astro-ph?searchtype=author&query=van+de+Ven%2C+G">Glenn van de Ven</a>, <a href="/search/astro-ph?searchtype=author&query=Krajnovic%2C+D">Davor Krajnovic</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Matteo%2C+P">Paola Di Matteo</a>, <a href="/search/astro-ph?searchtype=author&query=Kacharov%2C+N">Nikolay Kacharov</a>, <a href="/search/astro-ph?searchtype=author&query=Marques%2C+L">L茅a Marques</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">Marica Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">Roelof S. de Jong</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="2411.16866v1-abstract-short" style="display: inline;"> The stellar disc is the dominant luminous component of the Milky Way (MW). Although our understanding of its structure is rapidly expanding due to advances in large-scale stellar surveys, our picture of the MW disc remains substantially obscured by selection functions and incomplete spatial coverage of observational data. In this work, we present the comprehensive chrono-chemo-kinematic structure… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.16866v1-abstract-full').style.display = 'inline'; document.getElementById('2411.16866v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.16866v1-abstract-full" style="display: none;"> The stellar disc is the dominant luminous component of the Milky Way (MW). Although our understanding of its structure is rapidly expanding due to advances in large-scale stellar surveys, our picture of the MW disc remains substantially obscured by selection functions and incomplete spatial coverage of observational data. In this work, we present the comprehensive chrono-chemo-kinematic structure of the MW disc, recovered using a novel orbit superposition approach combined with data from APOGEE DR 17. We detect periodic azimuthal metallicity variations within 6-8 kpc with an amplitude of 0.05-0.1 dex peaking along the bar major axis. The radial metallicity profile of the MW also varies with azimuth, displaying a pattern typical among other disc galaxies: a decline outside the solar radius and an almost flat profile in the inner region, attributed to the presence of old, metal-poor high-伪 populations, which comprise about 40% of the total stellar mass. The geometrically defined thick disc and the high-伪 populations have comparable masses, with differences in their stellar population content, which we quantify using the reconstructed 3D MW structure. The well-known [伪/Fe]-bimodality in the MW disc, once weighted by stellar mass, is less pronounced at a given metallicity for the whole galaxy but distinctly visible in a narrow range of galactic radii (5-9 kpc), explaining its relative lack of prominence in external galaxies and galaxy formation simulations. Analysing a more evident double age-abundance sequence, we construct a scenario for the MW disc formation, advocating for an inner/outer disc dichotomy genetically linked to the MW's evolutionary stages. In this picture, the extended solar vicinity is a transition zone that shares chemical properties of both the inner (old age-metallicity sequence) and outer discs (young age-metallicity sequence). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.16866v1-abstract-full').style.display = 'none'; document.getElementById('2411.16866v1-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 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">36 pages, 34 figures; 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/2411.15062">arXiv:2411.15062</a> <span> [<a href="https://arxiv.org/pdf/2411.15062">pdf</a>, <a href="https://arxiv.org/format/2411.15062">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> </div> </div> <p class="title is-5 mathjax"> Rediscovering the Milky Way with orbit superposition approach and APOGEE data I. Method validation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=van+de+Ven%2C+G">Glenn van de Ven</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Krajnovic%2C+D">Davor Krajnovic</a>, <a href="/search/astro-ph?searchtype=author&query=Haywood%2C+M">Misha Haywood</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Matteo%2C+P">Paola Di Matteo</a>, <a href="/search/astro-ph?searchtype=author&query=Kacharov%2C+N">Nikolay Kacharov</a>, <a href="/search/astro-ph?searchtype=author&query=Marques%2C+L">L茅a Marques</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">Marica Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">Roelof S. de Jong</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="2411.15062v1-abstract-short" style="display: inline;"> We introduce a novel orbit superposition method designed to reconstruct the stellar density structure, kinematics, and chemical abundance distribution of the entire Milky Way by leveraging 6D phase-space information from its resolved stellar populations, limited by the spatial coverage of APOGEE DR17. </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.15062v1-abstract-full" style="display: none;"> We introduce a novel orbit superposition method designed to reconstruct the stellar density structure, kinematics, and chemical abundance distribution of the entire Milky Way by leveraging 6D phase-space information from its resolved stellar populations, limited by the spatial coverage of APOGEE DR17. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.15062v1-abstract-full').style.display = 'none'; document.getElementById('2411.15062v1-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 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">17 pages, 13 figures, 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/2410.17326">arXiv:2410.17326</a> <span> [<a href="https://arxiv.org/pdf/2410.17326">pdf</a>, <a href="https://arxiv.org/format/2410.17326">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> </div> </div> <p class="title is-5 mathjax"> Evolution of the radial ISM metallicity gradient in the Milky Way disk since redshift $\approx 3$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+N+D">Nathan D. Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Marques%2C+L">L茅a Marques</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+L">Lucy Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</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="2410.17326v1-abstract-short" style="display: inline;"> Recent works identified a way to recover the time evolution of a galaxy's disk metallicity gradient from the shape of its age--metallicity relation. However, the success of the method is dependent on how the width of the star-forming region evolves over time, which in turn is dependent on a galaxy's present-day bar strength. In this paper, we account for the time variation in the width of the star… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17326v1-abstract-full').style.display = 'inline'; document.getElementById('2410.17326v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.17326v1-abstract-full" style="display: none;"> Recent works identified a way to recover the time evolution of a galaxy's disk metallicity gradient from the shape of its age--metallicity relation. However, the success of the method is dependent on how the width of the star-forming region evolves over time, which in turn is dependent on a galaxy's present-day bar strength. In this paper, we account for the time variation in the width of the star-forming region when deriving the interstellar medium (ISM) metallicity gradient evolution over time ($\rm \nabla [Fe/H](蟿)$), which provides more realistic birth radii estimates of Milky Way (MW) disk stars. Using MW/Andromeda analogues from the TNG50 simulation, we quantified the disk growth of newly born stars as a function of present-day bar strength to provide a correction that improves recovery of $\rm \nabla [Fe/H](蟿)$. In TNG50, we find that our correction reduces the median absolute error in recovering $\rm \nabla [Fe/H] (蟿)$ by over 30%. To confirm its universality, we test our correction on two galaxies from NIHAO-UHD and find the median absolute error is over 3 times smaller even in the presence of observational uncertainties for the barred, MW-like galaxy. Applying our correction to APOGEE DR17 red giant MW disk stars suggests the effects of merger events on $\rm \nabla [Fe/H](蟿)$ are less significant than originally found, and the corresponding estimated birth radii expose epochs when different migration mechanisms dominated. Our correction to account for the growth of the star-forming region in the disk allows for better recovery of the evolution of the MW disk's ISM metallicity gradient and, thus, more meaningful stellar birth radii estimates. With our results, we are able to suggest the evolution of not only the ISM gradient, but also the total stellar disk radial metallicity gradient, providing key constraints to select MW analogues across redshift. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17326v1-abstract-full').style.display = 'none'; document.getElementById('2410.17326v1-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 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">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/2409.10598">arXiv:2409.10598</a> <span> [<a href="https://arxiv.org/pdf/2409.10598">pdf</a>, <a href="https://arxiv.org/format/2409.10598">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> </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/10.1051/0004-6361/202452219">10.1051/0004-6361/202452219 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Effects of secular growth and mergers on the evolution of metallicity gradients and azimuthal variations in a Milky Way-like galaxy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Renaud%2C+F">Florent Renaud</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Haywood%2C+M">Misha Haywood</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Matteo%2C+P">Paola Di Matteo</a>, <a href="/search/astro-ph?searchtype=author&query=Agertz%2C+O">Oscar Agertz</a>, <a href="/search/astro-ph?searchtype=author&query=Romeo%2C+A+B">Alessandro B. Romeo</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="2409.10598v2-abstract-short" style="display: inline;"> We analyze the evolution of the radial profiles and the azimuthal variations of the stellar metallicities from the Vintergatan simulation of a Milky Way-like galaxy. We find that negative gradients exist as soon as the disk settles at high redshift, and are maintained throughout the long term evolution of the galaxy, including during major merger events. The inside-out growth of the disk and an ov… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.10598v2-abstract-full').style.display = 'inline'; document.getElementById('2409.10598v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.10598v2-abstract-full" style="display: none;"> We analyze the evolution of the radial profiles and the azimuthal variations of the stellar metallicities from the Vintergatan simulation of a Milky Way-like galaxy. We find that negative gradients exist as soon as the disk settles at high redshift, and are maintained throughout the long term evolution of the galaxy, including during major merger events. The inside-out growth of the disk and an overall outward radial migration tend to flatten these gradients in time. Major merger events only have a moderate and short-lived imprint on the [Fe/H] distributions with almost no radial dependence. The reason lies in the timescale for enrichment in Fe being significantly longer than the duration of the starbursts episodes, themselves slower than dynamical mixing during typical interactions. It results that signatures of major mergers become undetectable in [Fe/H] only a few Myr after pericenter passages. We note that considering other tracers like the warm interstellar medium, or monitoring the evolution of the metallicity gradient as a single value instead of a radial full profile could lead to different interpretations, and warn against an oversimplification of this complex problem. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.10598v2-abstract-full').style.display = 'none'; document.getElementById('2409.10598v2-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> 29 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 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">A&A accepted</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 694, A56 (2025) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.11025">arXiv:2405.11025</a> <span> [<a href="https://arxiv.org/pdf/2405.11025">pdf</a>, <a href="https://arxiv.org/format/2405.11025">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> </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/10.1051/0004-6361/202450754">10.1051/0004-6361/202450754 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> (Re)mind the gap: a hiatus in star formation history unveiled by APOGEE DR17 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Spitoni%2C+E">E. Spitoni</a>, <a href="/search/astro-ph?searchtype=author&query=Matteucci%2C+F">F. Matteucci</a>, <a href="/search/astro-ph?searchtype=author&query=Gratton%2C+R">R. Gratton</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">B. Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Cescutti%2C+G">G. Cescutti</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="2405.11025v2-abstract-short" style="display: inline;"> The analysis of several spectroscopic surveys indicates the presence of a bimodality between the disc stars in the abundance ratio space of [$伪$/Fe] versus [Fe/H]. The two stellar groups are commonly referred to as the high-$伪$ and low-$伪$ sequences. Some models capable of reproducing such a bimodality, invoke the presence of a hiatus in the star formation history in our Galaxy, whereas other mode… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.11025v2-abstract-full').style.display = 'inline'; document.getElementById('2405.11025v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.11025v2-abstract-full" style="display: none;"> The analysis of several spectroscopic surveys indicates the presence of a bimodality between the disc stars in the abundance ratio space of [$伪$/Fe] versus [Fe/H]. The two stellar groups are commonly referred to as the high-$伪$ and low-$伪$ sequences. Some models capable of reproducing such a bimodality, invoke the presence of a hiatus in the star formation history in our Galaxy, whereas other models explain the two sequences by means of stellar migration. Our aim is to show that the existence of the gap in the star formation rate between high-$伪$ and low-$伪$ is evident in the stars of APOGEE DR17, if one plots [Fe/$伪$] versus [$伪$/H], thus confirming previous suggestions by Gratton et al. (1996) and Fuhrmann (1998). Then we try to interpret the data by means of detailed chemical models. We compare the APOGEE DR17 red giant stars with the predictions of a detailed chemical evolution model based on the two-infall paradigm, taking also into account possible accretion of dwarf satellites. The APOGEE DR17 abundance ratios [Fe/$伪$] versus [$伪$/H] exhibit a sharp increase of [Fe/$伪$] at a nearly constant [$伪$/H] (where $伪$ elements considered are Mg, Si, O) during the transition between the two disc phases. This observation strongly supports the hypothesis that a hiatus in star formation occurred during this evolutionary phase. Notably, the most pronounced growth in the [Fe/$伪$] versus [$伪$/H] relation is observed for oxygen, as this element is exclusively synthesised in core-collapse supernovae. A chemical model predicting a stop in the star formation of a duration of roughly 3.5 Gyr, and where the high-$伪$ disc starts forming from pre-enriched gas by a previous encounter with a dwarf galaxy can well explain the observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.11025v2-abstract-full').style.display = 'none'; document.getElementById('2405.11025v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 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">Accepted for publication in Astronomy and Astrophysics (A&A), 16 pages, 13 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 690, A208 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.05398">arXiv:2403.05398</a> <span> [<a href="https://arxiv.org/pdf/2403.05398">pdf</a>, <a href="https://arxiv.org/format/2403.05398">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</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="Earth and Planetary Astrophysics">astro-ph.EP</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> <p class="title is-5 mathjax"> The Wide-field Spectroscopic Telescope (WST) Science White Paper </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Mainieri%2C+V">Vincenzo Mainieri</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+R+I">Richard I. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Brinchmann%2C+J">Jarle Brinchmann</a>, <a href="/search/astro-ph?searchtype=author&query=Cimatti%2C+A">Andrea Cimatti</a>, <a href="/search/astro-ph?searchtype=author&query=Ellis%2C+R+S">Richard S. Ellis</a>, <a href="/search/astro-ph?searchtype=author&query=Hill%2C+V">Vanessa Hill</a>, <a href="/search/astro-ph?searchtype=author&query=Kneib%2C+J">Jean-Paul Kneib</a>, <a href="/search/astro-ph?searchtype=author&query=McLeod%2C+A+F">Anna F. McLeod</a>, <a href="/search/astro-ph?searchtype=author&query=Opitom%2C+C">Cyrielle Opitom</a>, <a href="/search/astro-ph?searchtype=author&query=Roth%2C+M+M">Martin M. Roth</a>, <a href="/search/astro-ph?searchtype=author&query=Sanchez-Saez%2C+P">Paula Sanchez-Saez</a>, <a href="/search/astro-ph?searchtype=author&query=Smiljanic%2C+R">Rodolfo Smiljanic</a>, <a href="/search/astro-ph?searchtype=author&query=Tolstoy%2C+E">Eline Tolstoy</a>, <a href="/search/astro-ph?searchtype=author&query=Bacon%2C+R">Roland Bacon</a>, <a href="/search/astro-ph?searchtype=author&query=Randich%2C+S">Sofia Randich</a>, <a href="/search/astro-ph?searchtype=author&query=Adamo%2C+A">Angela Adamo</a>, <a href="/search/astro-ph?searchtype=author&query=Annibali%2C+F">Francesca Annibali</a>, <a href="/search/astro-ph?searchtype=author&query=Arevalo%2C+P">Patricia Arevalo</a>, <a href="/search/astro-ph?searchtype=author&query=Audard%2C+M">Marc Audard</a>, <a href="/search/astro-ph?searchtype=author&query=Barsanti%2C+S">Stefania Barsanti</a>, <a href="/search/astro-ph?searchtype=author&query=Battaglia%2C+G">Giuseppina Battaglia</a>, <a href="/search/astro-ph?searchtype=author&query=Aran%2C+A+M+B">Amelia M. Bayo Aran</a>, <a href="/search/astro-ph?searchtype=author&query=Belfiore%2C+F">Francesco Belfiore</a>, <a href="/search/astro-ph?searchtype=author&query=Bellazzini%2C+M">Michele Bellazzini</a>, <a href="/search/astro-ph?searchtype=author&query=Bellini%2C+E">Emilio Bellini</a> , et al. (192 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="2403.05398v2-abstract-short" style="display: inline;"> The Wide-field Spectroscopic Telescope (WST) is proposed as a new facility dedicated to the efficient delivery of spectroscopic surveys. This white paper summarises the initial concept as well as the corresponding science cases. WST will feature simultaneous operation of a large field-of-view (3 sq. degree), a high multiplex (20,000) multi-object spectrograph (MOS) and a giant 3x3 sq. arcmin integ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.05398v2-abstract-full').style.display = 'inline'; document.getElementById('2403.05398v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.05398v2-abstract-full" style="display: none;"> The Wide-field Spectroscopic Telescope (WST) is proposed as a new facility dedicated to the efficient delivery of spectroscopic surveys. This white paper summarises the initial concept as well as the corresponding science cases. WST will feature simultaneous operation of a large field-of-view (3 sq. degree), a high multiplex (20,000) multi-object spectrograph (MOS) and a giant 3x3 sq. arcmin integral field spectrograph (IFS). In scientific capability these requirements place WST far ahead of existing and planned facilities. Given the current investment in deep imaging surveys and noting the diagnostic power of spectroscopy, WST will fill a crucial gap in astronomical capability and work synergistically with future ground and space-based facilities. This white paper shows that WST can address outstanding scientific questions in the areas of cosmology; galaxy assembly, evolution, and enrichment, including our own Milky Way; origin of stars and planets; time domain and multi-messenger astrophysics. WST's uniquely rich dataset will deliver unforeseen discoveries in many of these areas. The WST Science Team (already including more than 500 scientists worldwide) is open to the all astronomical community. To register in the WST Science Team please visit https://www.wstelescope.com/for-scientists/participate <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.05398v2-abstract-full').style.display = 'none'; document.getElementById('2403.05398v2-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">194 pages, 66 figures. Comments are welcome (wstelescope@gmail.com)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.09260">arXiv:2401.09260</a> <span> [<a href="https://arxiv.org/pdf/2401.09260">pdf</a>, <a href="https://arxiv.org/format/2401.09260">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> </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/10.1051/0004-6361/202449268">10.1051/0004-6361/202449268 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Empirical derivation of the metallicity evolution with time and radius using TNG50 Milky Way/Andromeda analogues </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">B. Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">S. Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+L">L. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">R. S. de Jong</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</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="2401.09260v2-abstract-short" style="display: inline;"> Recent works have used a linear birth metallicity gradient to estimate the evolution of the [Fe/H] profile in the Galactic disk over time, and infer stellar birth radii (R$_\text{birth}$) from [Fe/H] and age measurements. These estimates rely on the evolution of [Fe/H] at the Galactic center ([Fe/H](0, $蟿$)) and the birth metallicity gradient ($\nabla$[Fe/H]($蟿)$) over time -- quantities that are… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.09260v2-abstract-full').style.display = 'inline'; document.getElementById('2401.09260v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.09260v2-abstract-full" style="display: none;"> Recent works have used a linear birth metallicity gradient to estimate the evolution of the [Fe/H] profile in the Galactic disk over time, and infer stellar birth radii (R$_\text{birth}$) from [Fe/H] and age measurements. These estimates rely on the evolution of [Fe/H] at the Galactic center ([Fe/H](0, $蟿$)) and the birth metallicity gradient ($\nabla$[Fe/H]($蟿)$) over time -- quantities that are unknown and inferred under key assumptions. In this work, we use the sample of Milky Way/Andromeda analogues from the TNG50 simulation to investigate the ability to recover [Fe/H](R, $蟿$) and R$_\text{birth}$ in a variety of galaxies. Using stellar disk particles, we test the assumptions required in estimating R$_\text{birth}$, [Fe/H](0, $蟿$), and $\nabla$[Fe/H]($蟿)$ using recently proposed methods to understand when they are valid. We show that $\nabla$[Fe/H]($蟿)$ can be recovered in most galaxies to within 26% from the range in [Fe/H] across age, with better accuracy for more massive and stronger barred galaxies. We also find that the true central metallicity is unrepresentative of the genuine disk [Fe/H] profile; thus we propose to use a projected central metallicity instead. About half of the galaxies in our sample do not have a continuously enriching projected central metallicity, with a dilution in [Fe/H] correlating with mergers. Most importantly, galaxy-specific [Fe/H](R, $蟿$) can be constrained and confirmed by requiring the R$_\text{birth}$ distributions of mono-age, solar neighborhood populations to follow inside-out formation. We conclude that examining trends with R$_\text{birth}$ is valid for the Milky Way disk and similarly structured galaxies, where we expect R$_\text{birth}$ can be recovered to within 20% assuming today's measurement uncertainties in TNG50. