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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <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=Leto%2C+P&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Leto%2C+P&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Leto%2C+P&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol 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/2411.17689">arXiv:2411.17689</a> <span> [<a href="https://arxiv.org/pdf/2411.17689">pdf</a>, <a href="https://arxiv.org/format/2411.17689">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Searching for star-planet interactions in GJ 486 at radio wavelengths with the uGMRT </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pe%C3%B1a-Mo%C3%B1ino%2C+L">L. Pe帽a-Mo帽ino</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A9rez-Torres%2C+M">M. P茅rez-Torres</a>, <a href="/search/astro-ph?searchtype=author&query=Kansabanik%2C+D">D. Kansabanik</a>, <a href="/search/astro-ph?searchtype=author&query=Bl%C3%A1zquez-Calero%2C+G">G. Bl谩zquez-Calero</a>, <a href="/search/astro-ph?searchtype=author&query=Kavanagh%2C+R+D">R. D. Kavanagh</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B3mez%2C+J+F">J. F. G贸mez</a>, <a href="/search/astro-ph?searchtype=author&query=Mold%C3%B3n%2C+J">J. Mold贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Alberdi%2C+A">A. Alberdi</a>, <a href="/search/astro-ph?searchtype=author&query=Amado%2C+P+J">P. J. Amado</a>, <a href="/search/astro-ph?searchtype=author&query=Anglada%2C+G">G. Anglada</a>, <a href="/search/astro-ph?searchtype=author&query=Caballero%2C+J+A">J. A. Caballero</a>, <a href="/search/astro-ph?searchtype=author&query=Mohan%2C+A">A. Mohan</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Narang%2C+M">M. Narang</a>, <a href="/search/astro-ph?searchtype=author&query=Osorio%2C+M">M. Osorio</a>, <a href="/search/astro-ph?searchtype=author&query=Revilla%2C+D">D. Revilla</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</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="2411.17689v2-abstract-short" style="display: inline;"> We search for radio emission from star-planet interactions in the M-dwarf system GJ~486, which hosts an Earth-like planet. We observed the GJ~486 system with the upgraded Giant Metrewave Radio Telescope (uGMRT) from 550 to 750 MHz in nine different epochs, between October 2021 and February 2022, covering almost all orbital phases of GJ~486 b from different orbital cycles. We obtained radio images… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.17689v2-abstract-full').style.display = 'inline'; document.getElementById('2411.17689v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.17689v2-abstract-full" style="display: none;"> We search for radio emission from star-planet interactions in the M-dwarf system GJ~486, which hosts an Earth-like planet. We observed the GJ~486 system with the upgraded Giant Metrewave Radio Telescope (uGMRT) from 550 to 750 MHz in nine different epochs, between October 2021 and February 2022, covering almost all orbital phases of GJ~486 b from different orbital cycles. We obtained radio images and dynamic spectra of the total and circularly polarized intensity for each individual epoch We do not detect any quiescent radio emission in any epoch above 3$蟽$. Similarly, we do not detect any bursty emission in our dynamic spectra. While we cannot completely rule out that the absence of a radio detection is due to time variability of the radio emission, or to the maximum electron-cyclotron maser emission being below our observing range, this seems unlikely. We discuss two possible scenarios: an intrinsic dim radio signal, or alternatively, that the anisotropic beamed emission pointed away from the observer. If the non-detection of radio emission from star-planet interaction in GJ~486 is due to an intrinsically dim signal, this implies that, independently of whether the planet is magnetized or not, the mass-loss rate is small (\dot{M}_\star $\lesssim$ 0.3 \dot{M}_\sun) and that, concomitantly, the efficiency of the conversion of Poynting flux into radio emission must be low ($尾\lesssim 10^{-3}$). Free-free absorption effects are negligible, given the high value of the coronal temperature. Finally, if the anisotropic beaming pointed away from us, this would imply that GJ~486 has very low values of its magnetic obliquity and inclination. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.17689v2-abstract-full').style.display = 'none'; document.getElementById('2411.17689v2-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">v1</span> submitted 26 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.06383">arXiv:2409.06383</a> <span> [<a href="https://arxiv.org/pdf/2409.06383">pdf</a>, <a href="https://arxiv.org/format/2409.06383">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/10.1051/0004-6361/202451096">10.1051/0004-6361/202451096 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sifting the debris: Patterns in the SNR population with unsupervised ML methods </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Cecconello%2C+T">T. Cecconello</a>, <a href="/search/astro-ph?searchtype=author&query=Munari%2C+M">M. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Hopkins%2C+A">A. Hopkins</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Sciacca%2C+E">E. Sciacca</a>, <a href="/search/astro-ph?searchtype=author&query=Vizzari%2C+G">G. Vizzari</a>, <a href="/search/astro-ph?searchtype=author&query=De+Marco%2C+A">A. De Marco</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</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="2409.06383v1-abstract-short" style="display: inline;"> Supernova remnants (SNRs) carry vast amounts of mechanical and radiative energy that heavily influence the structural, dynamical, and chemical evolution of galaxies. To this day, more than 300 SNRs have been discovered in the Milky Way, exhibiting a wide variety of observational features. However, existing classification schemes are mainly based on their radio morphology. In this work, we introduc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.06383v1-abstract-full').style.display = 'inline'; document.getElementById('2409.06383v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.06383v1-abstract-full" style="display: none;"> Supernova remnants (SNRs) carry vast amounts of mechanical and radiative energy that heavily influence the structural, dynamical, and chemical evolution of galaxies. To this day, more than 300 SNRs have been discovered in the Milky Way, exhibiting a wide variety of observational features. However, existing classification schemes are mainly based on their radio morphology. In this work, we introduce a novel unsupervised deep learning pipeline to analyse a representative subsample of the Galactic SNR population ($\sim$ 50% of the total) with the aim of finding a connection between their multi-wavelength features and their physical properties. The pipeline involves two stages: (1) a representation learning stage, consisting of a convolutional autoencoder that feeds on imagery from infrared and radio continuum surveys (WISE 22$渭$m, Hi-GAL 70 $渭$m and SMGPS 30 cm) and produces a compact representation in a lower-dimensionality latent space; and (2) a clustering stage that seeks meaningful clusters in the latent space that can be linked to the physical properties of the SNRs and their surroundings. Our results suggest that this approach, when combined with an intermediate uniform manifold approximation and projection (UMAP) reprojection of the autoencoded embeddings into a more clusterable manifold, enables us to find reliable clusters. Despite a large number of sources being classified as outliers, most clusters relate to the presence of distinctive features, such as the distribution of infrared emission, the presence of radio shells and pulsar wind nebulae, and the existence of dust filaments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.06383v1-abstract-full').style.display = 'none'; document.getElementById('2409.06383v1-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in A&A. 17 pages, 11 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/2408.07727">arXiv:2408.07727</a> <span> [<a href="https://arxiv.org/pdf/2408.07727">pdf</a>, <a href="https://arxiv.org/ps/2408.07727">ps</a>, <a href="https://arxiv.org/format/2408.07727">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/10.1051/0004-6361/202450766">10.1051/0004-6361/202450766 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> MeerKAT reveals a ghostly thermal radio ring towards the Galactic Centre </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Filipovic%2C+M+D">M. D. Filipovic</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Cotton%2C+W+D">W. D. Cotton</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Camilo%2C+F">F. Camilo</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+S">S. Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Hopkins%2C+A+M">A. M. Hopkins</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Jarrett%2C+T">T. Jarrett</a>, <a href="/search/astro-ph?searchtype=author&query=Koribalski%2C+B">B. Koribalski</a>, <a href="/search/astro-ph?searchtype=author&query=Lazarevic%2C+S">S. Lazarevic</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Lundqvist%2C+P">P. Lundqvist</a>, <a href="/search/astro-ph?searchtype=author&query=Mackey%2C+J">J. Mackey</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Payne%2C+J">J. Payne</a>, <a href="/search/astro-ph?searchtype=author&query=Rowell%2C+G">G. Rowell</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Rizzo%2C+J+R">J. R. Rizzo</a>, <a href="/search/astro-ph?searchtype=author&query=Ruggeri%2C+A+C">A. C. Ruggeri</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.07727v1-abstract-short" style="display: inline;"> We present the serendipitous discovery of a new radio-continuum ring-like object nicknamed Kyklos (J1802-3353), with MeerKAT UHF and L-band observations. The radio ring, which resembles the recently discovered odd radio circles (ORCs), has a diameter of 80 arcsec and is located just 6 deg from the Galactic plane. However, Kyklos exhibits an atypical thermal radio-continuum spectrum (伪 = -0.1 +/- 0… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07727v1-abstract-full').style.display = 'inline'; document.getElementById('2408.07727v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.07727v1-abstract-full" style="display: none;"> We present the serendipitous discovery of a new radio-continuum ring-like object nicknamed Kyklos (J1802-3353), with MeerKAT UHF and L-band observations. The radio ring, which resembles the recently discovered odd radio circles (ORCs), has a diameter of 80 arcsec and is located just 6 deg from the Galactic plane. However, Kyklos exhibits an atypical thermal radio-continuum spectrum (伪 = -0.1 +/- 0.3), which led us to explore different possible formation scenarios. We concluded that a circumstellar shell around an evolved massive star, possibly a Wolf-Rayet, is the most convincing explanation with the present data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07727v1-abstract-full').style.display = 'none'; document.getElementById('2408.07727v1-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 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 5 figures, accepted in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.18462">arXiv:2404.18462</a> <span> [<a href="https://arxiv.org/pdf/2404.18462">pdf</a>, <a href="https://arxiv.org/format/2404.18462">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 class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1017/pasa.2024.84">10.1017/pasa.2024.84 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Self-supervised contrastive learning of radio data for source detection, classification and peculiar object discovery </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Cecconello%2C+T">T. Cecconello</a>, <a href="/search/astro-ph?searchtype=author&query=Palazzo%2C+S">S. Palazzo</a>, <a href="/search/astro-ph?searchtype=author&query=Hopkins%2C+A+M">A. M. Hopkins</a>, <a href="/search/astro-ph?searchtype=author&query=Gupta%2C+N">N. Gupta</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Filipovi%C4%87%2C+M+D">M. D. Filipovi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Ruggeri%2C+A+C">A. C. Ruggeri</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Vitello%2C+F">F. Vitello</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.18462v1-abstract-short" style="display: inline;"> New advancements in radio data post-processing are underway within the SKA precursor community, aiming to facilitate the extraction of scientific results from survey images through a semi-automated approach. Several of these