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.09260v2-abstract-full').style.display = 'none'; document.getElementById('2401.09260v2-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> 14 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">Version accepted at 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, A352 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.07219">arXiv:2312.07219</a> <span> [<a href="https://arxiv.org/pdf/2312.07219">pdf</a>, <a href="https://arxiv.org/format/2312.07219">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> </div> </div> <p class="title is-5 mathjax"> LMC Stars and Where to Find Them: Inferring Birth Radii for External Galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yuxi"> Yuxi</a>, <a href="/search/astro-ph?searchtype=author&query=Lu"> Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Nidever%2C+D">David Nidever</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Macci%C3%B2%2C+A+V">Andrea V. Macci貌</a>, <a href="/search/astro-ph?searchtype=author&query=Obreja%2C+A">Aura Obreja</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="2312.07219v1-abstract-short" style="display: inline;"> It is well known that stars move away from their birth location over time via radial migration. This dynamical process makes computing the correct chemical evolution, e.g., metallicity gradients, of galaxies very difficult. This dynamical process makes inferring the chemical evolution of observed galaxies from their measured abundance gradients very difficult. One way to account for radial migrati… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.07219v1-abstract-full').style.display = 'inline'; document.getElementById('2312.07219v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.07219v1-abstract-full" style="display: none;"> It is well known that stars move away from their birth location over time via radial migration. This dynamical process makes computing the correct chemical evolution, e.g., metallicity gradients, of galaxies very difficult. This dynamical process makes inferring the chemical evolution of observed galaxies from their measured abundance gradients very difficult. One way to account for radial migration is to infer stellar birth radii for individual stars. Many attempts to do so have been performed over the last years, but are limited to the Milky Way as computing the birth position of stars requires precise measurements of stellar metallicity and age for individual stars that cover large Galactic radii. Fortunately, recent and future surveys will provide numerous opportunities for inferring birth radii for external galaxies such as the Large Magellanic Cloud (LMC). In this paper, we investigate the possibility of doing so using the NIHAO cosmological zoom-in simulations. We find that it is theoretically possible to infer birth radii with a ~ 25% median uncertainty for individual stars in galaxies with i) orderliness of the orbits, $\langle v_蠁\rangle/蟽_{v} >$ 2, ii) a dark matter halo mass greater or equal to approximately the LMC mass (~ 2 x 10$^{11} M_\odot$), and iii) after the average azimuthal velocity of the stellar disk reaches ~70% of its maximum. From our analysis, we conclude that it is possible and useful to infer birth radii for the LMC and other external galaxies that satisfy the above criteria. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.07219v1-abstract-full').style.display = 'none'; document.getElementById('2312.07219v1-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 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">8 pages, 8 figures. Missing citations welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.03854">arXiv:2312.03854</a> <span> [<a href="https://arxiv.org/pdf/2312.03854">pdf</a>, <a href="https://arxiv.org/format/2312.03854">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> </div> </div> <p class="title is-5 mathjax"> Gaia DR3 data consistent with a short bar connected to a spiral arm </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Vislosky%2C+E">E. Vislosky</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">S. Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">M. Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">T. Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Hilmi%2C+T">T. Hilmi</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">B. Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Bland-Hawthorn%2C+J">J. Bland-Hawthorn</a>, <a href="/search/astro-ph?searchtype=author&query=Quillen%2C+A+C">A. C. Quillen</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R">R. de Jong</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="2312.03854v2-abstract-short" style="display: inline;"> We use numerical simulations to model Gaia DR3 data with the aim of constraining the Milky Way bar and spiral structure parameters. We show that both the morphology and the velocity field in Milky Way-like galactic disc models are strong functions of time, changing dramatically over a few tens of Myr. This suggests that by finding a good match to the observed radial velocity field, v_R(x,y), we ca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.03854v2-abstract-full').style.display = 'inline'; document.getElementById('2312.03854v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.03854v2-abstract-full" style="display: none;"> We use numerical simulations to model Gaia DR3 data with the aim of constraining the Milky Way bar and spiral structure parameters. We show that both the morphology and the velocity field in Milky Way-like galactic disc models are strong functions of time, changing dramatically over a few tens of Myr. This suggests that by finding a good match to the observed radial velocity field, v_R(x,y), we can constrain the bar-spiral orientation. Incorporating uncertainties into our models is necessary to match the data; most importantly, a heliocentric distance uncertainty above 10-15% distorts the bar's shape and v_R quadrupole pattern morphology, and decreases its apparent angle with respect to the Sun-Galactocentric line. An excellent match to the Gaia DR3 v_R(x,y) field is found for a simulation with a bar length R_b\approx3.6 kpc. We argue that the data are consistent with a MW bar as short as ~3 kpc, for moderate strength inner disc spiral structure (A_2/A_0\approx0.25) or, alternatively, with a bar length up to ~5.2 kpc, provided that spiral arms are quite weak (A_2/A_0\approx0.1), and is most likely in the process of disconnecting from a spiral arm. We demonstrate that the bar angle and distance uncertainty can similarly affect the match between our models and the data - a smaller bar angle (20 deg instead of 30 deg) requires smaller distance uncertainty (20% instead of 30%) to explain the observations. Fourier components of the face-on density distribution of our models suggest that the MW does not have strong m=1 and/or m=3 spirals near the solar radius. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.03854v2-abstract-full').style.display = 'none'; document.getElementById('2312.03854v2-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> 4 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">17p, 12 figs. Accepted to MNRAS on Dec 22, 2023</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.11504">arXiv:2310.11504</a> <span> [<a href="https://arxiv.org/pdf/2310.11504">pdf</a>, <a href="https://arxiv.org/format/2310.11504">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> </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/10.1051/0004-6361/202347325">10.1051/0004-6361/202347325 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> 2D chemical evolution models II. Effects of multiple spiral arm patterns on O, Eu, Fe and Ba abundance gradients </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Spitoni%2C+E">E. Spitoni</a>, <a href="/search/astro-ph?searchtype=author&query=Cescutti%2C+G">G. Cescutti</a>, <a href="/search/astro-ph?searchtype=author&query=Recio-Blanco%2C+A">A. Recio-Blanco</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Poggio%2C+E">E. Poggio</a>, <a href="/search/astro-ph?searchtype=author&query=Palicio%2C+P+A">P. A. Palicio</a>, <a href="/search/astro-ph?searchtype=author&query=Matteucci%2C+F">F. Matteucci</a>, <a href="/search/astro-ph?searchtype=author&query=Peirani%2C+S">S. Peirani</a>, <a href="/search/astro-ph?searchtype=author&query=Barbillon%2C+M">M. Barbillon</a>, <a href="/search/astro-ph?searchtype=author&query=Vasini%2C+A">A. Vasini</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="2310.11504v1-abstract-short" style="display: inline;"> According to observations and numerical simulations, the Milky Way could exhibit several spiral arm modes with multiple pattern speeds, wherein the slower patterns are located at larger Galactocentric distances. Our aim is to quantify the effects of the spiral arms on the azimuthal variations of the chemical abundances for oxygen, iron and for the first time for neutron-capture elements (europium… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.11504v1-abstract-full').style.display = 'inline'; document.getElementById('2310.11504v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.11504v1-abstract-full" style="display: none;"> According to observations and numerical simulations, the Milky Way could exhibit several spiral arm modes with multiple pattern speeds, wherein the slower patterns are located at larger Galactocentric distances. Our aim is to quantify the effects of the spiral arms on the azimuthal variations of the chemical abundances for oxygen, iron and for the first time for neutron-capture elements (europium and barium) in the Galactic disc. We assume a model based on multiple spiral arm modes with different pattern speeds. The resulting model represents an updated version of previous 2D chemical evolution models. We apply new analytical prescriptions for the spiral arms in a 2D Galactic disc chemical evolution model, exploring the possibility that the spiral structure is formed by the overlap of chunks with different pattern speeds and spatial extent. The predicted azimuthal variations in abundance gradients are dependent on the considered chemical element. Elements synthesised on short time scales (i.e., oxygen and europium in this study) exhibit larger abundance fluctuations. In fact, for progenitors with short lifetimes, the chemical elements restored into the ISM perfectly trace the star formation perturbed by the passage of the spiral arms. The map of the star formation rate predicted by our chemical evolution model with multiple patterns of spiral arms presents arcs and arms compatible with those revealed by multiple tracers (young upper main sequence stars, Cepheids, and distribution of stars with low radial actions). Finally, our model predictions are in good agreement with the azimuthal variations that emerged from the analysis of Gaia DR3 GSP-Spec [M/H] abundance ratios, if at most recent times the pattern speeds match the Galactic rotational curve at all radii. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.11504v1-abstract-full').style.display = 'none'; document.getElementById('2310.11504v1-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> 17 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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 and Astrophysics (A&A), 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 680, 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/2310.05287">arXiv:2310.05287</a> <span> [<a href="https://arxiv.org/pdf/2310.05287">pdf</a>, <a href="https://arxiv.org/format/2310.05287">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> </div> </div> <p class="title is-5 mathjax"> Dead man tells tales: metallicity distribution of the Milky Way stellar halo reveals the past of the GSE progenitor galaxy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Marabotto%2C+J">Julien Marabotto</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">Georges Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+J+D">Jeicot Delgado Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N">Noam Libeskind</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="2310.05287v1-abstract-short" style="display: inline;"> The Gaia-Sausage-Enceladus~(GSE) stands out as the largest known ancient accretion event in the Milky Way~(MW) history. Despite this significance, the parameters of its progenitor galaxy are still poorly constrained. We identify GSE stars from the APOGEE DR17 using Gaussian mixture models and recover a negative radial metallicity gradient for the GSE debris within the MW stellar halo, with a magni… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.05287v1-abstract-full').style.display = 'inline'; document.getElementById('2310.05287v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.05287v1-abstract-full" style="display: none;"> The Gaia-Sausage-Enceladus~(GSE) stands out as the largest known ancient accretion event in the Milky Way~(MW) history. Despite this significance, the parameters of its progenitor galaxy are still poorly constrained. We identify GSE stars from the APOGEE DR17 using Gaussian mixture models and recover a negative radial metallicity gradient for the GSE debris within the MW stellar halo, with a magnitude of $\approx -0.014^{-0.002}_{-0.022}$ dex/kpc. We argue that this gradient reflects the radial metallicity gradient of the GSE galaxy progenitor before it was disrupted by the MW. By investigating the cosmological HESTIA simulations and $N$-body models of galaxy mergers, we constrain the radial metallicity gradient of the GSE-progenitor to be $\approx -0.1^{-0.06}_{-0.15}$ dex/kpc. We, therefore, propose that a chemical tagging of accreted stars using their integrals of motion, although they are not conserved during mergers, provide essential information about the structure and the past of systems accreted onto the MW. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.05287v1-abstract-full').style.display = 'none'; document.getElementById('2310.05287v1-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">12 pages, 6 figures; 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/2309.07321">arXiv:2309.07321</a> <span> [<a href="https://arxiv.org/pdf/2309.07321">pdf</a>, <a href="https://arxiv.org/format/2309.07321">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> </div> </div> <p class="title is-5 mathjax"> Why does the Milky Way have a bar? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Walcher%2C+J+C">Jakob C. Walcher</a>, <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N">Noam Libeskind</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="2309.07321v2-abstract-short" style="display: inline;"> There is no doubt that the Milky Way is a barred galaxy; however, factors that establish its prominent morphology remain largely elusive and poorly comprehended. In this work, we attempt to constrain the history of the MW by tracing the present-day parameters and evolution of a set of MW and M31 analogues from the TNG50 cosmological simulations. We find that the strength of bars at $z=0$ correlate… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.07321v2-abstract-full').style.display = 'inline'; document.getElementById('2309.07321v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.07321v2-abstract-full" style="display: none;"> There is no doubt that the Milky Way is a barred galaxy; however, factors that establish its prominent morphology remain largely elusive and poorly comprehended. In this work, we attempt to constrain the history of the MW by tracing the present-day parameters and evolution of a set of MW and M31 analogues from the TNG50 cosmological simulations. We find that the strength of bars at $z=0$ correlates well not only with the total mass build-up of galaxies but, more crucially, with the time of rapid onset of stellar discs. Discs of strongly barred galaxies form early ($ z \gtrsim 2-3$), compared to weakly barred and non-barred galaxies ($z \approx 1-1.5$). Although we are cautious to draw ultimate conclusions about the governing factor of discs formation due to the complexity and correlations between different physical phenomena~(dark matter mass growth, gas accretion rate, mergers and others) affecting galaxy growth, the observed morphological diversity of galaxies can be tentatively explained by a substantial variation in the gas angular momentum around proto-galaxies already at $z\approx 3-5$; in such a way, early discs with the strongest bars at $z=0$ formed from gas with the largest angular momentum. By comparing the formation time scales of discs of barred galaxies in the TNG50 sample, we suggest that the MW has a strong bar ($0.35<A_2<0.6$) and that its stellar disc started to dominate over the spheroidal component already at $z \approx 2$, with a mass of $\approx 1 \pm 0.5 \times 10^{10} M_\odot$. We, therefore, conclude that the presence of a strong bar in the MW is a natural manifestation of the early formation of the stellar disc, which made possible bursty but highly efficient star formation at high redshift. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.07321v2-abstract-full').style.display = 'none'; document.getElementById('2309.07321v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 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">12 pages, 10 figures, MNRAS in press</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.11159">arXiv:2307.11159</a> <span> [<a href="https://arxiv.org/pdf/2307.11159">pdf</a>, <a href="https://arxiv.org/format/2307.11159">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> </div> </div> <p class="title is-5 mathjax"> Chemical clocks and their time zones: understanding the [s/Mg]--age relation with birth radii </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Cescutti%2C+G">Gabriele Cescutti</a>, <a href="/search/astro-ph?searchtype=author&query=Spitoni%2C+E">Emanuele Spitoni</a>, <a href="/search/astro-ph?searchtype=author&query=J%C3%B6nsson%2C+H">Henrik J枚nsson</a>, <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">Friedrich Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A">Anna Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</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="2307.11159v1-abstract-short" style="display: inline;"> The relative enrichment of s-process to $伪$-elements ([s/$伪$]) has been linked with age, providing a potentially useful avenue in exploring the Milky Way's chemical evolution. However, the age--[s/$伪$] relationship is non-universal, with dependencies on metallicity and current location in the Galaxy. In this work, we examine these chemical clock tracers across birth radii (… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.11159v1-abstract-full').style.display = 'inline'; document.getElementById('2307.11159v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.11159v1-abstract-full" style="display: none;"> The relative enrichment of s-process to $伪$-elements ([s/$伪$]) has been linked with age, providing a potentially useful avenue in exploring the Milky Way's chemical evolution. However, the age--[s/$伪$] relationship is non-universal, with dependencies on metallicity and current location in the Galaxy. In this work, we examine these chemical clock tracers across birth radii ($\rm \text{R}_\text{birth}$), recovering the inherent trends between the variables. We derive $\rm \text{R}_\text{birth}$ and explore the [s/$伪$]--age--$\rm \text{R}_\text{birth}$ relationship for 36,652 APOGEE DR17 red giant and 24,467 GALAH DR3 main sequence turnoff and subgiant branch disk stars using [Ce/Mg], [Ba/Mg], and [Y/Mg]. We discover that the age--[s/Mg] relation is strongly dependent on birth location in the Milky Way, with stars born in the inner disk having the weakest correlation. This is congruent with the Galaxy's initially weak, negative [s/Mg] radial gradient, which becomes positive and steep with time. We show that the non-universal relations of chemical clocks is caused by their fundamental trends with $\rm \text{R}_\text{birth}$ over time, and suggest that the tight age--[s/Mg] relation obtained with solar-like stars is due to similar $\rm \text{R}_\text{birth}$ for a given age. Our results are put into context with a Galactic chemical evolution model, where we demonstrate the need for data-driven nucleosynthetic yields. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.11159v1-abstract-full').style.display = 'none'; document.getElementById('2307.11159v1-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> 20 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">submitted to 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/2306.11784">arXiv:2306.11784</a> <span> [<a href="https://arxiv.org/pdf/2306.11784">pdf</a>, <a href="https://arxiv.org/format/2306.11784">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> NANCY: Next-generation All-sky Near-infrared Community surveY </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Han%2C+J+J">Jiwon Jesse Han</a>, <a href="/search/astro-ph?searchtype=author&query=Dey%2C+A">Arjun Dey</a>, <a href="/search/astro-ph?searchtype=author&query=Price-Whelan%2C+A+M">Adrian M. Price-Whelan</a>, <a href="/search/astro-ph?searchtype=author&query=Najita%2C+J">Joan Najita</a>, <a href="/search/astro-ph?searchtype=author&query=Schlafly%2C+E+F">Edward F. Schlafly</a>, <a href="/search/astro-ph?searchtype=author&query=Saydjari%2C+A">Andrew Saydjari</a>, <a href="/search/astro-ph?searchtype=author&query=Wechsler%2C+R+H">Risa H. Wechsler</a>, <a href="/search/astro-ph?searchtype=author&query=Bonaca%2C+A">Ana Bonaca</a>, <a href="/search/astro-ph?searchtype=author&query=Schlegel%2C+D+J">David J Schlegel</a>, <a href="/search/astro-ph?searchtype=author&query=Conroy%2C+C">Charlie Conroy</a>, <a href="/search/astro-ph?searchtype=author&query=Raichoor%2C+A">Anand Raichoor</a>, <a href="/search/astro-ph?searchtype=author&query=Drlica-Wagner%2C+A">Alex Drlica-Wagner</a>, <a href="/search/astro-ph?searchtype=author&query=Kollmeier%2C+J+A">Juna A. Kollmeier</a>, <a href="/search/astro-ph?searchtype=author&query=Koposov%2C+S+E">Sergey E. Koposov</a>, <a href="/search/astro-ph?searchtype=author&query=Besla%2C+G">Gurtina Besla</a>, <a href="/search/astro-ph?searchtype=author&query=Rix%2C+H">Hans-Walter Rix</a>, <a href="/search/astro-ph?searchtype=author&query=Goodman%2C+A">Alyssa Goodman</a>, <a href="/search/astro-ph?searchtype=author&query=Finkbeiner%2C+D">Douglas Finkbeiner</a>, <a href="/search/astro-ph?searchtype=author&query=Anand%2C+A">Abhijeet Anand</a>, <a href="/search/astro-ph?searchtype=author&query=Ashby%2C+M">Matthew Ashby</a>, <a href="/search/astro-ph?searchtype=author&query=Bahr-Kalus%2C+B">Benedict Bahr-Kalus</a>, <a href="/search/astro-ph?searchtype=author&query=Beaton%2C+R">Rachel Beaton</a>, <a href="/search/astro-ph?searchtype=author&query=Behera%2C+J">Jayashree Behera</a>, <a href="/search/astro-ph?searchtype=author&query=Bell%2C+E+F">Eric F. Bell</a>, <a href="/search/astro-ph?searchtype=author&query=Bellm%2C+E+C">Eric C Bellm</a> , et al. (184 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="2306.11784v1-abstract-short" style="display: inline;"> The Nancy Grace Roman Space Telescope is capable of delivering an unprecedented all-sky, high-spatial resolution, multi-epoch infrared map to the astronomical community. This opportunity arises in the midst of numerous ground- and space-based surveys that will provide extensive spectroscopy and imaging together covering the entire sky (such as Rubin/LSST, Euclid, UNIONS, SPHEREx, DESI, SDSS-V, GAL… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.11784v1-abstract-full').style.display = 'inline'; document.getElementById('2306.11784v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.11784v1-abstract-full" style="display: none;"> The Nancy Grace Roman Space Telescope is capable of delivering an unprecedented all-sky, high-spatial resolution, multi-epoch infrared map to the astronomical community. This opportunity arises in the midst of numerous ground- and space-based surveys that will provide extensive spectroscopy and imaging together covering the entire sky (such as Rubin/LSST, Euclid, UNIONS, SPHEREx, DESI, SDSS-V, GALAH, 4MOST, WEAVE, MOONS, PFS, UVEX, NEO Surveyor, etc.). Roman can uniquely provide uniform high-spatial-resolution (~0.1 arcsec) imaging over the entire sky, vastly expanding the science reach and precision of all of these near-term and future surveys. This imaging will not only enhance other surveys, but also facilitate completely new science. By imaging the full sky over two epochs, Roman can measure the proper motions for stars across the entire Milky Way, probing 100 times fainter than Gaia out to the very edge of the Galaxy. Here, we propose NANCY: a completely public, all-sky survey that will create a high-value legacy dataset benefiting innumerable ongoing and forthcoming studies of the universe. NANCY is a pure expression of Roman's potential: it images the entire sky, at high spatial resolution, in a broad infrared bandpass that collects as many photons as possible. The majority of all ongoing astronomical surveys would benefit from incorporating observations of NANCY into their analyses, whether these surveys focus on nearby stars, the Milky Way, near-field cosmology, or the broader universe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.11784v1-abstract-full').style.display = 'none'; document.getElementById('2306.11784v1-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> 20 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Submitted to the call for white papers for the Roman Core Community Survey (June 16th, 2023), and to the Bulletin of the AAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.05086">arXiv:2306.05086</a> <span> [<a href="https://arxiv.org/pdf/2306.05086">pdf</a>, <a href="https://arxiv.org/format/2306.05086">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> </div> </div> <p class="title is-5 mathjax"> Beyond Gaia DR3: Tracing the [$伪$/M]-[M/H] bimodality from the inner to the outer Milky Way disc with Gaia-RVS and convolutional neural networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">G. Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=Nepal%2C+S">S. Nepal</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">S. Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Traven%2C+G">G. Traven</a>, <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">A. B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">M. Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=Fournier%2C+Y">Y. Fournier</a>, <a href="/search/astro-ph?searchtype=author&query=Vallenari%2C+A">A. Vallenari</a>, <a href="/search/astro-ph?searchtype=author&query=Youakim%2C+K">K. Youakim</a>, <a href="/search/astro-ph?searchtype=author&query=Bergemann%2C+M">M. Bergemann</a>, <a href="/search/astro-ph?searchtype=author&query=M%C3%A9sz%C3%A1ros%2C+S">S. M茅sz谩ros</a>, <a href="/search/astro-ph?searchtype=author&query=Lucatello%2C+S">S. Lucatello</a>, <a href="/search/astro-ph?searchtype=author&query=Sordo%2C+R">R. Sordo</a>, <a href="/search/astro-ph?searchtype=author&query=Fabbro%2C+S">S. Fabbro</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Tautvai%C5%A1ien%C4%97%2C+G">G. Tautvai拧ien臈</a>, <a href="/search/astro-ph?searchtype=author&query=Mikolaitis%2C+%C5%A0">艩. Mikolaitis</a>, <a href="/search/astro-ph?searchtype=author&query=Montalb%C3%A1n%2C+J">J. Montalb谩n</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="2306.05086v2-abstract-short" style="display: inline;"> In June 2022, Gaia DR3 has provided the astronomy community with about one million spectra from the Radial Velocity Spectrometer (RVS) covering the CaII triplet region. However, one-third of the published spectra have 15<S/N<25 per pixel such that they pose problems for classical spectral analysis pipelines, and therefore, alternative ways to tap into these large datasets need to be devised. We ai… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05086v2-abstract-full').style.display = 'inline'; document.getElementById('2306.05086v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.05086v2-abstract-full" style="display: none;"> In June 2022, Gaia DR3 has provided the astronomy community with about one million spectra from the Radial Velocity Spectrometer (RVS) covering the CaII triplet region. However, one-third of the published spectra have 15<S/N<25 per pixel such that they pose problems for classical spectral analysis pipelines, and therefore, alternative ways to tap into these large datasets need to be devised. We aim to leverage the versatility and capabilities of machine learning techniques for supercharged stellar parametrisation by combining Gaia-RVS spectra with the full set of Gaia products and high-resolution, high-quality ground-based spectroscopic reference datasets. We developed a hybrid convolutional neural network (CNN) that combines the Gaia DR3 RVS spectra, photometry (G, G_BP, G_RP), parallaxes, and XP coefficients to derive atmospheric parameters (Teff, log(g) as well as overall [M/H]) and chemical abundances ([Fe/H] and [伪/M]). We trained the CNN with a high-quality training sample based on APOGEE DR17 labels. With this CNN, we derived homogeneous atmospheric parameters and abundances for 886080 RVS stars that show remarkable precision and accuracy compared to external datasets (such as GALAH and asteroseismology). The CNN is robust against noise in the RVS data, and we derive very precise labels down to S/N=15. We managed to characterise the [伪/M]-[M/H] bimodality from the inner regions to the outer parts of the Milky Way, which has never been done using RVS spectra or similar datasets. This work is the first to combine machine learning with such diverse datasets and paves the way for large-scale machine learning analysis of Gaia-RVS spectra from future data releases. Large, high-quality datasets can be optimally combined thanks to the CNN, thereby realising the full power of spectroscopy, astrometry, and photometry. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05086v2-abstract-full').style.display = 'none'; document.getElementById('2306.05086v2-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">v1</span> submitted 8 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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 A&A. Catalog available online soon. Please contact the corresponding authors for any inquiry on the catalog or ML codes. 26 pages, 29 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/2305.13759">arXiv:2305.13759</a> <span> [<a href="https://arxiv.org/pdf/2305.13759">pdf</a>, <a href="https://arxiv.org/format/2305.13759">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="Cosmology and Nongalactic Astrophysics">astro-ph.CO</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/stad1503">10.1093/mnras/stad1503 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The impact of early massive mergers on the chemical evolution of Milky Way-like galaxies: insights from NIHAO-UHD simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Obreja%2C+A">Aura Obreja</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Yuxi"> Yuxi</a>, <a href="/search/astro-ph?searchtype=author&query=Lu"> Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Macci%C3%B2%2C+A+V">Andrea V. Macci貌</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="2305.13759v2-abstract-short" style="display: inline;"> Recent observations of the Milky Way (MW) found an unexpected steepening of the star-forming gas metallicity gradient around the time of the Gaia-Sausage-Enceladus (GSE) merger event. Here we investigate the influence of early ($t_{\mathrm{merger}}\lesssim5$ Gyr) massive ($M_{\mathrm{gas}}^{\mathrm{merger}}/M_{\mathrm{gas}}^{\mathrm{main}}(t_{\mathrm{merger}})\gtrsim10\%$) merger events such as th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.13759v2-abstract-full').style.display = 'inline'; document.getElementById('2305.13759v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.13759v2-abstract-full" style="display: none;"> Recent observations of the Milky Way (MW) found an unexpected steepening of the star-forming gas metallicity gradient around the time of the Gaia-Sausage-Enceladus (GSE) merger event. Here we investigate the influence of early ($t_{\mathrm{merger}}\lesssim5$ Gyr) massive ($M_{\mathrm{gas}}^{\mathrm{merger}}/M_{\mathrm{gas}}^{\mathrm{main}}(t_{\mathrm{merger}})\gtrsim10\%$) merger events such as the Gaia-Sausage Enceladus merger in the MW on the evolution of the cold gas metallicity gradient. We use the NIHAO-UHD suite of cosmological hydrodynamical simulations of MW-mass galaxies to study the frequency of massive early mergers and their detailed impact on the morphology and chemistry of the gaseous disks. We find a strong steepening of the metallicity gradient at early times for all four galaxies in our sample which is caused by a sudden increase in the cold gas disk size (up to a factor of 2) in combination with the supply of un-enriched gas ($\sim0.75$ dex lower compared to the main galaxy) by the merging dwarf galaxies. The mergers mostly affect the galaxy outskirts and lead to an increase in cold gas surface density of up to 200% outside of $\sim8$ kpc. The addition of un-enriched gas breaks the self-similar enrichment of the inter-stellar-medium and causes a dilution of the cold gas in the outskirts of the galaxies. The accreted stars and the ones formed later out of the accreted gas inhabit distinct tracks offset to lower [$伪$/Fe] and [Fe/H] values compared to the main galaxy's stars. We find that such mergers can contribute significantly to the formation of a second, low-$伪$ sequence as is observed in the MW. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.13759v2-abstract-full').style.display = 'none'; document.getElementById('2305.13759v2-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 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">13 pages, 10 figures, accepted 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/2305.13378">arXiv:2305.13378</a> <span> [<a href="https://arxiv.org/pdf/2305.13378">pdf</a>, <a href="https://arxiv.org/format/2305.13378">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> </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/stad1573">10.1093/mnras/stad1573 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Unveiling the time evolution of chemical abundances across the Milky Way disk with APOGEE </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">Friedrich Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">Guillaume Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Cunha%2C+K">Katia Cunha</a>, <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A">Anna Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Nitschelm%2C+C">Christian Nitschelm</a>, <a href="/search/astro-ph?searchtype=author&query=Meszaros%2C+S">Szabolcs Meszaros</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">Roelof S. de Jong</a>, <a href="/search/astro-ph?searchtype=author&query=Nepal%2C+S">Samir Nepal</a>, <a href="/search/astro-ph?searchtype=author&query=Lane%2C+R+R">Richard R. Lane</a>, <a href="/search/astro-ph?searchtype=author&query=Sobeck%2C+J">Jennifer Sobeck</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="2305.13378v2-abstract-short" style="display: inline;"> Chemical abundances are an essential tool in untangling the Milky Way's enrichment history. However, the evolution of the interstellar medium abundance gradient with cosmic time is lost as a result of radial mixing processes. For the first time, we quantify the evolution of many observational abundances across the Galactic disk as a function of lookback time and birth radius, $R_\text{birth}$. Usi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.13378v2-abstract-full').style.display = 'inline'; document.getElementById('2305.13378v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.13378v2-abstract-full" style="display: none;"> Chemical abundances are an essential tool in untangling the Milky Way's enrichment history. However, the evolution of the interstellar medium abundance gradient with cosmic time is lost as a result of radial mixing processes. For the first time, we quantify the evolution of many observational abundances across the Galactic disk as a function of lookback time and birth radius, $R_\text{birth}$. Using an empirical approach, we derive $R_\text{birth}$ estimates for 145,447 APOGEE DR17 red giant disk stars, based solely on their ages and [Fe/H]. We explore the detailed evolution of 6 abundances (Mg, Ca ($伪$), Mn (iron-peak), Al, C (light), Ce (s-process)) across the Milky Way disk using 87,426 APOGEE DR17 red giant stars. We discover that the interstellar medium had three fluctuations in the metallicity gradient $\sim 9$, $\sim 6$, and $\sim4$ Gyr ago. The first coincides with the end of high-$伪$ sequence formation around the time of the Gaia-Sausage-Enceladus disruption, while the others are likely related to passages of the Sagittarius dwarf galaxy. A clear distinction is found between present-day observed radial gradients with age and the evolution with lookback time for both [X/Fe] and [X/H], resulting from the significant flattening and inversion in old populations due to radial migration. We find the [Fe/H]--[$伪$/Fe] bimodality is also seen as a separation in the $R_\text{birth}$--[X/Fe] plane for the light and $伪$-elements. Our results recover the chemical enrichment of the Galactic disk over the past 12 Gyr, providing tight constraints on Galactic disk chemical evolution models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.13378v2-abstract-full').style.display = 'none'; document.getElementById('2305.13378v2-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 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 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/2304.08276">arXiv:2304.08276</a> <span> [<a href="https://arxiv.org/pdf/2304.08276">pdf</a>, <a href="https://arxiv.org/format/2304.08276">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> </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/10.1051/0004-6361/202346666">10.1051/0004-6361/202346666 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spectroscopic age estimates for APOGEE red-giant stars: Precise spatial and kinematic trends with age in the Galactic disc </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">F. Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Gispert%2C+P">P. Gispert</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">B. Ratcliffe</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Nepal%2C+S">S. Nepal</a>, <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">A. B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Amarante%2C+J+A+S">J. A. S. Amarante</a>, <a href="/search/astro-ph?searchtype=author&query=Antoja%2C+T">T. Antoja</a>, <a href="/search/astro-ph?searchtype=author&query=Casali%2C+G">G. Casali</a>, <a href="/search/astro-ph?searchtype=author&query=Casamiquela%2C+L">L. Casamiquela</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">A. Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Miglio%2C+A">A. Miglio</a>, <a href="/search/astro-ph?searchtype=author&query=Perottoni%2C+H">H. Perottoni</a>, <a href="/search/astro-ph?searchtype=author&query=Schultheis%2C+M">M. Schultheis</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="2304.08276v3-abstract-short" style="display: inline;"> Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median statistical uncertainty of 17%. To this end, we use the supervised machine learning technique XGBoost, trained on a high-quality dataset of 3060 red-giant and red-c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08276v3-abstract-full').style.display = 'inline'; document.getElementById('2304.08276v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.08276v3-abstract-full" style="display: none;"> Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median statistical uncertainty of 17%. To this end, we use the supervised machine learning technique XGBoost, trained on a high-quality dataset of 3060 red-giant and red-clump stars with asteroseismic ages observed by both APOGEE and Kepler. After verifying the obtained age estimates with independent catalogues, we investigate some of the classical chemical, positional, and kinematic relationships of the stars as a function of their age. We find a very clear imprint of the outer-disc flare in the age maps and confirm the recently found split in the local age-metallicity relation. We present new and precise measurements of the Galactic radial metallicity gradient in small age bins between 0.5 and 12 Gyr, confirming a steeper metallicity gradient for $\sim2-5$ Gyr old populations and a subsequent flattening for older populations mostly produced by radial migration. In addition, we analyse the dispersion about the abundance gradient as a function of age. We find a clear power-law trend (with an exponent $尾\approx0.15$) for this relation, indicating a relatively smooth radial migration history in the Galactic disc over the past $7-9$ Gyr. Departures from this power law may possibly be related to the Gaia Enceladus merger and passages of the Sagittarius dSph galaxy. Finally, we confirm previous measurements showing a steepening in the age-velocity dispersion relation at around $\sim9$ Gyr, but now extending it over a large extent of the Galactic disc (5 kpc $<R_{\rm Gal}<13$ kpc). [Abridged] <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08276v3-abstract-full').style.display = 'none'; document.getElementById('2304.08276v3-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">v1</span> submitted 17 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">16 pages + 5 pages appendix, accepted for publication in A&A. Data and analysis code available at https://github.com/fjaellet/xgboost_chem_ages</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 678, A158 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.09926">arXiv:2303.09926</a> <span> [<a href="https://arxiv.org/pdf/2303.09926">pdf</a>, <a href="https://arxiv.org/format/2303.09926">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="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/10.1051/0004-6361/202245399">10.1051/0004-6361/202245399 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> StarHorse results for spectroscopic surveys + Gaia DR3: Chrono-chemical populations in the solar vicinity, the genuine thick disk, and young-alpha rich stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">Anna B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">Friedrich Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">Cristina Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">Arman Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Santiago%2C+B+X">Basilio X. Santiago</a>, <a href="/search/astro-ph?searchtype=author&query=Nepal%2C+S">Samir Nepal</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Gallart%2C+C">Carme Gallart</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">Marica Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=Ponte%2C+M+D">Marina Dal Ponte</a>, <a href="/search/astro-ph?searchtype=author&query=Barbuy%2C+B">Beatriz Barbuy</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A9rez-Villegas%2C+A">Angeles P茅rez-Villegas</a>, <a href="/search/astro-ph?searchtype=author&query=Masseron%2C+T">Thomas Masseron</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez-Trincado%2C+J+G">Jos茅 G. Fern谩ndez-Trincado</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez-Alvar%2C+E">Emma Fern谩ndez-Alvar</a>, <a href="/search/astro-ph?searchtype=author&query=Lane%2C+R+R">Richard R. Lane</a>, <a href="/search/astro-ph?searchtype=author&query=Nitschelm%2C+C">Christian Nitschelm</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="2303.09926v1-abstract-short" style="display: inline;"> The Gaia mission has provided an invaluable wealth of astrometric data for more than a billion stars in our Galaxy. The synergy between Gaia astrometry, photometry, and spectroscopic surveys give us comprehensive information about the Milky Way. Using the Bayesian isochrone-fitting code StarHorse, we derive distances and extinctions for more than 10 million unique stars observed by both Gaia Data… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.09926v1-abstract-full').style.display = 'inline'; document.getElementById('2303.09926v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.09926v1-abstract-full" style="display: none;"> The Gaia mission has provided an invaluable wealth of astrometric data for more than a billion stars in our Galaxy. The synergy between Gaia astrometry, photometry, and spectroscopic surveys give us comprehensive information about the Milky Way. Using the Bayesian isochrone-fitting code StarHorse, we derive distances and extinctions for more than 10 million unique stars observed by both Gaia Data Release 3 as well as public spectroscopic surveys: GALAH DR3, LAMOST DR7 LRS, LAMOST DR7 MRS, APOGEE DR17, RAVE DR6, SDSS DR12 (optical spectra from BOSS and SEGUE), Gaia-ESO DR5 survey, and Gaia RVS part of Gaia DR3 release. We use StarHorse for the first time to derive stellar age for main-sequence turnoff and subgiant branch stars (MSTO-SGB), around 2.5 million stars with age uncertainties typically around 30%, 15% for only SGB stars, depending on the resolution of the survey. With the derived ages in hand, we investigate the chemical-age relations. In particular, the $伪$ and neutron-capture element ratios versus age in the solar neighbourhood show trends similar to previous works, validating our ages. We use the chemical abundances from local subgiant samples of GALAH DR3, APOGEE DR17 and LAMOST MRS DR7 to map groups with similar chemical compositions and StarHorse ages with the dimensionality reduction technique t-SNE and the clustering algorithm HDBSCAN. We identify three distinct groups in all three samples. Their kinematic properties confirm them to be the genuine chemical thick disk, the thin disk and a considerable number of young alpha-rich stars. We confirm that the genuine thick disk's kinematics and age properties are radically different from those of the thin disk and compatible with high-redshift (z$\approx$2) star-forming disks with high dispersion velocities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.09926v1-abstract-full').style.display = 'none'; document.getElementById('2303.09926v1-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> 17 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">27 pages, 19 figures. Accepted for publication in Astronomy & Astrophysics. Catalogues can be downloaded at https://data.aip.de/</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 673, A155 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.09621">arXiv:2301.09621</a> <span> [<a href="https://arxiv.org/pdf/2301.09621">pdf</a>, <a href="https://arxiv.org/format/2301.09621">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> </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/stad275">10.1093/mnras/stad275 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The vertical structure of the spiral galaxy NGC 3501: first stages of the formation of a thin metal-rich disc </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sattler%2C+N">Natascha Sattler</a>, <a href="/search/astro-ph?searchtype=author&query=Pinna%2C+F">Francesca Pinna</a>, <a href="/search/astro-ph?searchtype=author&query=Neumayer%2C+N">Nadine Neumayer</a>, <a href="/search/astro-ph?searchtype=author&query=Falc%C3%B3n-Barroso%2C+J">Jesus Falc贸n-Barroso</a>, <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">Marie Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Gadotti%2C+D+A">Dimitri A. Gadotti</a>, <a href="/search/astro-ph?searchtype=author&query=van+de+Ven%2C+G">Glenn van de Ven</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</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="2301.09621v1-abstract-short" style="display: inline;"> We trace the evolution of the edge-on spiral galaxy NGC 3501, making use of its stellar populations extracted from deep integral-field spectroscopy MUSE observations. We present stellar kinematic and population maps, as well as the star formation history, of the south-western half of the galaxy. The derived maps of the stellar line-of-sight velocity and velocity dispersion are quite regular, show… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.09621v1-abstract-full').style.display = 'inline'; document.getElementById('2301.09621v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.09621v1-abstract-full" style="display: none;"> We trace the evolution of the edge-on spiral galaxy NGC 3501, making use of its stellar populations extracted from deep integral-field spectroscopy MUSE observations. We present stellar kinematic and population maps, as well as the star formation history, of the south-western half of the galaxy. The derived maps of the stellar line-of-sight velocity and velocity dispersion are quite regular, show disc-like rotation, and no other structural component of the galaxy. However, maps of the stellar populations exhibit structures in the mass-weighted and light-weighted age, total metallicity and [Mg/Fe] abundance. These maps indicate that NGC 3501 is a young galaxy, consisting mostly of stars with ages between 2 to 8 Gyr. Also, they show a thicker more extended structure that is metal-poor and $伪$-rich, and another inner metal-rich and $伪$-poor one with smaller radial extension. While previous studies revealed that NGC 3501 shows only one morphological disc component in its vertical structure, we divided the galaxy into two regions: an inner metal-rich midplane and a metal-poor thicker envelope. Comparing the star formation history of the inner thinner metal-rich disc and the thicker metal-poor disc, we see that the metal-rich component evolved more steadily, while the metal-poor one experienced several bursts of star formation. We propose this spiral galaxy is being observed in an early evolutionary phase, with a thicker disc already in place and an inner thin disc in an early formation stage. So we are probably witnessing the birth of a future massive thin disc, continuously growing embedded in a preexisting thicker disc. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.09621v1-abstract-full').style.display = 'none'; document.getElementById('2301.09621v1-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 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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, 12 figures. Accepted for publication in 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/2212.04515">arXiv:2212.04515</a> <span> [<a href="https://arxiv.org/pdf/2212.04515">pdf</a>, <a href="https://arxiv.org/format/2212.04515">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> </div> </div> <p class="title is-5 mathjax"> There is No Place Like Home -- Finding Birth Radii of Stars in the Milky Way </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lu%2C+Y">Yuxi Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N">Noam Libeskind</a>, <a href="/search/astro-ph?searchtype=author&query=Cescutti%2C+G">Gabriele Cescutti</a>, <a href="/search/astro-ph?searchtype=author&query=Freeman%2C+K+C">Ken C. Freeman</a>, <a href="/search/astro-ph?searchtype=author&query=Ratcliffe%2C+B">Bridget Ratcliffe</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="2212.04515v3-abstract-short" style="display: inline;"> Stars move away from their birthplaces over time via a process known as radial migration, which blurs chemo-kinematic relations used for reconstructing the Milky Way (MW) formation history. To understand the true time evolution of the MW, one needs to take into account the effects of this process. We show that stellar birth radii can be derived directly from the data with minimum prior assumptions… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.04515v3-abstract-full').style.display = 'inline'; document.getElementById('2212.04515v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.04515v3-abstract-full" style="display: none;"> Stars move away from their birthplaces over time via a process known as radial migration, which blurs chemo-kinematic relations used for reconstructing the Milky Way (MW) formation history. To understand the true time evolution of the MW, one needs to take into account the effects of this process. We show that stellar birth radii can be derived directly from the data with minimum prior assumptions on the Galactic enrichment history. This is done by first recovering the time evolution of the stellar birth metallicity gradient, $d\mathrm{[Fe/H]}(R, 蟿)/dR$, through its inverse relation to the metallicity range as a function of age today, allowing us to place any star with age and metallicity measurements back to its birthplace, $R_b$. Applying our method to a large, high-precision data set of MW disk subgiant stars, we find a steepening of the birth metallicity gradient from 11 to 8 Gyr ago, which coincides with the time of the last massive merger, Gaia-Sausage-Enceladus (GSE). This transition appears to play a major role in shaping both the age-metallicity relation and the bimodality in the [$伪$/Fe]-[Fe/H] plane. By dissecting the disk into mono-$R_b$ populations, clumps in the low-[$伪$/Fe] sequence appear, which are not seen in the total sample and coincide in time with known star-formation bursts, possibly associated with the Sagittarius Dwarf Galaxy. We estimated that the Sun was born at $4.5\pm 0.4$~kpc from the Galactic center. Our $R_b$ estimates provide the missing piece needed to recover the Milky Way formation history. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.04515v3-abstract-full').style.display = 'none'; document.getElementById('2212.04515v3-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.14576">arXiv:2209.14576</a> <span> [<a href="https://arxiv.org/pdf/2209.14576">pdf</a>, <a href="https://arxiv.org/format/2209.14576">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> </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/10.1051/0004-6361/202142581">10.1051/0004-6361/202142581 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> ISM metallicity variations across spiral arms in disk galaxies: the impact of local enrichment and gas migration in the presence of radial metallicity gradient </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Sivkova%2C+E">Evgenia Sivkova</a>, <a href="/search/astro-ph?searchtype=author&query=Saburova%2C+A">Anna Saburova</a>, <a href="/search/astro-ph?searchtype=author&query=Vasiliev%2C+E">Evgenii Vasiliev</a>, <a href="/search/astro-ph?searchtype=author&query=Shustov%2C+B">Boris Shustov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Walcher%2C+C+J">C. Jakob Walcher</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="2209.14576v1-abstract-short" style="display: inline;"> Chemical abundance variations in the ISM provide important information about the galactic evolution, star-formation and enrichment histories. Recent observations of disk galaxies suggest that if large-scale azimuthal metallicity variations appear in the ISM, they are linked to the spiral arms. In this work, using a set of chemodynamical simulations of the Milky Way-like spiral galaxies, we quantif… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.14576v1-abstract-full').style.display = 'inline'; document.getElementById('2209.14576v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.14576v1-abstract-full" style="display: none;"> Chemical abundance variations in the ISM provide important information about the galactic evolution, star-formation and enrichment histories. Recent observations of disk galaxies suggest that if large-scale azimuthal metallicity variations appear in the ISM, they are linked to the spiral arms. In this work, using a set of chemodynamical simulations of the Milky Way-like spiral galaxies, we quantify the impact of gas radial motions~(migration) in the presence of a pre-existing radial metallicity gradient and the local ISM enrichment on both global and local variations of the mean ISM metallicity in the vicinity of the spiral arms. In all the models, we find the scatter of the gas metallicity of \approx0.04-0.06 dex at a given galactocentric distance. On large scales, we observe the presence of spiral-like metallicity patterns in the ISM which are more prominent in models with the radial metallicity gradient. However, in our simulations, the morphology of the large-scale ISM metallicity distributions significantly differs from the spiral arms structure in stellar/gas components resulting in both positive and negative residual~(after subtraction of the radial gradient) metallicity trends along spiral arms. We discuss the correlations of the residual ISM metallicity values with the star formation rate, gas kinematics and offset to the spiral arms, concluding that the presence of a radial metallicity gradient is essential for the azimuthal variations of metallicity. At the same time, the local enrichment alone is unlikely to drive systematic variations of the metallicity across the spirals. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.14576v1-abstract-full').style.display = 'none'; document.getElementById('2209.14576v1-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> 29 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">A&A in press</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.01738">arXiv:2209.01738</a> <span> [<a href="https://arxiv.org/pdf/2209.01738">pdf</a>, <a href="https://arxiv.org/format/2209.01738">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/10.1051/0004-6361/202243593">10.1051/0004-6361/202243593 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Stellar Population Astrophysics (SPA) with the TNG. alpha-elements, lithium, sodium and aluminum in 16 open clusters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+R">R. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Lucatello%2C+S">S. Lucatello</a>, <a href="/search/astro-ph?searchtype=author&query=Bragaglia%2C+A">A. Bragaglia</a>, <a href="/search/astro-ph?searchtype=author&query=Alonso-Santiago%2C+J">J. Alonso-Santiago</a>, <a href="/search/astro-ph?searchtype=author&query=Andreuzzi%2C+G">G. Andreuzzi</a>, <a href="/search/astro-ph?searchtype=author&query=Casali%2C+G">G. Casali</a>, <a href="/search/astro-ph?searchtype=author&query=Carrera%2C+R">R. Carrera</a>, <a href="/search/astro-ph?searchtype=author&query=Carretta%2C+E">E. Carretta</a>, <a href="/search/astro-ph?searchtype=author&query=Orazi%2C+V+D">V. D Orazi</a>, <a href="/search/astro-ph?searchtype=author&query=Frasca%2C+A">A. Frasca</a>, <a href="/search/astro-ph?searchtype=author&query=Fu%2C+X">X. Fu</a>, <a href="/search/astro-ph?searchtype=author&query=Magrini%2C+L">L. Magrini</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Origlia%2C+L">L. Origlia</a>, <a href="/search/astro-ph?searchtype=author&query=Spina%2C+L">L. Spina</a>, <a href="/search/astro-ph?searchtype=author&query=Vallenari%2C+A">A. Vallenari</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="2209.01738v1-abstract-short" style="display: inline;"> Exploring the Galactic chemical evolution and enrichment scenarios with open clusters allows us to understand the history of the Milky Way disk. High-resolution spectra of OCs are a crucial tool, as they provide precise chemical information, to combine with precise distances and ages. The aim of the Stellar Population Astrophysics project is to derive homogeneous and accurate comprehensive chemica… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.01738v1-abstract-full').style.display = 'inline'; document.getElementById('2209.01738v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.01738v1-abstract-full" style="display: none;"> Exploring the Galactic chemical evolution and enrichment scenarios with open clusters allows us to understand the history of the Milky Way disk. High-resolution spectra of OCs are a crucial tool, as they provide precise chemical information, to combine with precise distances and ages. The aim of the Stellar Population Astrophysics project is to derive homogeneous and accurate comprehensive chemical characterization of a number of poorly studied OCs.Using the HARPS-N echelle spectrograph at the Telescopio Nazionale Galileo, we obtained high-resolution spectra of giant stars in 18 OCs, 16 of which are chemically characterized for the first time, and two of which are well studied for comparison. The OCs in this sample have ages from a few tens of Myr to 4 Gyr, with a prevalence of young clusters. We already presented the radial velocities and atmospheric parameters for them in a previous SPA paper. Here, we present results for the alpha-elements O, and the light elements, all determined by the equivalent width method. We also measured Li abundance through the synthesis method.We discuss the behaviors of lithium, sodium and aluminum in the context of stellar evolution. We study the radial, vertical, and age trends for the measured abundance ratios in a sample that combines our results and recent literature for OCs, finding significant gradients only for [Mg/Fe] and [Ca/Fe] in all cases. Finally,we compare O and Mg in the combined sample with chemo-dynamical models, finding a good agreement for intermediate-age and old clusters. There is a sharp increase in the abundance ratios measured among very young clusters, accompanied by a poorer fit with the models for O and Mg, likely related to the inadequacy of traditional model atmospheres and methods in the derivation of atmospheric parameters and abundance ratios for stars of such young ages <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.01738v1-abstract-full').style.display = 'none'; document.getElementById('2209.01738v1-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> 4 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">Journal ref:</span> A&A 667, A103 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.05432">arXiv:2208.05432</a> <span> [<a href="https://arxiv.org/pdf/2208.05432">pdf</a>, <a href="https://arxiv.org/format/2208.05432">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="Earth and Planetary Astrophysics">astro-ph.EP</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/10.1051/0004-6361/202243134">10.1051/0004-6361/202243134 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Gilmore%2C+G">G. Gilmore</a>, <a href="/search/astro-ph?searchtype=author&query=Randich%2C+S">S. Randich</a>, <a href="/search/astro-ph?searchtype=author&query=Worley%2C+C+C">C. C. Worley</a>, <a href="/search/astro-ph?searchtype=author&query=Hourihane%2C+A">A. Hourihane</a>, <a href="/search/astro-ph?searchtype=author&query=Gonneau%2C+A">A. Gonneau</a>, <a href="/search/astro-ph?searchtype=author&query=Sacco%2C+G+G">G. G. Sacco</a>, <a href="/search/astro-ph?searchtype=author&query=Lewis%2C+J+R">J. R. Lewis</a>, <a href="/search/astro-ph?searchtype=author&query=Magrini%2C+L">L. Magrini</a>, <a href="/search/astro-ph?searchtype=author&query=Francois%2C+P">P. Francois</a>, <a href="/search/astro-ph?searchtype=author&query=Jeffries%2C+R+D">R. D. Jeffries</a>, <a href="/search/astro-ph?searchtype=author&query=Koposov%2C+S+E">S. E. Koposov</a>, <a href="/search/astro-ph?searchtype=author&query=Bragaglia%2C+A">A. Bragaglia</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+E+J">E. J. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+C+A">C. Allende Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Blomme%2C+R">R. Blomme</a>, <a href="/search/astro-ph?searchtype=author&query=Korn%2C+A+J">A. J. Korn</a>, <a href="/search/astro-ph?searchtype=author&query=Lanzafame%2C+A+C">A. C. Lanzafame</a>, <a href="/search/astro-ph?searchtype=author&query=Pancino%2C+E">E. Pancino</a>, <a href="/search/astro-ph?searchtype=author&query=Recio-Blanco%2C+A">A. Recio-Blanco</a>, <a href="/search/astro-ph?searchtype=author&query=Smiljanic%2C+R">R. Smiljanic</a>, <a href="/search/astro-ph?searchtype=author&query=Van+Eck%2C+S">S. Van Eck</a>, <a href="/search/astro-ph?searchtype=author&query=Zwitter%2C+T">T. Zwitter</a>, <a href="/search/astro-ph?searchtype=author&query=Bensby%2C+T">T. Bensby</a>, <a href="/search/astro-ph?searchtype=author&query=Flaccomio%2C+E">E. Flaccomio</a>, <a href="/search/astro-ph?searchtype=author&query=Irwin%2C+M+J">M. J. Irwin</a> , et al. (143 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="2208.05432v1-abstract-short" style="display: inline;"> The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to obtain astrophysical parameters and elemental abundances for 100,000 stars, including large representative samples of the stellar populations in the Galaxy, and a well-defined sample of 60 (plus 20 archive) open clusters. We provide internally consistent results calibrated on benchmark stars and star clusters, extending a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.05432v1-abstract-full').style.display = 'inline'; document.getElementById('2208.05432v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.05432v1-abstract-full" style="display: none;"> The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to obtain astrophysical parameters and elemental abundances for 100,000 stars, including large representative samples of the stellar populations in the Galaxy, and a well-defined sample of 60 (plus 20 archive) open clusters. We provide internally consistent results calibrated on benchmark stars and star clusters, extending across a very wide range of abundances and ages. This provides a legacy data set of intrinsic value, and equally a large wide-ranging dataset that is of value for homogenisation of other and future stellar surveys and Gaia's astrophysical parameters. This article provides an overview of the survey methodology, the scientific aims, and the implementation, including a description of the data processing for the GIRAFFE spectra. A companion paper (arXiv:2206.02901) introduces the survey results. Gaia-ESO aspires to quantify both random and systematic contributions to measurement uncertainties. Thus all available spectroscopic analysis techniques are utilised, each spectrum being analysed by up to several different analysis pipelines, with considerable effort being made to homogenise and calibrate the resulting parameters. We describe here the sequence of activities up to delivery of processed data products to the ESO Science Archive Facility for open use. The Gaia-ESO Survey obtained 202,000 spectra of 115,000 stars using 340 allocated VLT nights between December 2011 and January 2018 from GIRAFFE and UVES. The full consistently reduced final data set of spectra was released through the ESO Science Archive Facility in late 2020, with the full astrophysical parameters sets following in 2022. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.05432v1-abstract-full').style.display = 'none'; document.getElementById('2208.05432v1-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 August, 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">38 pages. A&A in press</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 666, A120 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.13650">arXiv:2206.13650</a> <span> [<a href="https://arxiv.org/pdf/2206.13650">pdf</a>, <a href="https://arxiv.org/format/2206.13650">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/10.3847/1538-3881/ac7ce5">10.3847/1538-3881/ac7ce5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Open Cluster Chemical Abundances and Mapping Survey: VI. Galactic Chemical Gradient Analysis from APOGEE DR17 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Myers%2C+N">Natalie Myers</a>, <a href="/search/astro-ph?searchtype=author&query=Donor%2C+J">John Donor</a>, <a href="/search/astro-ph?searchtype=author&query=Spoo%2C+T">Taylor Spoo</a>, <a href="/search/astro-ph?searchtype=author&query=Frinchaboy%2C+P+M">Peter M. Frinchaboy</a>, <a href="/search/astro-ph?searchtype=author&query=Cunha%2C+K">Katia Cunha</a>, <a href="/search/astro-ph?searchtype=author&query=Price-Whelan%2C+A+M">Adrian M. Price-Whelan</a>, <a href="/search/astro-ph?searchtype=author&query=Majewski%2C+S+R">Steven R. Majewski</a>, <a href="/search/astro-ph?searchtype=author&query=Beaton%2C+R+L">Rachael L. Beaton</a>, <a href="/search/astro-ph?searchtype=author&query=Zasowski%2C+G">Gail Zasowski</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Connell%2C+J">Julia O'Connell</a>, <a href="/search/astro-ph?searchtype=author&query=Ray%2C+A+E">Amy E. Ray</a>, <a href="/search/astro-ph?searchtype=author&query=Bizyaev%2C+D">Dmitry Bizyaev</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">Cristina Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Garc%C3%ADa-Hern%C3%A1ndez%2C+D+A">D. A. Garc铆a-Hern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Geisler%2C+D">Doug Geisler</a>, <a href="/search/astro-ph?searchtype=author&query=J%C3%B6nsson%2C+H">Henrik J枚nsson</a>, <a href="/search/astro-ph?searchtype=author&query=Lane%2C+R+R">Richard R. Lane</a>, <a href="/search/astro-ph?searchtype=author&query=Longa-Pe%C3%B1a%2C+P">Pen茅lope Longa-Pe帽a</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Minniti%2C+D">Dante Minniti</a>, <a href="/search/astro-ph?searchtype=author&query=Nitschelm%2C+C">Christian Nitschelm</a>, <a href="/search/astro-ph?searchtype=author&query=Roman-Lopes%2C+A">A. Roman-Lopes</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="2206.13650v1-abstract-short" style="display: inline;"> The goal of the Open Cluster Chemical Abundances and Mapping (OCCAM) survey is to constrain key Galactic dynamic and chemical evolution parameters by the construction and analysis of a large, comprehensive, uniform data set of infrared spectra for stars in hundreds of open clusters. This sixth contribution from the OCCAM survey presents analysis of SDSS/APOGEE Data Release 17 (DR17) results for a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13650v1-abstract-full').style.display = 'inline'; document.getElementById('2206.13650v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.13650v1-abstract-full" style="display: none;"> The goal of the Open Cluster Chemical Abundances and Mapping (OCCAM) survey is to constrain key Galactic dynamic and chemical evolution parameters by the construction and analysis of a large, comprehensive, uniform data set of infrared spectra for stars in hundreds of open clusters. This sixth contribution from the OCCAM survey presents analysis of SDSS/APOGEE Data Release 17 (DR17) results for a sample of stars in 150 open clusters, 94 of which we designate to be "high quality'' based on the appearance of their color-magnitude diagram. We find the APOGEE DR17-derived [Fe/H] values to be in good agreement with those from previous high resolution spectroscopic open cluster abundance studies. Using a subset of the high quality sample, the Galactic abundance gradients were measured for 16 chemical elements, including [Fe/H], for both Galactocentric radius ($R_{GC}$) and guiding center radius ($R_{Guide}$). We find an overall Galactic [Fe/H] vs $R_{GC}$ gradient of $-0.073 \pm 0.002$ dex/kpc over the range of $6 < R_{GC} < 11.5$ kpc, and a similar gradient is found for [Fe/H] versus $R_{Guide}$. Significant Galactic abundance gradients are also noted for O, Mg, S, Ca, Mn, Na, Al, K and Ce. Our large sample additionally allows us to explore the evolution of the gradients in four age bins for the remaining 15 elements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13650v1-abstract-full').style.display = 'none'; document.getElementById('2206.13650v1-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">21 pages, 14 Figures, Astronomical Journal Accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.05491">arXiv:2206.05491</a> <span> [<a href="https://arxiv.org/pdf/2206.05491">pdf</a>, <a href="https://arxiv.org/format/2206.05491">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> </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/10.1051/0004-6361/202244234">10.1051/0004-6361/202244234 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The stellar halo in Local Group Hestia simulations III. Chemical abundance relations for accreted and in-situ stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N">Noam Libeskind</a>, <a href="/search/astro-ph?searchtype=author&query=Belokurov%2C+V">Vasily Belokurov</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+F+A">Facundo A. Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Grand%2C+R+J+J">Robert J. J. Grand</a>, <a href="/search/astro-ph?searchtype=author&query=Hoffman%2C+Y">Yehuda Hoffman</a>, <a href="/search/astro-ph?searchtype=author&query=Knebe%2C+A">Alexander Knebe</a>, <a href="/search/astro-ph?searchtype=author&query=Sorce%2C+J+G">Jenny G. Sorce</a>, <a href="/search/astro-ph?searchtype=author&query=Sparre%2C+M">Martin Sparre</a>, <a href="/search/astro-ph?searchtype=author&query=Tempel%2C+E">Elmo Tempel</a>, <a href="/search/astro-ph?searchtype=author&query=Vogelsberger%2C+M">Mark Vogelsberger</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="2206.05491v2-abstract-short" style="display: inline;"> Since the chemical abundances of stars are the fossil records of the physical conditions in galaxies, they provide the key information for recovering the assembly history of galaxies. In this work, we explore the chemo-chrono-kinematics of accreted and in-situ stars, by analyzing six M31/MW analogues from the HESTIA suite of cosmological hydrodynamics zoom-in simulations of the Local Group. We fou… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.05491v2-abstract-full').style.display = 'inline'; document.getElementById('2206.05491v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.05491v2-abstract-full" style="display: none;"> Since the chemical abundances of stars are the fossil records of the physical conditions in galaxies, they provide the key information for recovering the assembly history of galaxies. In this work, we explore the chemo-chrono-kinematics of accreted and in-situ stars, by analyzing six M31/MW analogues from the HESTIA suite of cosmological hydrodynamics zoom-in simulations of the Local Group. We found that the merger debris are chemically distinct from the survived dwarf galaxies. The mergers debris have abundances expected for stars originating from dwarfs that had their star formation activity quenched at early times. Accreted stellar haloes, including individual debris, reveal abundance gradients in the ELz, where the most metal-rich stars have formed in the inner parts of the disrupted systems before the merger and mainly contribute to the central regions of the hosts. Therefore, we suggest that abundance measurements in the inner MW will allow constraining better the parameters of building blocks of the MW stellar halo. The MDFs of the individual debris show several peaks and the majority of debris have lower metallicity than the in-situ stars for Lz>0, while non-rotating and retrograde accreted stars are similar to the in-situ. Prograde accreted stars show a prominent knee in the [Fe/H]-[Mg/Fe] plane while the retrograde stars typically deposit to a high-[Mg/Fe] sequence. We found that the metal-poor stars ([Fe/H]<-1) of the HESTIA galaxies exhibit between zero to 80 km/s net rotation which is consistent with the Aurora population. At higher metallicities, we detect a sharp transition (spin-up) from the turbulent phase to a disk-like rotation. Mergers debris are similar in the [Fe/H]-[Mg/Fe] plane. However, combining a set of abundances allows to capture chemical patterns corresponding to different debris, which are the most prominent as a function of stellar age. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.05491v2-abstract-full').style.display = 'none'; document.getElementById('2206.05491v2-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Paper III in series of III, 21 pages, 17 figures, A&A in press</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 677, A91 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.04522">arXiv:2206.04522</a> <span> [<a href="https://arxiv.org/pdf/2206.04522">pdf</a>, <a href="https://arxiv.org/format/2206.04522">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> </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/10.1051/0004-6361/202244233">10.1051/0004-6361/202244233 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The stellar halo in Local Group Hestia simulations II. The accreted component </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N">Noam Libeskind</a>, <a href="/search/astro-ph?searchtype=author&query=Haywood%2C+M">Misha Haywood</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Matteo%2C+P">Paola Di Matteo</a>, <a href="/search/astro-ph?searchtype=author&query=Belokurov%2C+V">Vasily Belokurov</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+F+A">Facundo A. Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Grand%2C+R+J+J">Robert J. J. Grand</a>, <a href="/search/astro-ph?searchtype=author&query=Hoffman%2C+Y">Yehuda Hoffman</a>, <a href="/search/astro-ph?searchtype=author&query=Knebe%2C+A">Alexander Knebe</a>, <a href="/search/astro-ph?searchtype=author&query=Sorce%2C+J+G">Jenny G. Sorce</a>, <a href="/search/astro-ph?searchtype=author&query=Sparre%2C+M">Martin Sparre</a>, <a href="/search/astro-ph?searchtype=author&query=Tempel%2C+E">Elmo Tempel</a>, <a href="/search/astro-ph?searchtype=author&query=Vogelsberger%2C+M">Mark Vogelsberger</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="2206.04522v2-abstract-short" style="display: inline;"> In the Milky Way, recent progress in the exploration of its assembly history is driven by the tremendous amount of high-quality data delivered by Gaia, which has revealed a number of substructures potentially linked to several ancient accretion events. In this work, aiming to explore the phase-space structure of accreted stars, we analyze six M31/MW analogues from the HESTIA suite of cosmological… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.04522v2-abstract-full').style.display = 'inline'; document.getElementById('2206.04522v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.04522v2-abstract-full" style="display: none;"> In the Milky Way, recent progress in the exploration of its assembly history is driven by the tremendous amount of high-quality data delivered by Gaia, which has revealed a number of substructures potentially linked to several ancient accretion events. In this work, aiming to explore the phase-space structure of accreted stars, we analyze six M31/MW analogues from the HESTIA suite of cosmological hydrodynamics zoom-in simulations of the Local Group. We found that all the HESTIA galaxies experience a few dozen mergers but only 1-4 mergers have the stellar mass ratio >0.2 where, depending on the halo definition, the most massive merger contributes from 20% to 70% of the total stellar halo. Individual merger remnants show diverse density distributions at z=0, significantly overlapping with each other and with the in-situ stars in the ELz, UV and RVphi coordinates. The mergers debris often change their position in the ELz with time due to the galactic mass growth and the non-axisymmetry of the potential. In agreement with previous works, we show that even individual merger debris exhibit a number of distinct ELz features. In the UV plane, all HESTIA galaxies reveal radially hot, non-rotating or weakly counter-rotating, Gaia-Sausage-like features. We found an age gradient in Elz space for the individual debris, where the youngest stars, formed in the inner regions of accreting systems, deposit to the innermost regions of the host. The bulk of these stars is being formed during the last stages of accretion, making it possible to date the merger. In actions space (Jr, Jz, J蠁), the mergers debris do not appear as isolated substructures but are instead scattered over a large parameters area and overlapping with the in-situ stars. We also introduce a purely kinematic space (Jz/Jr-eccentricity), where different merger debris can be disentangled better from each other and from the in-situ stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.04522v2-abstract-full').style.display = 'none'; document.getElementById('2206.04522v2-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Paper II in a series of III, 22 pages, 16 figures, A&A in press</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 677, A90 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.04521">arXiv:2206.04521</a> <span> [<a href="https://arxiv.org/pdf/2206.04521">pdf</a>, <a href="https://arxiv.org/format/2206.04521">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> </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/10.1051/0004-6361/202244232">10.1051/0004-6361/202244232 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The stellar halo in Local Group Hestia simulations I. The in-situ component and the effect of mergers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Khoperskov%2C+S">Sergey Khoperskov</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N">Noam Libeskind</a>, <a href="/search/astro-ph?searchtype=author&query=Haywood%2C+M">Misha Haywood</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Matteo%2C+P">Paola Di Matteo</a>, <a href="/search/astro-ph?searchtype=author&query=Belokurov%2C+V">Vasily Belokurov</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+F+A">Facundo A. Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Grand%2C+R+J+J">Robert J. J. Grand</a>, <a href="/search/astro-ph?searchtype=author&query=Hoffman%2C+Y">Yehuda Hoffman</a>, <a href="/search/astro-ph?searchtype=author&query=Knebe%2C+A">Alexander Knebe</a>, <a href="/search/astro-ph?searchtype=author&query=Sorce%2C+J+G">Jenny G. Sorce</a>, <a href="/search/astro-ph?searchtype=author&query=Sparre%2C+M">Martin Sparre</a>, <a href="/search/astro-ph?searchtype=author&query=Tempel%2C+E">Elmo Tempel</a>, <a href="/search/astro-ph?searchtype=author&query=Vogelsberger%2C+M">Mark Vogelsberger</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="2206.04521v2-abstract-short" style="display: inline;"> Theory suggests that mergers play an important role in shaping galactic discs and stellar haloes, which was observationally confirmed in the MW thanks to Gaia data. In this work, aiming to probe the contribution of mergers to the in situ stellar halo formation, we analyse six M31/MW analogues from the HESTIA suite of cosmological hydrodynamical zoom-in simulations of the LG. We found that all the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.04521v2-abstract-full').style.display = 'inline'; document.getElementById('2206.04521v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.04521v2-abstract-full" style="display: none;"> Theory suggests that mergers play an important role in shaping galactic discs and stellar haloes, which was observationally confirmed in the MW thanks to Gaia data. In this work, aiming to probe the contribution of mergers to the in situ stellar halo formation, we analyse six M31/MW analogues from the HESTIA suite of cosmological hydrodynamical zoom-in simulations of the LG. We found that all the HESTIA galaxies experience between one to four mergers with stellar mass ratios between 0.2 and 1 relative to the host at the time of the merger. These significant mergers, with a single exception, happened 7-11Gyr ago. The overall impact of the most massive mergers in HESTIA is clearly seen as a sharp increase in the orbital eccentricity (and a corresponding decrease in the rotational velocity Vphi of pre-existing disc stars of the main progenitor, thus nicely reproducing the Splash-, Plume-like feature that was discovered in the MW. We do find a correlation between mergers and close pericentric passages of massive satellites and bursts of star formation in the in situ component. Massive mergers sharply increase the disc velocity dispersion of the in situ stars; however, the latest significant merger often heats up the disc up to the numbers when the contribution of the previous ones is less prominent in the age-velocity dispersion relation. In HESTIA galaxies, the in situ halo is an important component of the inner stellar halo where its fraction is about 30-40%, while in the outer parts it typically does not exceed ~5% beyond 15 kpc. The simulations suggest that this component of the stellar haloes continues to grow well after mergers conclude; however, the most significant contribution comes from stars that formed recently before the merger. The orbital analysis of the HESTIA galaxies suggests that wedges in Rmax-Zmax space are mainly populated by the stars born between significant mergers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.04521v2-abstract-full').style.display = 'none'; document.getElementById('2206.04521v2-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Paper I in a series of III, 17 pages, 15 figures, A&A in press</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 677, A89 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.02901">arXiv:2206.02901</a> <span> [<a href="https://arxiv.org/pdf/2206.02901">pdf</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/10.1051/0004-6361/202243141">10.1051/0004-6361/202243141 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Randich%2C+S">S. Randich</a>, <a href="/search/astro-ph?searchtype=author&query=Gilmore%2C+G">G. Gilmore</a>, <a href="/search/astro-ph?searchtype=author&query=Magrini%2C+L">L. Magrini</a>, <a href="/search/astro-ph?searchtype=author&query=Sacco%2C+G+G">G. G. Sacco</a>, <a href="/search/astro-ph?searchtype=author&query=Jackson%2C+R+J">R. J. Jackson</a>, <a href="/search/astro-ph?searchtype=author&query=Jeffries%2C+R+D">R. D. Jeffries</a>, <a href="/search/astro-ph?searchtype=author&query=Worley%2C+C+C">C. C. Worley</a>, <a href="/search/astro-ph?searchtype=author&query=Hourihane%2C+A">A. Hourihane</a>, <a href="/search/astro-ph?searchtype=author&query=Gonneau%2C+A">A. Gonneau</a>, <a href="/search/astro-ph?searchtype=author&query=V%C3%A0zquez%2C+C+V">C. Viscasillas V脿zquez</a>, <a href="/search/astro-ph?searchtype=author&query=Franciosini%2C+E">E. Franciosini</a>, <a href="/search/astro-ph?searchtype=author&query=Lewis%2C+J+R">J. R. Lewis</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+E+J">E. J. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+C+A">C. Allende Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Blomme%2C+T+B+R">T. Bensby R. Blomme</a>, <a href="/search/astro-ph?searchtype=author&query=Bragaglia%2C+A">A. Bragaglia</a>, <a href="/search/astro-ph?searchtype=author&query=Flaccomio%2C+E">E. Flaccomio</a>, <a href="/search/astro-ph?searchtype=author&query=Fran%C3%A7ois%2C+P">P. Fran莽ois</a>, <a href="/search/astro-ph?searchtype=author&query=Irwin%2C+M+J">M. J. Irwin</a>, <a href="/search/astro-ph?searchtype=author&query=Koposov%2C+S+E">S. E. Koposov</a>, <a href="/search/astro-ph?searchtype=author&query=Korn%2C+A+J">A. J. Korn</a>, <a href="/search/astro-ph?searchtype=author&query=Lanzafame%2C+A+C">A. C. Lanzafame</a>, <a href="/search/astro-ph?searchtype=author&query=Pancino%2C+E">E. Pancino</a>, <a href="/search/astro-ph?searchtype=author&query=Recio-Blanco%2C+A">A. Recio-Blanco</a>, <a href="/search/astro-ph?searchtype=author&query=Smiljanic%2C+R">R. Smiljanic</a> , et al. (139 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="2206.02901v1-abstract-short" style="display: inline;"> In the last 15 years different ground-based spectroscopic surveys have been started (and completed) with the general aim of delivering stellar parameters and elemental abundances for large samples of Galactic stars, complementing Gaia astrometry. Among those surveys, the Gaia-ESO Public Spectroscopic Survey (GES), the only one performed on a 8m class telescope, was designed to target 100,000 stars… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.02901v1-abstract-full').style.display = 'inline'; document.getElementById('2206.02901v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.02901v1-abstract-full" style="display: none;"> In the last 15 years different ground-based spectroscopic surveys have been started (and completed) with the general aim of delivering stellar parameters and elemental abundances for large samples of Galactic stars, complementing Gaia astrometry. Among those surveys, the Gaia-ESO Public Spectroscopic Survey (GES), the only one performed on a 8m class telescope, was designed to target 100,000 stars using FLAMES on the ESO VLT (both Giraffe and UVES spectrographs), covering all the Milky Way populations, with a special focus on open star clusters. This article provides an overview of the survey implementation (observations, data quality, analysis and its success, data products, and releases), of the open cluster survey, of the science results and potential, and of the survey legacy. A companion article (Gilmore et al.) reviews the overall survey motivation, strategy, Giraffe pipeline data reduction, organisation, and workflow. The GES has determined homogeneous good-quality radial velocities and stellar parameters for a large fraction of its more than 110,000 unique target stars. Elemental abundances were derived for up to 31 elements for targets observed with UVES. Lithium abundances are delivered for about 1/3 of the sample. The analysis and homogenisation strategies have proven to be successful; several science topics have been addressed by the Gaia-ESO consortium and the community, with many highlight results achieved. The final catalogue has been released through the ESO archive at the end of May 2022, including the complete set of advanced data products. In addition to these results, the Gaia-ESO Survey will leave a very important legacy, for several aspects and for many years to come. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.02901v1-abstract-full').style.display = 'none'; document.getElementById('2206.02901v1-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> 6 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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. 30 pages, 30 figures, 4 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2205.00340">arXiv:2205.00340</a> <span> [<a href="https://arxiv.org/pdf/2205.00340">pdf</a>, <a href="https://arxiv.org/format/2205.00340">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> </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/mnrasl/slac065">10.1093/mnrasl/slac065 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Reliability and limitations of inferring birth radii in the Milky Way disk </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lu%2C+Y">Yuxi Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">Tobias Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Ness%2C+M+K">Melissa K. Ness</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="2205.00340v2-abstract-short" style="display: inline;"> Recovering the birth radii of observed stars in the Milky Way is one of the ultimate goals of Galactic Archaeology. One method to infer the birth radius and the evolution of the ISM metallicity assumes a linear relation between the ISM metallicity with radius at any given look-back time. Here we test the reliability of this assumption by using 4 zoom-in cosmological hydrodynamic simulations from t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.00340v2-abstract-full').style.display = 'inline'; document.getElementById('2205.00340v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.00340v2-abstract-full" style="display: none;"> Recovering the birth radii of observed stars in the Milky Way is one of the ultimate goals of Galactic Archaeology. One method to infer the birth radius and the evolution of the ISM metallicity assumes a linear relation between the ISM metallicity with radius at any given look-back time. Here we test the reliability of this assumption by using 4 zoom-in cosmological hydrodynamic simulations from the NIHAO-UHD project. We find that one can infer precise birth radii only when the stellar disk starts to form, which for our modeled galaxies happens ~ 10 Gyr ago, in agreement with recent estimates for the Milky Way. At later times the linear correlation between the ISM metallicity and radius increases, as stellar motions become more ordered and the azimuthal variations of the ISM metallicity start to drop. The formation of a central bar and perturbations from mergers can increase this uncertainty in the inner and outer disk, respectively. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.00340v2-abstract-full').style.display = 'none'; document.getElementById('2205.00340v2-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 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.01860">arXiv:2111.01860</a> <span> [<a href="https://arxiv.org/pdf/2111.01860">pdf</a>, <a href="https://arxiv.org/format/2111.01860">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/10.1051/0004-6361/202142369">10.1051/0004-6361/202142369 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G=18.5 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">F. Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">A. Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">A. B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Ard%C3%A8vol%2C+J">J. Ard猫vol</a>, <a href="/search/astro-ph?searchtype=author&query=Casamiquela%2C+L">L. Casamiquela</a>, <a href="/search/astro-ph?searchtype=author&query=Figueras%2C+F">F. Figueras</a>, <a href="/search/astro-ph?searchtype=author&query=Jim%C3%A9nez-Arranz%2C+%C3%93">脫. Jim茅nez-Arranz</a>, <a href="/search/astro-ph?searchtype=author&query=Jordi%2C+C">C. Jordi</a>, <a href="/search/astro-ph?searchtype=author&query=Mongui%C3%B3%2C+M">M. Mongui贸</a>, <a href="/search/astro-ph?searchtype=author&query=Romero-G%C3%B3mez%2C+M">M. Romero-G贸mez</a>, <a href="/search/astro-ph?searchtype=author&query=Altamirano%2C+D">D. Altamirano</a>, <a href="/search/astro-ph?searchtype=author&query=Antoja%2C+T">T. Antoja</a>, <a href="/search/astro-ph?searchtype=author&query=Assaad%2C+R">R. Assaad</a>, <a href="/search/astro-ph?searchtype=author&query=Cantat-Gaudin%2C+T">T. Cantat-Gaudin</a>, <a href="/search/astro-ph?searchtype=author&query=Castro-Ginard%2C+A">A. Castro-Ginard</a>, <a href="/search/astro-ph?searchtype=author&query=Enke%2C+H">H. Enke</a>, <a href="/search/astro-ph?searchtype=author&query=Girardi%2C+L">L. Girardi</a>, <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">G. Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=Khan%2C+S">S. Khan</a>, <a href="/search/astro-ph?searchtype=author&query=Luri%2C+X">X. Luri</a>, <a href="/search/astro-ph?searchtype=author&query=Miglio%2C+A">A. Miglio</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Ramos%2C+P">P. Ramos</a>, <a href="/search/astro-ph?searchtype=author&query=Santiago%2C+B+X">B. X. Santiago</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="2111.01860v2-abstract-short" style="display: inline;"> We present a catalogue of 362 million stellar parameters, distances, and extinctions derived from Gaia's early third data release (EDR3) cross-matched with the photometric catalogues of Pan-STARRS1, SkyMapper, 2MASS, and AllWISE. The higher precision of the Gaia EDR3 data, combined with the broad wavelength coverage of the additional photometric surveys and the new stellar-density priors of the {\… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01860v2-abstract-full').style.display = 'inline'; document.getElementById('2111.01860v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.01860v2-abstract-full" style="display: none;"> We present a catalogue of 362 million stellar parameters, distances, and extinctions derived from Gaia's early third data release (EDR3) cross-matched with the photometric catalogues of Pan-STARRS1, SkyMapper, 2MASS, and AllWISE. The higher precision of the Gaia EDR3 data, combined with the broad wavelength coverage of the additional photometric surveys and the new stellar-density priors of the {\tt StarHorse} code allow us to substantially improve the accuracy and precision over previous photo-astrometric stellar-parameter estimates. At magnitude $G=14\, (17)$, our typical precisions amount to 3% (15%) in distance, 0.13 mag (0.15 mag) in $V$-band extinction, and 140 K (180 K) in effective temperature. Our results are validated by comparisons with open clusters, as well as with asteroseismic and spectroscopic measurements, indicating systematic errors smaller than the nominal uncertainties for the vast majority of objects. We also provide distance- and extinction-corrected colour-magnitude diagrams, extinction maps, and extensive stellar density maps that reveal detailed substructures in the Milky Way and beyond. The new density maps now probe a much greater volume, extending to regions beyond the Galactic bar and to Local Group galaxies, with a larger total number density. We publish our results through an ADQL query interface ({\tt gaia.aip.de}) as well as via tables containing approximations of the full posterior distributions. Our multi-wavelength approach and the deep magnitude limit make our results useful also beyond the next Gaia release, DR3. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01860v2-abstract-full').style.display = 'none'; document.getElementById('2111.01860v2-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> 17 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2021. </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">A&A, accepted, 27 pages, 25 figures. Fig. 5 has changed with respect to v1 (post-processing bug corrected). For various options to access the data see https://data.aip.de/projects/starhorse2021.html</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 658, A91 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.01522">arXiv:2111.01522</a> <span> [<a href="https://arxiv.org/pdf/2111.01522">pdf</a>, <a href="https://arxiv.org/format/2111.01522">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> </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/stac3371">10.1093/mnras/stac3371 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> No memory of past warps in the vertical density structure of galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=de+la+Cruz%2C+J+G">J. Garc铆a de la Cruz</a>, <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">M. Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</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="2111.01522v1-abstract-short" style="display: inline;"> Warps are observed in a large fraction of disc galaxies, and can be due to a large number of different processes. Some of these processes might also cause vertical heating and flaring. Using a sample of galaxies simulated in their cosmological context, we study the connection between warping and disc heating. We analyse the vertical stellar density structure within warped stellar discs, and monito… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01522v1-abstract-full').style.display = 'inline'; document.getElementById('2111.01522v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.01522v1-abstract-full" style="display: none;"> Warps are observed in a large fraction of disc galaxies, and can be due to a large number of different processes. Some of these processes might also cause vertical heating and flaring. Using a sample of galaxies simulated in their cosmological context, we study the connection between warping and disc heating. We analyse the vertical stellar density structure within warped stellar discs, and monitor the evolution of the scale-heights of the mono-age populations and the geometrical thin and thick disc during the warp's lifetime. We also compare the overall thickness and the vertical velocity dispersion in the disc before and after the warp. We find that for warps made of pre-existing stellar particles shifted off-plane, the scale-heights do not change within the disc's warped region: discs tilt rigidly. For warps made of off-plane new stellar material (either born in-situ or accreted), the warped region of the disc is not well described by a double $\mathrm{sech^2}$ density profile. Yet, once the warp is gone, the thin and thick disc structure is recovered, with their scale-heights following the same trends as in the region that was never warped. Finally, we find that the overall thickness and vertical velocity dispersion do not increase during a warp, regardless of the warp's origin. This holds even for warps triggered by interactions with satellites, which cause disc heating but before the warp forms. Our findings suggest that the vertical structure of galaxies does not hold any memory of past warps. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01522v1-abstract-full').style.display = 'none'; document.getElementById('2111.01522v1-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 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2021. </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, 7 figures, 1 table. Submitted to 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/2109.09770">arXiv:2109.09770</a> <span> [<a href="https://arxiv.org/pdf/2109.09770">pdf</a>, <a href="https://arxiv.org/format/2109.09770">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> </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/stab2729">10.1093/mnras/stab2729 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> NGC 5746: formation history of a massive disc-dominated galaxy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">Marie Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Pinna%2C+F">Francesca Pinna</a>, <a href="/search/astro-ph?searchtype=author&query=Falc%C3%B3n-Barroso%2C+J">Jes煤s Falc贸n-Barroso</a>, <a href="/search/astro-ph?searchtype=author&query=Gadotti%2C+D">Dimitri Gadotti</a>, <a href="/search/astro-ph?searchtype=author&query=Husemann%2C+B">Bernd Husemann</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Neumann%2C+J">Justus Neumann</a>, <a href="/search/astro-ph?searchtype=author&query=Ruiz-Lara%2C+T">Tom谩s Ruiz-Lara</a>, <a href="/search/astro-ph?searchtype=author&query=van+de+Ven%2C+G">Glenn van de Ven</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="2109.09770v1-abstract-short" style="display: inline;"> The existence of massive galaxies lacking a classical bulge has often been proposed as a challenge to $螞$CDM. However, recent simulations propose that a fraction of massive disc galaxies might have had very quiescent merger histories, and also that mergers do not necessarily build classical bulges. We test these ideas with deep MUSE observations of NGC 5746, a massive ($\sim 10^{11}$ M$_\odot$) ed… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.09770v1-abstract-full').style.display = 'inline'; document.getElementById('2109.09770v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.09770v1-abstract-full" style="display: none;"> The existence of massive galaxies lacking a classical bulge has often been proposed as a challenge to $螞$CDM. However, recent simulations propose that a fraction of massive disc galaxies might have had very quiescent merger histories, and also that mergers do not necessarily build classical bulges. We test these ideas with deep MUSE observations of NGC 5746, a massive ($\sim 10^{11}$ M$_\odot$) edge-on disc galaxy with no classical bulge. We analyse its stellar kinematics and stellar populations, and infer that a massive and extended disc formed very early: 80% of the galaxy's stellar mass formed more than 10 Gyr ago. Most of the thick disc and the bar formed during that early phase. The bar drove gas towards the center and triggered the formation of the nuclear disc followed by the growth of a boxy/peanut-shaped bulge. Around $\sim$ 8 Gyr ago, a $\sim$1:10 merger happened, possibly on a low-inclination orbit. The satellite did not cause significant vertical heating, did not contribute to the growth of a classical bulge, and did not destroy the bar and the nuclear disc. It was however an important event for the galaxy: by depositing its stars throughout the whole galaxy it contributed $\sim 30$% of accreted stars to the thick disc. NGC 5746 thus did not completely escape mergers, but the only relatively recent significant merger did not damage the galaxy and did not create a classical bulge. Future observations will reveal if this is representative of the formation histories of massive disc galaxies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.09770v1-abstract-full').style.display = 'none'; document.getElementById('2109.09770v1-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> 20 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </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. 22 pages, 21 figures (including appendix)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.02741">arXiv:2012.02741</a> <span> [<a href="https://arxiv.org/pdf/2012.02741">pdf</a>, <a href="https://arxiv.org/format/2012.02741">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> </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/staa3906">10.1093/mnras/staa3906 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the Flaring of Thick Disc of Galaxies: Insights from Simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=de+la+Cruz%2C+J+G">Joaqu铆n Garc铆a de la Cruz</a>, <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">Marie Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=James%2C+P">Philip James</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="2012.02741v2-abstract-short" style="display: inline;"> Using simulated galaxies in their cosmological context, we analyse how the flaring of mono-age populations (MAPs) influences the flaring and the age structure of geometrically-defined thick discs. We also explore under which circumstances the geometric thin and thick discs are meaningfully distinct components, or are part of a single continuous structure as in the Milky Way. We find that flat thic… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.02741v2-abstract-full').style.display = 'inline'; document.getElementById('2012.02741v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.02741v2-abstract-full" style="display: none;"> Using simulated galaxies in their cosmological context, we analyse how the flaring of mono-age populations (MAPs) influences the flaring and the age structure of geometrically-defined thick discs. We also explore under which circumstances the geometric thin and thick discs are meaningfully distinct components, or are part of a single continuous structure as in the Milky Way. We find that flat thick discs are created when MAPs barely flare or have low surface density at the radius where they start flaring. When looking at the vertical distribution of MAPs, these galaxies show a continuous thin/thick structure. They also have radial age gradients and tend to have quiescent merger histories. Those characteristics are consistent with what is observed in the Milky Way. Flared thick discs, on the other hand, are created when the MAPs that flare have a high surface density at the radius where they start flaring. The thick discs' scale-heights can either be dominated by multiple MAPs or just a few, depending on the mass and scale-height distribution of the MAPs. In a large fraction of these galaxies, thin and thick discs are clearly distinct structures. Finally, flared thick discs have diverse radial age gradients and merger histories, with galaxies that are more massive or that have undergone massive mergers showing flatter age radial gradients in their thick disc. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.02741v2-abstract-full').style.display = 'none'; document.getElementById('2012.02741v2-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 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </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, 14 figures. Accepted to 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/2010.08268">arXiv:2010.08268</a> <span> [<a href="https://arxiv.org/pdf/2010.08268">pdf</a>, <a href="https://arxiv.org/format/2010.08268">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/10.1051/0004-6361/202039492">10.1051/0004-6361/202039492 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the mass and metallicity distribution of parent AGB stars of presolar SiC </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cristallo%2C+S">Sergio Cristallo</a>, <a href="/search/astro-ph?searchtype=author&query=Nanni%2C+A">Ambra Nanni</a>, <a href="/search/astro-ph?searchtype=author&query=Cescutti%2C+G">Gabriele Cescutti</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+N">Nan Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Vescovi%2C+D">Diego Vescovi</a>, <a href="/search/astro-ph?searchtype=author&query=Gobrecht%2C+D">David Gobrecht</a>, <a href="/search/astro-ph?searchtype=author&query=Piersanti%2C+L">Luciano Piersanti</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="2010.08268v1-abstract-short" style="display: inline;"> The vast majority (>=90%) of presolar SiC grains identified in primitive meteorites are relics of ancient asymptotic giant branch (AGB) stars, whose ejecta were incorporated into the Solar System during its formation. Detailed characterization of these ancient stardust grains has revealed precious information on mixing processes in AGB interiors in great detail. However, the mass and metallicity d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.08268v1-abstract-full').style.display = 'inline'; document.getElementById('2010.08268v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.08268v1-abstract-full" style="display: none;"> The vast majority (>=90%) of presolar SiC grains identified in primitive meteorites are relics of ancient asymptotic giant branch (AGB) stars, whose ejecta were incorporated into the Solar System during its formation. Detailed characterization of these ancient stardust grains has revealed precious information on mixing processes in AGB interiors in great detail. However, the mass and metallicity distribution of their parent stars still remains ambiguous, although such information is crucial to investigating the slow neutron capture process, whose efficiency is mass- and metallicity-dependent. Using a well-known Milky Way chemo-dynamical model, we follow the evolution of the AGB stars that polluted the Solar System at 4.57 Gyr ago and weighted the stars based on their SiC dust productions. We find that presolar SiC in the Solar System predominantly originated from AGB stars with M~2 Msun and Z~Zsun. Our finding well explains the grain-size distribution of presolar SiC identified in situ in primitive meteorites. Moreover, it provides complementary results to very recent papers dealing with the characterization of parent stars of presolar SiC. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.08268v1-abstract-full').style.display = 'none'; document.getElementById('2010.08268v1-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 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </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 on Astronomy & Astrophjysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 644, A8 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2008.04926">arXiv:2008.04926</a> <span> [<a href="https://arxiv.org/pdf/2008.04926">pdf</a>, <a href="https://arxiv.org/format/2008.04926">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> </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/staa2541">10.1093/mnras/staa2541 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Hestia project: simulations of the Local Group </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Libeskind%2C+N+I">Noam I. Libeskind</a>, <a href="/search/astro-ph?searchtype=author&query=Carlesi%2C+E">Edoardo Carlesi</a>, <a href="/search/astro-ph?searchtype=author&query=Grand%2C+R+J+J">Rob J. J. Grand</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">Arman Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Knebe%2C+A">Alexander Knebe</a>, <a href="/search/astro-ph?searchtype=author&query=Pakmor%2C+R">Ruediger Pakmor</a>, <a href="/search/astro-ph?searchtype=author&query=Pilipenko%2C+S">Sergey Pilipenko</a>, <a href="/search/astro-ph?searchtype=author&query=Pawlowski%2C+M+S">Marcel S. Pawlowski</a>, <a href="/search/astro-ph?searchtype=author&query=Sparre%2C+M">Martin Sparre</a>, <a href="/search/astro-ph?searchtype=author&query=Tempel%2C+E">Elmo Tempel</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+P">Peng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Courtois%2C+H+M">Helene M. Courtois</a>, <a href="/search/astro-ph?searchtype=author&query=Gottloeber%2C+S">Stefan Gottloeber</a>, <a href="/search/astro-ph?searchtype=author&query=Hoffman%2C+Y">Yehuda Hoffman</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Pfrommer%2C+C">Christoph Pfrommer</a>, <a href="/search/astro-ph?searchtype=author&query=Sorce%2C+J+G">Jenny G. Sorce</a>, <a href="/search/astro-ph?searchtype=author&query=Springel%2C+V">Volker Springel</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Tully%2C+R+B">R. Brent Tully</a>, <a href="/search/astro-ph?searchtype=author&query=Vogelsberger%2C+M">Mark Vogelsberger</a>, <a href="/search/astro-ph?searchtype=author&query=Yepes%2C+G">Gustavo Yepes</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="2008.04926v1-abstract-short" style="display: inline;"> We present the Hestia simulation suite: High-resolutions Environmental Simulations of The Immediate Area, a set of cosmological simulations of the Local Group. Initial conditions constrained by the observed peculiar velocity of nearby galaxies are employed to accurately simulate the local cosmography. Halo pairs that resemble the Local Group are found in low resolutions constrained, dark matter on… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.04926v1-abstract-full').style.display = 'inline'; document.getElementById('2008.04926v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.04926v1-abstract-full" style="display: none;"> We present the Hestia simulation suite: High-resolutions Environmental Simulations of The Immediate Area, a set of cosmological simulations of the Local Group. Initial conditions constrained by the observed peculiar velocity of nearby galaxies are employed to accurately simulate the local cosmography. Halo pairs that resemble the Local Group are found in low resolutions constrained, dark matter only simulations, and selected for higher resolution magneto hydrodynamic simulation using the Arepo code. Baryonic physics follows the Auriga model of galaxy formation. The simulations contain a high resolution region of 3-5 Mpc in radius from the Local Group midpoint embedded in the correct cosmographic landscape. Within this region a simulated Local Group consisting of a Milky Way and Andromeda like galaxy forms, whose description is in excellent agreement with observations. The simulated Local Group galaxies resemble the Milky Way and Andromeda in terms of their halo mass, mass ratio, stellar disc mass, morphology separation, relative velocity, rotation curves, bulge-disc morphology, satellite galaxy stellar mass function, satellite radial distribution and in some cases, the presence of a Magellanic cloud like object. Because these simulations properly model the Local Group in their cosmographic context, they provide a testing ground for questions where environment is thought to play an important role. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.04926v1-abstract-full').style.display = 'none'; document.getElementById('2008.04926v1-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 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </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, 13 figures, submitted to 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/2007.13749">arXiv:2007.13749</a> <span> [<a href="https://arxiv.org/pdf/2007.13749">pdf</a>, <a href="https://arxiv.org/format/2007.13749">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> </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/10.1051/0004-6361/202038651">10.1051/0004-6361/202038651 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Is NGC 300 a pure exponential disk galaxy? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jang%2C+I+S">In Sung Jang</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">Roelof S. de Jong</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Bell%2C+E+F">Eric F. Bell</a>, <a href="/search/astro-ph?searchtype=author&query=Monachesi%2C+A">Antonela Monachesi</a>, <a href="/search/astro-ph?searchtype=author&query=Holwerda%2C+B+W">Benne W. Holwerda</a>, <a href="/search/astro-ph?searchtype=author&query=Bailin%2C+J">Jeremy Bailin</a>, <a href="/search/astro-ph?searchtype=author&query=Smercina%2C+A">Adam Smercina</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Souza%2C+R">Richard D'Souza</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="2007.13749v1-abstract-short" style="display: inline;"> NGC 300 is a low-mass disk galaxy in the Sculptor group. In the literature, it has been identified as a pure exponential disk galaxy, as its luminosity profile could be well fitted with a single exponential law over many disk scale lengths (Type I). We investigate the stellar luminosity distribution of NGC 300 using $Hubble$ $Space$ $Telescope$ (HST) archive data, reaching farther and deeper than… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.13749v1-abstract-full').style.display = 'inline'; document.getElementById('2007.13749v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.13749v1-abstract-full" style="display: none;"> NGC 300 is a low-mass disk galaxy in the Sculptor group. In the literature, it has been identified as a pure exponential disk galaxy, as its luminosity profile could be well fitted with a single exponential law over many disk scale lengths (Type I). We investigate the stellar luminosity distribution of NGC 300 using $Hubble$ $Space$ $Telescope$ (HST) archive data, reaching farther and deeper than any other previous studies. Color magnitude diagrams show a significant population of old red giant branch (RGB) stars in all fields out to $R\sim19$ kpc ($32'$), as well as younger populations in the inner regions. We construct the density profiles of the young, intermediate-aged, and old stellar populations. We find two clear breaks in the density profiles of the old RGB and intermediate-aged stars: one down-bending (Type II) at $R\sim5.9$ kpc, and another up-bending (Type III) at $R\sim8.3$ kpc. Moreover, the old RGB stars exhibit a negative radial color gradient with an up-bending at $R\sim8$~kpc, beyond which the stellar populations are uniformly old ($>$7~Gyr) and metal-poor ($\rm[Fe/H] = -1.6^{+0.2}_{-0.4}$ dex). The outer stellar component at $R\gtrapprox8$ kpc is, therefore, well separated from the inner disk in terms of the stellar density and stellar populations. While our results cast doubt on the currently established wisdom that NGC\,300 is a pure exponential disk galaxy, a more detailed survey should be carried out to identify the outskirts as either a disk or a stellar halo. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.13749v1-abstract-full').style.display = 'none'; document.getElementById('2007.13749v1-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 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </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, 5 figures, 1 appendix, accepted for publication in A&A Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.12915">arXiv:2007.12915</a> <span> [<a href="https://arxiv.org/pdf/2007.12915">pdf</a>, <a href="https://arxiv.org/format/2007.12915">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> </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/10.1051/0004-6361/202039030">10.1051/0004-6361/202039030 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Milky Way bar and bulge revealed by APOGEE DR16 and Gaia EDR3 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">A. B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Perez-Villegas%2C+A">A. Perez-Villegas</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">A. Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">F. Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Barbuy%2C+B">B. Barbuy</a>, <a href="/search/astro-ph?searchtype=author&query=Santiago%2C+B+X">B. X. Santiago</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Cunha%2C+K">K. Cunha</a>, <a href="/search/astro-ph?searchtype=author&query=Schultheis%2C+M">M. Schultheis</a>, <a href="/search/astro-ph?searchtype=author&query=Majewski%2C+S+R">S. R. Majewski</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Minniti%2C+D">D. Minniti</a>, <a href="/search/astro-ph?searchtype=author&query=Beaton%2C+R+L">R. L. Beaton</a>, <a href="/search/astro-ph?searchtype=author&query=Cohen%2C+R+E">R. E. Cohen</a>, <a href="/search/astro-ph?searchtype=author&query=da+Costa%2C+L+N">L. N. da Costa</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez-Trincado%2C+J+G">J. G. Fern谩ndez-Trincado</a>, <a href="/search/astro-ph?searchtype=author&query=Garcia-Hern%C3%A1ndez%2C+D+A">D. A. Garcia-Hern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Geisler%2C+D">D. Geisler</a>, <a href="/search/astro-ph?searchtype=author&query=Hasselquist%2C+S">S. Hasselquist</a>, <a href="/search/astro-ph?searchtype=author&query=Lane%2C+R+R">R. R. Lane</a>, <a href="/search/astro-ph?searchtype=author&query=Nitschelm%2C+C">C. Nitschelm</a>, <a href="/search/astro-ph?searchtype=author&query=Rojas-Arriagada%2C+A">A. Rojas-Arriagada</a>, <a href="/search/astro-ph?searchtype=author&query=Roman-Lopes%2C+A">A. Roman-Lopes</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+V">V. Smith</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="2007.12915v4-abstract-short" style="display: inline;"> We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and Gaia EDR3 data. Our inner Galactic sample has more than 26,000 stars within $|X_{\rm Gal}| <5$ kpc, $|Y_{\rm Gal}| <3.5$ kpc, $|Z_{\rm Gal}| <1$ kpc, and we also make the analysis for a foreground-cleaned sub-sample of 8,000 stars more representative of the bulge-bar populat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.12915v4-abstract-full').style.display = 'inline'; document.getElementById('2007.12915v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.12915v4-abstract-full" style="display: none;"> We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and Gaia EDR3 data. Our inner Galactic sample has more than 26,000 stars within $|X_{\rm Gal}| <5$ kpc, $|Y_{\rm Gal}| <3.5$ kpc, $|Z_{\rm Gal}| <1$ kpc, and we also make the analysis for a foreground-cleaned sub-sample of 8,000 stars more representative of the bulge-bar populations. The inner Galaxy shows a clear chemical discontinuity in key abundance ratios [$伪$/Fe], [C/N], and [Mn/O], probing different enrichment timescales, which suggests a star formation gap (quenching) between the high- and low-$伪$ populations. For the first time, we are able to fully characterize the different populations co-existing in the innermost regions of the Galaxy via joint analysis of the distributions of rotational velocities, metallicities, orbital parameters and chemical abundances. The chemo-kinematic analysis reveals the presence of the bar; of an inner thin disk; of a thick disk, and of a broad metallicity population, with a large velocity dispersion, indicative of a pressure supported component. We find and characterize chemically and kinematically a group of counter-rotating stars, which could be the result of a gas-rich merger event or just the result of clumpy star formation during the earliest phases of the early disk, which migrated into the bulge. Finally, based on the 6D information we assign stars a probability value of being on a bar orbit and find that most of the stars with large bar orbit probabilities come from the innermost 3 kpcs. Even stars with a high probability of belonging to the bar show the chemical bimodality in the [$伪$/Fe] vs. [Fe/H] diagram. This suggests bar trapping to be an efficient mechanism, explaining why stars on bar orbits do not show a significant distinct chemical abundance ratio signature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.12915v4-abstract-full').style.display = 'none'; document.getElementById('2007.12915v4-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 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </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, 25 figures, Accepted for publication on A&A, in press</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 656, A156 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.03307">arXiv:2007.03307</a> <span> [<a href="https://arxiv.org/pdf/2007.03307">pdf</a>, <a href="https://arxiv.org/format/2007.03307">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</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> </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/staa2285">10.1093/mnras/staa2285 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An optimised tiling pattern for multi-object spectroscopic surveys: application to the 4MOST survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Tempel%2C+E">E. Tempel</a>, <a href="/search/astro-ph?searchtype=author&query=Tuvikene%2C+T">T. Tuvikene</a>, <a href="/search/astro-ph?searchtype=author&query=Muru%2C+M+M">M. M. Muru</a>, <a href="/search/astro-ph?searchtype=author&query=Stoica%2C+R+S">R. S. Stoica</a>, <a href="/search/astro-ph?searchtype=author&query=Bensby%2C+T">T. Bensby</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Christlieb%2C+N">N. Christlieb</a>, <a href="/search/astro-ph?searchtype=author&query=Cioni%2C+M+-+L">M. -R. L. Cioni</a>, <a href="/search/astro-ph?searchtype=author&query=Comparat%2C+J">J. Comparat</a>, <a href="/search/astro-ph?searchtype=author&query=Feltzing%2C+S">S. Feltzing</a>, <a href="/search/astro-ph?searchtype=author&query=Hook%2C+I">I. Hook</a>, <a href="/search/astro-ph?searchtype=author&query=Koch%2C+A">A. Koch</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">G. Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Krumpe%2C+M">M. Krumpe</a>, <a href="/search/astro-ph?searchtype=author&query=Loveday%2C+J">J. Loveday</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Norberg%2C+P">P. Norberg</a>, <a href="/search/astro-ph?searchtype=author&query=Roukema%2C+B+F">B. F. Roukema</a>, <a href="/search/astro-ph?searchtype=author&query=Sorce%2C+J+G">J. G. Sorce</a>, <a href="/search/astro-ph?searchtype=author&query=Storm%2C+J">J. Storm</a>, <a href="/search/astro-ph?searchtype=author&query=Swann%2C+E">E. Swann</a>, <a href="/search/astro-ph?searchtype=author&query=Taylor%2C+E+N">E. N. Taylor</a>, <a href="/search/astro-ph?searchtype=author&query=Traven%2C+G">G. Traven</a>, <a href="/search/astro-ph?searchtype=author&query=Walcher%2C+C+J">C. J. Walcher</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">R. S. de Jong</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="2007.03307v1-abstract-short" style="display: inline;"> Large multi-object spectroscopic surveys require automated algorithms to optimise their observing strategy. One of the most ambitious upcoming spectroscopic surveys is the 4MOST survey. The 4MOST survey facility is a fibre-fed spectroscopic instrument on the VISTA telescope with a large enough field of view to survey a large fraction of the southern sky within a few years. Several Galactic and ext… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.03307v1-abstract-full').style.display = 'inline'; document.getElementById('2007.03307v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.03307v1-abstract-full" style="display: none;"> Large multi-object spectroscopic surveys require automated algorithms to optimise their observing strategy. One of the most ambitious upcoming spectroscopic surveys is the 4MOST survey. The 4MOST survey facility is a fibre-fed spectroscopic instrument on the VISTA telescope with a large enough field of view to survey a large fraction of the southern sky within a few years. Several Galactic and extragalactic surveys will be carried out simultaneously, so the combined target density will strongly vary. In this paper, we describe a new tiling algorithm that can naturally deal with the large target density variations on the sky and which automatically handles the different exposure times of targets. The tiling pattern is modelled as a marked point process, which is characterised by a probability density that integrates the requirements imposed by the 4MOST survey. The optimal tilling pattern with respect to the defined model is estimated by the tiles configuration that maximises the proposed probability density. In order to achieve this maximisation a simulated annealing algorithm is implemented. The algorithm automatically finds an optimal tiling pattern and assigns a tentative sky brightness condition and exposure time for each tile, while minimising the total execution time that is needed to observe the list of targets in the combined input catalogue of all surveys. Hence, the algorithm maximises the long-term observing efficiency and provides an optimal tiling solution for the survey. While designed for the 4MOST survey, the algorithm is flexible and can with simple modifications be applied to any other multi-object spectroscopic survey. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.03307v1-abstract-full').style.display = 'none'; document.getElementById('2007.03307v1-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 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </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, 11 figures, submitted to 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/2006.01723">arXiv:2006.01723</a> <span> [<a href="https://arxiv.org/pdf/2006.01723">pdf</a>, <a href="https://arxiv.org/format/2006.01723">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> </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/staa3189">10.1093/mnras/staa3189 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Birth Sites of Young Stellar Associations and Recent Star Formation in a Flocculent Corrugated Disk </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Quillen%2C+A+C">Alice C. Quillen</a>, <a href="/search/astro-ph?searchtype=author&query=Pettitt%2C+A+R">Alex R. Pettitt</a>, <a href="/search/astro-ph?searchtype=author&query=Chakrabarti%2C+S">Sukanya Chakrabarti</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y">Yifan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Gagn%C3%A9%2C+J">Jonathan Gagn茅</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</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="2006.01723v3-abstract-short" style="display: inline;"> With backwards orbit integration we estimate birth locations of young stellar associations and moving groups identified in the solar neighborhood that are younger than 70 Myr. The birth locations of most of these stellar associations are at smaller galactocentric radius than the Sun, implying that their stars moved radially outwards after birth. Exceptions to this rule include are the Argus and Oc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.01723v3-abstract-full').style.display = 'inline'; document.getElementById('2006.01723v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.01723v3-abstract-full" style="display: none;"> With backwards orbit integration we estimate birth locations of young stellar associations and moving groups identified in the solar neighborhood that are younger than 70 Myr. The birth locations of most of these stellar associations are at smaller galactocentric radius than the Sun, implying that their stars moved radially outwards after birth. Exceptions to this rule include are the Argus and Octans associations which formed outside the Sun's Galactocentric radius. Variations in birth heights of the stellar associations suggest that they were born in a corrugated disk of molecular clouds, similar to that inferred from the current filamentary molecular cloud distribution and dust extinction maps. Multiple spiral arm features with different but near corotation pattern speeds and at different heights could account for the stellar association birth sites. We find that the young stellar associations are located in between peaks in the UV stellar velocity distribution for stars in the solar neighborhood. This would be expected if they were born in a spiral arm which perturbs stellar orbits that cross it. In contrast, stellar associations seem to be located near peaks in the vertical phase space distribution, suggesting that the gas in which stellar associations are born moves vertically together with the low velocity dispersion disk stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.01723v3-abstract-full').style.display = 'none'; document.getElementById('2006.01723v3-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 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </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">The animated movie is available here: http://astro.pas.rochester.edu/~aquillen/figures/movie3D.gif</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.12666">arXiv:2004.12666</a> <span> [<a href="https://arxiv.org/pdf/2004.12666">pdf</a>, <a href="https://arxiv.org/format/2004.12666">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</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/10.1051/0004-6361/202038271">10.1051/0004-6361/202038271 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The RAdial Velocity Experiment (RAVE): Parameterisation of RAVE spectra based on convolutional neural networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">G. Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=Matijevic%2C+G">G. Matijevic</a>, <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">A. B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">M. Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Grebel%2C+E+K">E. K. Grebel</a>, <a href="/search/astro-ph?searchtype=author&query=McMillan%2C+P+J">P. J. McMillan</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">G. Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Kunder%2C+A">A. Kunder</a>, <a href="/search/astro-ph?searchtype=author&query=Zwitter%2C+T">T. Zwitter</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">A. Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">F. Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Enke%2C+H">H. Enke</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Monari%2C+G">G. Monari</a>, <a href="/search/astro-ph?searchtype=author&query=Wyse%2C+R+F+G">R. F. G. Wyse</a>, <a href="/search/astro-ph?searchtype=author&query=Bienayme%2C+O">O. Bienayme</a>, <a href="/search/astro-ph?searchtype=author&query=Bland-Hawthorn%2C+J">J. Bland-Hawthorn</a>, <a href="/search/astro-ph?searchtype=author&query=Gibson%2C+B+K">B. K. Gibson</a>, <a href="/search/astro-ph?searchtype=author&query=Navarro%2C+J+F">J. F. Navarro</a>, <a href="/search/astro-ph?searchtype=author&query=Parker%2C+Q">Q. Parker</a>, <a href="/search/astro-ph?searchtype=author&query=Reid%2C+W">W. Reid</a>, <a href="/search/astro-ph?searchtype=author&query=Seabroke%2C+G+M">G. M. Seabroke</a>, <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+A">A. Siebert</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="2004.12666v3-abstract-short" style="display: inline;"> In the context of large spectroscopic surveys of stars, data-driven methods are key in deducing physical parameters for millions of spectra in a short time. Convolutional neural networks (CNNs) enable us to connect observables (e.g. spectra, stellar magnitudes) to physical properties (atmospheric parameters, chemical abundances, or labels in general). We trained a CNN, adopting stellar atmospheric… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.12666v3-abstract-full').style.display = 'inline'; document.getElementById('2004.12666v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.12666v3-abstract-full" style="display: none;"> In the context of large spectroscopic surveys of stars, data-driven methods are key in deducing physical parameters for millions of spectra in a short time. Convolutional neural networks (CNNs) enable us to connect observables (e.g. spectra, stellar magnitudes) to physical properties (atmospheric parameters, chemical abundances, or labels in general). We trained a CNN, adopting stellar atmospheric parameters and chemical abundances from APOGEE DR16 (resolution R=22500) data as training set labels. As input, we used parts of the intermediate-resolution RAVE DR6 spectra (R~7500) overlapping with the APOGEE DR16 data as well as broad-band ALL_WISE and 2MASS photometry, together with Gaia DR2 photometry and parallaxes. We derived precise atmospheric parameters Teff, log(g), and [M/H] along with the chemical abundances of [Fe/H], [alpha/M], [Mg/Fe], [Si/Fe], [Al/Fe], and [Ni/Fe] for 420165 RAVE spectra. The precision typically amounts to 60K in Teff, 0.06 in log(g) and 0.02-0.04 dex for individual chemical abundances. Incorporating photometry and astrometry as additional constraints substantially improves the results in terms of the accuracy and precision of the derived labels. We provide a catalogue of CNN-trained atmospheric parameters and abundances along with their uncertainties for 420165 stars in the RAVE survey. CNN-based methods provide a powerful way to combine spectroscopic, photometric, and astrometric data without the need to apply any priors in the form of stellar evolutionary models. The developed procedure can extend the scientific output of RAVE spectra beyond DR6 to ongoing and planned surveys such as Gaia RVS, 4MOST, and WEAVE. We call on the community to place a particular collective emphasis and on efforts to create unbiased training samples for such future spectroscopic surveys. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.12666v3-abstract-full').style.display = 'none'; document.getElementById('2004.12666v3-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 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </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">31 pages, 30 figures, accepted for publication in A&A, in Press</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 644, A168 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.05457">arXiv:2003.05457</a> <span> [<a href="https://arxiv.org/pdf/2003.05457">pdf</a>, <a href="https://arxiv.org/format/2003.05457">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> </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/staa1934">10.1093/mnras/staa1934 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fluctuations in galactic bar parameters due to bar-spiral interaction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hilmi%2C+T">T. Hilmi</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Buck%2C+T">T. Buck</a>, <a href="/search/astro-ph?searchtype=author&query=Martig%2C+M">M. Martig</a>, <a href="/search/astro-ph?searchtype=author&query=Quillen%2C+A+C">A. C. Quillen</a>, <a href="/search/astro-ph?searchtype=author&query=Monari%2C+G">G. Monari</a>, <a href="/search/astro-ph?searchtype=author&query=Famaey%2C+B">B. Famaey</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">R. S. de Jong</a>, <a href="/search/astro-ph?searchtype=author&query=Laporte%2C+C+F+P">C. F. P. Laporte</a>, <a href="/search/astro-ph?searchtype=author&query=Read%2C+J">J. Read</a>, <a href="/search/astro-ph?searchtype=author&query=Sanders%2C+J+L">J. L. Sanders</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Wegg%2C+C">C. Wegg</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="2003.05457v3-abstract-short" style="display: inline;"> We study the late-time evolution of the central regions of two Milky Way-like simulations of galaxies formed in a cosmological context, one hosting a fast bar and the other a slow one. We find that bar length, R_b, measurements fluctuate on a dynamical timescale by up to 100%, depending on the spiral structure strength and measurement threshold. The bar amplitude oscillates by about 15%, correlati… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.05457v3-abstract-full').style.display = 'inline'; document.getElementById('2003.05457v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.05457v3-abstract-full" style="display: none;"> We study the late-time evolution of the central regions of two Milky Way-like simulations of galaxies formed in a cosmological context, one hosting a fast bar and the other a slow one. We find that bar length, R_b, measurements fluctuate on a dynamical timescale by up to 100%, depending on the spiral structure strength and measurement threshold. The bar amplitude oscillates by about 15%, correlating with R_b. The Tremaine-Weinberg-method estimates of the bars' instantaneous pattern speeds show variations around the mean of up to ~20%, typically anti-correlating with the bar length and strength. Through power spectrum analyses, we establish that these bar pulsations, with a period in the range ~60-200 Myr, result from its interaction with multiple spiral modes, which are coupled with the bar. Because of the presence of odd spiral modes, the two bar halves typically do not connect at exactly the same time to a spiral arm, and their individual lengths can be significantly offset. We estimated that in about 50% of bar measurements in Milky Way-mass external galaxies, the bar lengths of SBab type galaxies are overestimated by ~15% and those of SBbc types by ~55%. Consequently, bars longer than their corotation radius reported in the literature, dubbed "ultra-fast bars", may simply correspond to the largest biases. Given that the Scutum-Centaurus arm is likely connected to the near half of the Milky Way bar, recent direct measurements may be overestimating its length by 1-1.5 kpc, while its present pattern speed may be 5-10 km/s/kpc smaller than its time-averaged value. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.05457v3-abstract-full').style.display = 'none'; document.getElementById('2003.05457v3-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 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </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 p., 19 figures, Accepted to 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/2002.04512">arXiv:2002.04512</a> <span> [<a href="https://arxiv.org/pdf/2002.04512">pdf</a>, <a href="https://arxiv.org/format/2002.04512">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/ab9ab8">10.3847/1538-3881/ab9ab8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Sixth Data Release of the Radial Velocity Experiment (RAVE) -- II: Stellar Atmospheric Parameters, Chemical Abundances and Distances </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">Guillaume Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=McMillan%2C+P+J">Paul J. McMillan</a>, <a href="/search/astro-ph?searchtype=author&query=Matijevic%2C+G">Gal Matijevic</a>, <a href="/search/astro-ph?searchtype=author&query=Enke%2C+H">Harry Enke</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">Georges Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Zwitter%2C+T">Tomaz Zwitter</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">Marica Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">Cristina Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Casagrande%2C+L">Luca Casagrande</a>, <a href="/search/astro-ph?searchtype=author&query=Wojno%2C+J">Jennifer Wojno</a>, <a href="/search/astro-ph?searchtype=author&query=Anguiano%2C+B">Borja Anguiano</a>, <a href="/search/astro-ph?searchtype=author&query=Bienayme%2C+O">Olivier Bienayme</a>, <a href="/search/astro-ph?searchtype=author&query=Bijaoui%2C+A">Albert Bijaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Binney%2C+J">James Binney</a>, <a href="/search/astro-ph?searchtype=author&query=Burton%2C+D">Donna Burton</a>, <a href="/search/astro-ph?searchtype=author&query=Cass%2C+P">Paul Cass</a>, <a href="/search/astro-ph?searchtype=author&query=de+Laverny%2C+P">Patrick de Laverny</a>, <a href="/search/astro-ph?searchtype=author&query=Fiegert%2C+K">Kristin Fiegert</a>, <a href="/search/astro-ph?searchtype=author&query=Freeman%2C+K">Kenneth Freeman</a>, <a href="/search/astro-ph?searchtype=author&query=Fulbright%2C+J+P">Jon P. Fulbright</a>, <a href="/search/astro-ph?searchtype=author&query=Gibson%2C+B+K">Brad K. Gibson</a>, <a href="/search/astro-ph?searchtype=author&query=Gilmore%2C+G">Gerard Gilmore</a>, <a href="/search/astro-ph?searchtype=author&query=Grebel%2C+E+K">Eva K. Grebel</a>, <a href="/search/astro-ph?searchtype=author&query=Helmi%2C+A">Amina Helmi</a> , et al. (36 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="2002.04512v2-abstract-short" style="display: inline;"> We present part 2 of the 6th and final Data Release (DR6 or FDR) of the Radial Velocity Experiment (RAVE), a magnitude-limited (9<I<12) spectroscopic survey of Galactic stars randomly selected in the southern hemisphere. The RAVE medium-resolution spectra (R~7500) cover the Ca-triplet region (8410-8795A) and span the complete time frame from the start of RAVE observations on 12 April 2003 to their… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.04512v2-abstract-full').style.display = 'inline'; document.getElementById('2002.04512v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.04512v2-abstract-full" style="display: none;"> We present part 2 of the 6th and final Data Release (DR6 or FDR) of the Radial Velocity Experiment (RAVE), a magnitude-limited (9<I<12) spectroscopic survey of Galactic stars randomly selected in the southern hemisphere. The RAVE medium-resolution spectra (R~7500) cover the Ca-triplet region (8410-8795A) and span the complete time frame from the start of RAVE observations on 12 April 2003 to their completion on 4 April 2013. In the second of two publications, we present the data products derived from 518387 observations of 451783 unique stars using a suite of advanced reduction pipelines focussing on stellar atmospheric parameters, in particular purely spectroscopically derived stellar atmospheric parameters (Teff, log(g), and the overall metallicity), enhanced stellar atmospheric parameters inferred via a Bayesian pipeline using Gaia DR2 astrometric priors, and asteroseismically calibrated stellar atmospheric parameters for giant stars based on asteroseismic observations for 699 K2 stars. In addition, we provide abundances of the elements Fe, Al, and Ni, as well as an overall [alpha/Fe] ratio obtained using a new pipeline based on the GAUGUIN optimization method that is able to deal with variable signal-to-noise ratios. The RAVE DR6 catalogs are cross matched with relevant astrometric and photometric catalogs, and are complemented by orbital parameters and effective temperatures based on the infrared flux method. The data can be accessed via the RAVE Web site (http://rave-survey.org) or the Vizier database. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.04512v2-abstract-full').style.display = 'none'; document.getElementById('2002.04512v2-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 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </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">65 pages, 33 figures, accepted for publication to 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/2002.04377">arXiv:2002.04377</a> <span> [<a href="https://arxiv.org/pdf/2002.04377">pdf</a>, <a href="https://arxiv.org/format/2002.04377">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/10.3847/1538-3881/ab9ab9">10.3847/1538-3881/ab9ab9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Sixth Data Release of the Radial Velocity Experiment (RAVE) -- I: Survey Description, Spectra and Radial Velocities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">Matthias Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Matijevic%2C+G">Gal Matijevic</a>, <a href="/search/astro-ph?searchtype=author&query=Enke%2C+H">Harry Enke</a>, <a href="/search/astro-ph?searchtype=author&query=Zwitter%2C+T">Tomaz Zwitter</a>, <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">Guillaume Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=McMillan%2C+P+J">Paul J. McMillan</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">Georges Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">Marica Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">Cristina Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Casagrande%2C+L">Luca Casagrande</a>, <a href="/search/astro-ph?searchtype=author&query=Wojno%2C+J">Jennifer Wojno</a>, <a href="/search/astro-ph?searchtype=author&query=Anguiano%2C+B">Borja Anguiano</a>, <a href="/search/astro-ph?searchtype=author&query=Bienayme%2C+O">Olivier Bienayme</a>, <a href="/search/astro-ph?searchtype=author&query=Bijaoui%2C+A">Albert Bijaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Binney%2C+J">James Binney</a>, <a href="/search/astro-ph?searchtype=author&query=Burton%2C+D">Donna Burton</a>, <a href="/search/astro-ph?searchtype=author&query=Cass%2C+P">Paul Cass</a>, <a href="/search/astro-ph?searchtype=author&query=de+Laverny%2C+P">Patrick de Laverny</a>, <a href="/search/astro-ph?searchtype=author&query=Fiegert%2C+K">Kristin Fiegert</a>, <a href="/search/astro-ph?searchtype=author&query=Freeman%2C+K">Kenneth Freeman</a>, <a href="/search/astro-ph?searchtype=author&query=Fulbright%2C+J+P">Jon P. Fulbright</a>, <a href="/search/astro-ph?searchtype=author&query=Gibson%2C+B+K">Brad K. Gibson</a>, <a href="/search/astro-ph?searchtype=author&query=Gilmore%2C+G">Gerard Gilmore</a>, <a href="/search/astro-ph?searchtype=author&query=Grebel%2C+E+K">Eva K. Grebel</a>, <a href="/search/astro-ph?searchtype=author&query=Helmi%2C+A">Amina Helmi</a> , et al. (37 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="2002.04377v2-abstract-short" style="display: inline;"> The Radial Velocity Experiment (RAVE) is a magnitude-limited (9<I<12) spectroscopic survey of Galactic stars randomly selected in the southern hemisphere. The RAVE medium-resolution spectra (R~7500) cover the Ca-triplet region (8410-8795A). The 6th and final data release (DR6 or FDR) is based on 518387 observations of 451783 unique stars. RAVE observations were taken between 12 April 2003 and 4 Ap… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.04377v2-abstract-full').style.display = 'inline'; document.getElementById('2002.04377v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.04377v2-abstract-full" style="display: none;"> The Radial Velocity Experiment (RAVE) is a magnitude-limited (9<I<12) spectroscopic survey of Galactic stars randomly selected in the southern hemisphere. The RAVE medium-resolution spectra (R~7500) cover the Ca-triplet region (8410-8795A). The 6th and final data release (DR6 or FDR) is based on 518387 observations of 451783 unique stars. RAVE observations were taken between 12 April 2003 and 4 April 2013. Here we present the genesis, setup and data reduction of RAVE as well as wavelength-calibrated and flux-normalized spectra and error spectra for all observations in RAVE DR6. Furthermore, we present derived spectral classification and radial velocities for the RAVE targets, complemented by cross matches with Gaia DR2 and other relevant catalogs. A comparison between internal error estimates, variances derived from stars with more than one observing epoch and a comparison with radial velocities of Gaia DR2 reveals consistently that 68% of the objects have a velocity accuracy better than 1.4 km/s, while 95% of the objects have radial velocities better than 4.0 km/s. Stellar atmospheric parameters, abundances and distances are presented in subsequent publication. The data can be accessed via the RAVE Web (http://rave-survey.org) or the Vizier database. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.04377v2-abstract-full').style.display = 'none'; document.getElementById('2002.04377v2-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 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </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">32 pages, 11 figures, accepted for publication to 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/2001.09348">arXiv:2001.09348</a> <span> [<a href="https://arxiv.org/pdf/2001.09348">pdf</a>, <a href="https://arxiv.org/format/2001.09348">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</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/10.1051/0004-6361/201937228">10.1051/0004-6361/201937228 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Probabilistic fibre-to-target assignment algorithm for multi-object spectroscopic surveys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Tempel%2C+E">E. Tempel</a>, <a href="/search/astro-ph?searchtype=author&query=Norberg%2C+P">P. Norberg</a>, <a href="/search/astro-ph?searchtype=author&query=Tuvikene%2C+T">T. Tuvikene</a>, <a href="/search/astro-ph?searchtype=author&query=Bensby%2C+T">T. Bensby</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Christlieb%2C+N">N. Christlieb</a>, <a href="/search/astro-ph?searchtype=author&query=Cioni%2C+M+-+L">M. -R. L. Cioni</a>, <a href="/search/astro-ph?searchtype=author&query=Comparat%2C+J">J. Comparat</a>, <a href="/search/astro-ph?searchtype=author&query=Davies%2C+L+J+M">L. J. M. Davies</a>, <a href="/search/astro-ph?searchtype=author&query=Guiglion%2C+G">G. Guiglion</a>, <a href="/search/astro-ph?searchtype=author&query=Koch%2C+A">A. Koch</a>, <a href="/search/astro-ph?searchtype=author&query=Kordopatis%2C+G">G. Kordopatis</a>, <a href="/search/astro-ph?searchtype=author&query=Krumpe%2C+M">M. Krumpe</a>, <a href="/search/astro-ph?searchtype=author&query=Loveday%2C+J">J. Loveday</a>, <a href="/search/astro-ph?searchtype=author&query=Merloni%2C+A">A. Merloni</a>, <a href="/search/astro-ph?searchtype=author&query=Micheva%2C+G">G. Micheva</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Roukema%2C+B+F">B. F. Roukema</a>, <a href="/search/astro-ph?searchtype=author&query=Sorce%2C+J+G">J. G. Sorce</a>, <a href="/search/astro-ph?searchtype=author&query=Starkenburg%2C+E">E. Starkenburg</a>, <a href="/search/astro-ph?searchtype=author&query=Storm%2C+J">J. Storm</a>, <a href="/search/astro-ph?searchtype=author&query=Swann%2C+E">E. Swann</a>, <a href="/search/astro-ph?searchtype=author&query=Thi%2C+W+F">W. F. Thi</a>, <a href="/search/astro-ph?searchtype=author&query=Traven%2C+G">G. Traven</a>, <a href="/search/astro-ph?searchtype=author&query=de+Jong%2C+R+S">R. S. de Jong</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="2001.09348v2-abstract-short" style="display: inline;"> Context. Several new multi-object spectrographs are currently planned or under construction that are capable of observing thousands of Galactic and extragalactic objects simultaneously. Aims. In this paper we present a probabilistic fibre-to-target assignment algorithm that takes spectrograph targeting constraints into account and is capable of dealing with multiple concurrent surveys. We presen… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.09348v2-abstract-full').style.display = 'inline'; document.getElementById('2001.09348v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.09348v2-abstract-full" style="display: none;"> Context. Several new multi-object spectrographs are currently planned or under construction that are capable of observing thousands of Galactic and extragalactic objects simultaneously. Aims. In this paper we present a probabilistic fibre-to-target assignment algorithm that takes spectrograph targeting constraints into account and is capable of dealing with multiple concurrent surveys. We present this algorithm using the 4-metre Multi-Object Spectroscopic Telescope (4MOST) as an example. Methods. The key idea of the proposed algorithm is to assign probabilities to fibre-target pairs. The assignment of probabilities takes the fibre positioner's capabilities and constraints into account. Additionally, these probabilities include requirements from surveys and take the required exposure time, number density variation, and angular clustering of targets across each survey into account. The main advantage of a probabilistic approach is that it allows for accurate and easy computation of the target selection function for the different surveys, which involves determining the probability of observing a target, given an input catalogue. Results. The probabilistic fibre-to-target assignment allows us to achieve maximally uniform completeness within a single field of view. The proposed algorithm maximises the fraction of successfully observed targets whilst minimising the selection bias as a function of exposure time. In the case of several concurrent surveys, the algorithm maximally satisfies the scientific requirements of each survey and no specific survey is penalised or prioritised. Conclusions. The algorithm presented is a proposed solution for the 4MOST project that allows for an unbiased targeting of many simultaneous surveys. With some modifications, the algorithm may also be applied to other multi-object spectroscopic surveys. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.09348v2-abstract-full').style.display = 'none'; document.getElementById('2001.09348v2-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> 4 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </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, 18 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 635, A101 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1912.09778">arXiv:1912.09778</a> <span> [<a href="https://arxiv.org/pdf/1912.09778">pdf</a>, <a href="https://arxiv.org/format/1912.09778">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> </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/10.1051/0004-6361/201937364">10.1051/0004-6361/201937364 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> From the bulge to the outer disc: StarHorse stellar parameters, distances, and extinctions for stars in APOGEE DR16 and other spectroscopic surveys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Queiroz%2C+A+B+A">A. B. A. Queiroz</a>, <a href="/search/astro-ph?searchtype=author&query=Anders%2C+F">F. Anders</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">C. Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Khalatyan%2C+A">A. Khalatyan</a>, <a href="/search/astro-ph?searchtype=author&query=Santiago%2C+B+X">B. X. Santiago</a>, <a href="/search/astro-ph?searchtype=author&query=Steinmetz%2C+M">M. Steinmetz</a>, <a href="/search/astro-ph?searchtype=author&query=Valentini%2C+M">M. Valentini</a>, <a href="/search/astro-ph?searchtype=author&query=Miglio%2C+A">A. Miglio</a>, <a href="/search/astro-ph?searchtype=author&query=Bossini%2C+D">D. Bossini</a>, <a href="/search/astro-ph?searchtype=author&query=Barbuy%2C+B">B. Barbuy</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">I. Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Minniti%2C+D">D. Minniti</a>, <a href="/search/astro-ph?searchtype=author&query=Hern%C3%A1ndez%2C+D+A+G">D. A. Garc铆a Hern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Schultheis%2C+M">M. Schultheis</a>, <a href="/search/astro-ph?searchtype=author&query=Beaton%2C+R+L">R. L. Beaton</a>, <a href="/search/astro-ph?searchtype=author&query=Beers%2C+T+C">T. C. Beers</a>, <a href="/search/astro-ph?searchtype=author&query=Bizyaev%2C+D">D. Bizyaev</a>, <a href="/search/astro-ph?searchtype=author&query=Brownstein%2C+J+R">J. R. Brownstein</a>, <a href="/search/astro-ph?searchtype=author&query=Cunha%2C+K">K. Cunha</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez-Trincado%2C+J+G">J. G. Fern谩ndez-Trincado</a>, <a href="/search/astro-ph?searchtype=author&query=Frinchaboy%2C+P+M">P. M. Frinchaboy</a>, <a href="/search/astro-ph?searchtype=author&query=Lane%2C+R+R">R. R. Lane</a>, <a href="/search/astro-ph?searchtype=author&query=Majewski%2C+S+R">S. R. Majewski</a>, <a href="/search/astro-ph?searchtype=author&query=Nataf%2C+D">D. Nataf</a>, <a href="/search/astro-ph?searchtype=author&query=Nitschelm%2C+C">C. Nitschelm</a> , et al. (5 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="1912.09778v3-abstract-short" style="display: inline;"> We combine high-resolution spectroscopic data from APOGEE-2 Survey Data Release 16 (DR16) with broad-band photometric data from several sources, as well as parallaxes from {\it Gaia} Data Release 2 (DR2). Using the Bayesian isochrone-fitting code {\tt StarHorse}, we derive distances, extinctions and astrophysical parameters for around 388,815 APOGEE stars, achieving typical distance uncertainties… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.09778v3-abstract-full').style.display = 'inline'; document.getElementById('1912.09778v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.09778v3-abstract-full" style="display: none;"> We combine high-resolution spectroscopic data from APOGEE-2 Survey Data Release 16 (DR16) with broad-band photometric data from several sources, as well as parallaxes from {\it Gaia} Data Release 2 (DR2). Using the Bayesian isochrone-fitting code {\tt StarHorse}, we derive distances, extinctions and astrophysical parameters for around 388,815 APOGEE stars, achieving typical distance uncertainties of $\sim 6\%$ for APOGEE giants, $\sim 2\%$ for APOGEE dwarfs, as well as extinction uncertainties of $\sim 0.07$ mag when all photometric information is available, and $\sim 0.17$ mag if optical photometry is missing. {\tt StarHorse} uncertainties vary with the input spectroscopic catalogue, with the available photometry, and with the parallax uncertainties. To illustrate the impact of our results, we show that, thanks to {\it Gaia} DR2 and the now larger sky coverage of APOGEE-2 (including APOGEE-South), we obtain an extended map of the Galactic plane, providing unprecedented coverage of the disk close to the Galactic mid-plane ($|Z_{Gal}|<1$ kpc) from the Galactic Centre out to $R_{\rm Gal}\sim 20$ kpc. The improvements in statistics as well as distance and extinction uncertainties unveil the presence of the bar in stellar density, as well as the striking chemical duality in the innermost regions of the disk, now clearly extending to the inner bulge. We complement this paper with distances and extinctions for stars in other public released spectroscopic surveys: 324,999 in GALAH DR2, 4,928,715 in LAMOST DR5, 408,894 in RAVE DR6, and 6,095 in GES DR3 <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.09778v3-abstract-full').style.display = 'none'; document.getElementById('1912.09778v3-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> 20 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 December, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2019. </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. 17 pages, 11 figures. Data products are available at https://data.aip.de/aqueiroz2020, (doi:10.17876/data/2020_2)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 638, A76 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1911.05221">arXiv:1911.05221</a> <span> [<a href="https://arxiv.org/pdf/1911.05221">pdf</a>, <a href="https://arxiv.org/format/1911.05221">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/stz3048">10.1093/mnras/stz3048 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The GALAH Survey: Temporal Chemical Enrichment of the Galactic Disk </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lin%2C+J">Jane Lin</a>, <a href="/search/astro-ph?searchtype=author&query=Asplund%2C+M">Martin Asplund</a>, <a href="/search/astro-ph?searchtype=author&query=Ting%2C+Y">Yuan-Sen Ting</a>, <a href="/search/astro-ph?searchtype=author&query=Casagrande%2C+L">Luca Casagrande</a>, <a href="/search/astro-ph?searchtype=author&query=Buder%2C+S">Sven Buder</a>, <a href="/search/astro-ph?searchtype=author&query=Bland-Hawthorn%2C+J">Joss Bland-Hawthorn</a>, <a href="/search/astro-ph?searchtype=author&query=Casey%2C+A+R">Andrew R. Casey</a>, <a href="/search/astro-ph?searchtype=author&query=De+Silva%2C+G+M">Gayandhi M. De Silva</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Orazi%2C+V">Valentina D'Orazi</a>, <a href="/search/astro-ph?searchtype=author&query=Freeman%2C+K+C">Ken C. Freeman</a>, <a href="/search/astro-ph?searchtype=author&query=Kos%2C+J">Janez Kos</a>, <a href="/search/astro-ph?searchtype=author&query=Lind%2C+K">K Lind</a>, <a href="/search/astro-ph?searchtype=author&query=Martell%2C+S+L">Sarah L. Martell</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+S">Sanjib Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Simpson%2C+J+D">Jeffrey D. Simpson</a>, <a href="/search/astro-ph?searchtype=author&query=Zwitter%2C+T">Toma啪 Zwitter</a>, <a href="/search/astro-ph?searchtype=author&query=Zucker%2C+D+B">Daniel B. Zucker</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=%C4%8Cotar%2C+K">Klemen 膶otar</a>, <a href="/search/astro-ph?searchtype=author&query=Hayden%2C+M">Michael Hayden</a>, <a href="/search/astro-ph?searchtype=author&query=Horner%2C+J">Jonti Horner</a>, <a href="/search/astro-ph?searchtype=author&query=Lewis%2C+G+F">Geraint F. Lewis</a>, <a href="/search/astro-ph?searchtype=author&query=Nordlander%2C+T">Thomas Nordlander</a>, <a href="/search/astro-ph?searchtype=author&query=Wyse%2C+R+F+G">Rosemary F. G. Wyse</a>, <a href="/search/astro-ph?searchtype=author&query=%C5%BDerjal%2C+M">Maru拧a 沤erjal</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="1911.05221v1-abstract-short" style="display: inline;"> We present isochrone ages and initial bulk metallicities ($\rm [Fe/H]_{bulk}$, by accounting for diffusion) of 163,722 stars from the GALAH Data Release 2, mainly composed of main sequence turn-off stars and subgiants ($\rm 7000 K>T_{eff}>4000 K$ and $\rm log g>3$ dex). The local age-metallicity relationship (AMR) is nearly flat but with significant scatter at all ages; the scatter is even higher… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.05221v1-abstract-full').style.display = 'inline'; document.getElementById('1911.05221v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.05221v1-abstract-full" style="display: none;"> We present isochrone ages and initial bulk metallicities ($\rm [Fe/H]_{bulk}$, by accounting for diffusion) of 163,722 stars from the GALAH Data Release 2, mainly composed of main sequence turn-off stars and subgiants ($\rm 7000 K>T_{eff}>4000 K$ and $\rm log g>3$ dex). The local age-metallicity relationship (AMR) is nearly flat but with significant scatter at all ages; the scatter is even higher when considering the observed surface abundances. After correcting for selection effects, the AMR appear to have intrinsic structures indicative of two star formation events, which we speculate are connected to the thin and thick disks in the solar neighborhood. We also present abundance ratio trends for 16 elements as a function of age, across different $\rm [Fe/H]_{bulk}$ bins. In general, we find the trends in terms of [X/Fe] vs age from our far larger sample to be compatible with studies based on small ($\sim$ 100 stars) samples of solar twins but we now extend it to both sub- and super-solar metallicities. The $伪$-elements show differing behaviour: the hydrostatic $伪$-elements O and Mg show a steady decline with time for all metallicities while the explosive $伪$-elements Si, Ca and Ti are nearly constant during the thin disk epoch (ages $\lessapprox $ 12 Gyr). The s-process elements Y and Ba show increasing [X/Fe] with time while the r-process element Eu have the opposite trend, thus favouring a primary production from sources with a short time-delay such as core-collapse supernovae over long-delay events such as neutron star mergers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.05221v1-abstract-full').style.display = 'none'; document.getElementById('1911.05221v1-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 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1910.12896">arXiv:1910.12896</a> <span> [<a href="https://arxiv.org/pdf/1910.12896">pdf</a>, <a href="https://arxiv.org/format/1910.12896">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> </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/stz3126">10.1093/mnras/stz3126 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Milky Way Analogues in MaNGA: Multi-Parameter Homogeneity and Comparison to the Milky Way </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Boardman%2C+N+F">Nicholas Fraser Boardman</a>, <a href="/search/astro-ph?searchtype=author&query=Zasowski%2C+G">Gail Zasowski</a>, <a href="/search/astro-ph?searchtype=author&query=Seth%2C+A">Anil Seth</a>, <a href="/search/astro-ph?searchtype=author&query=Newman%2C+J">Jeff Newman</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+B">Brett Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Bershady%2C+M">Matt Bershady</a>, <a href="/search/astro-ph?searchtype=author&query=Bird%2C+J">Jonathan Bird</a>, <a href="/search/astro-ph?searchtype=author&query=Chiappini%2C+C">Cristina Chiappini</a>, <a href="/search/astro-ph?searchtype=author&query=Fielder%2C+C">Catherine Fielder</a>, <a href="/search/astro-ph?searchtype=author&query=Fraser-McKelvie%2C+A">Amelia Fraser-McKelvie</a>, <a href="/search/astro-ph?searchtype=author&query=Jones%2C+A">Amy Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Licquia%2C+T">Tim Licquia</a>, <a href="/search/astro-ph?searchtype=author&query=Masters%2C+K">Karen Masters</a>, <a href="/search/astro-ph?searchtype=author&query=Minchev%2C+I">Ivan Minchev</a>, <a href="/search/astro-ph?searchtype=author&query=Schiavon%2C+R">Ricardo Schiavon</a>, <a href="/search/astro-ph?searchtype=author&query=Brownstein%2C+J">Joel Brownstein</a>, <a href="/search/astro-ph?searchtype=author&query=Drory%2C+N">Niv Drory</a>, <a href="/search/astro-ph?searchtype=author&query=Lane%2C+R">Richard Lane</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="1910.12896v2-abstract-short" style="display: inline;"> The Milky Way provides an ideal laboratory to test our understanding of galaxy evolution, owing to our ability to observe our Galaxy over fine scales. However, connecting the Galaxy to the wider galaxy population remains difficult, due to the challenges posed by our internal perspective and to the different observational techniques employed. Here, we present a sample of galaxies identified as Milk… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.12896v2-abstract-full').style.display = 'inline'; document.getElementById('1910.12896v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.12896v2-abstract-full" style="display: none;"> The Milky Way provides an ideal laboratory to test our understanding of galaxy evolution, owing to our ability to observe our Galaxy over fine scales. However, connecting the Galaxy to the wider galaxy population remains difficult, due to the challenges posed by our internal perspective and to the different observational techniques employed. Here, we present a sample of galaxies identified as Milky Way Analogs (MWAs) on the basis of their stellar masses and bulge-to-total ratios, observed as part of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. We analyse the galaxies in terms of their stellar kinematics and populations as well as their ionised gas contents. We find our sample to contain generally young stellar populations in their outskirts. However, we find a wide range of stellar ages in their central regions, and we detect central AGN-like or composite-like activity in roughly half of the sample galaxies, with the other half consisting of galaxies with central star-forming emission or emission consistent with old stars. We measure gradients in gas metallicity and stellar metallicity that are generally flatter in physical units than those measured for the Milky Way; however, we find far better agreement with the Milky Way when scaling gradients by galaxies' disc scale lengths. From this, we argue much of the discrepancy in metallicity gradients to be due to the relative compactness of the Milky Way, with differences in observing perspective also likely to be a factor. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.12896v2-abstract-full').style.display = 'none'; document.getElementById('1910.12896v2-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 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2019. </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">33 pages, 28 figures. Accepted by MNRAS. Definition of "old stars" from Hasselquist et al. 2019 corrected from 10 Gyr to 9 Gyr; results and discussion unchanged</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> MNRAS, Volume 491, p.3672-3701 (2020) </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Minchev%2C+I&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Minchev%2C+I&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Minchev%2C+I&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Minchev%2C+I&start=100" class="pagination-link " aria-label="Page 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