developments leverage deep learning (DL) methodologies for diverse tasks, including source detection, object or morphology classification, and anomaly detection. Despite subst… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.18462v1-abstract-full').style.display = 'inline'; document.getElementById('2404.18462v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.18462v1-abstract-full" style="display: none;"> New advancements in radio data post-processing are underway within the SKA precursor community, aiming to facilitate the extraction of scientific results from survey images through a semi-automated approach. Several of these developments leverage deep learning (DL) methodologies for diverse tasks, including source detection, object or morphology classification, and anomaly detection. Despite substantial progress, the full potential of these methods often remains untapped due to challenges associated with training large supervised models, particularly in the presence of small and class-unbalanced labelled datasets. Self-supervised learning has recently established itself as a powerful methodology to deal with some of the aforementioned challenges, by directly learning a lower-dimensional representation from large samples of unlabelled data. The resulting model and data representation can then be used for data inspection and various downstream tasks if a small subset of labelled data is available. In this work, we explored contrastive learning methods to learn suitable radio data representation from unlabelled images taken from the ASKAP EMU and SARAO MeerKAT GPS surveys. We evaluated trained models and the obtained data representation over smaller labelled datasets, also taken from different radio surveys, in selected analysis tasks: source detection and classification, and search for objects with peculiar morphology. For all explored downstream tasks, we reported and discussed the benefits brought by self-supervised foundational models built on radio data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.18462v1-abstract-full').style.display = 'none'; document.getElementById('2404.18462v1-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 16 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Publ. Astron. Soc. Aust. 41 (2024) e085 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.04647">arXiv:2403.04647</a> <span> [<a href="https://arxiv.org/pdf/2403.04647">pdf</a>, <a href="https://arxiv.org/format/2403.04647">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> <p class="title is-5 mathjax"> The distance to CRL 618 through its radio expansion parallax </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Menten%2C+K+M">K. M. Menten</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</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="2403.04647v1-abstract-short" style="display: inline;"> CRL 618 is a post-AGB star that has started to ionize its ejecta. Its central HII region has been observed over the last 40 years and has steadily increased in flux density at radio wavelengths. In this paper, we present data that we obtained with the Very Large Array in its highest frequency band (43 GHz) in 2011 and compare these with archival data in the same frequency band from 1998. By applyi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.04647v1-abstract-full').style.display = 'inline'; document.getElementById('2403.04647v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.04647v1-abstract-full" style="display: none;"> CRL 618 is a post-AGB star that has started to ionize its ejecta. Its central HII region has been observed over the last 40 years and has steadily increased in flux density at radio wavelengths. In this paper, we present data that we obtained with the Very Large Array in its highest frequency band (43 GHz) in 2011 and compare these with archival data in the same frequency band from 1998. By applying the so-called expansion-parallax method, we are able to estimate an expansion rate of 4.0$\pm$0.4 mas yr$^{-1}$ along the major axis of the nebula and derive a distance of 1.1$\pm$0.2 kpc. Within errors, this distance estimation is in good agreement with the value of ~900 pc derived from the expansion of the optical lobes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.04647v1-abstract-full').style.display = 'none'; document.getElementById('2403.04647v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 March, 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">6 pages, 6 figures, accepted for publication on 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/2402.15232">arXiv:2402.15232</a> <span> [<a href="https://arxiv.org/pdf/2402.15232">pdf</a>, <a href="https://arxiv.org/format/2402.15232">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="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">stat.ML</span> </div> </div> <p class="title is-5 mathjax"> Classification of compact radio sources in the Galactic plane with supervised machine learning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Gordon%2C+Y">Y. Gordon</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%BCrkan%2C+G">G. G眉rkan</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Hopkins%2C+A+M">A. M. Hopkins</a>, <a href="/search/astro-ph?searchtype=author&query=Filipovi%C4%87%2C+M+D">M. D. Filipovi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Cecconello%2C+T">T. Cecconello</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="2402.15232v1-abstract-short" style="display: inline;"> Generation of science-ready data from processed data products is one of the major challenges in next-generation radio continuum surveys with the Square Kilometre Array (SKA) and its precursors, due to the expected data volume and the need to achieve a high degree of automated processing. Source extraction, characterization, and classification are the major stages involved in this process. In this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.15232v1-abstract-full').style.display = 'inline'; document.getElementById('2402.15232v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.15232v1-abstract-full" style="display: none;"> Generation of science-ready data from processed data products is one of the major challenges in next-generation radio continuum surveys with the Square Kilometre Array (SKA) and its precursors, due to the expected data volume and the need to achieve a high degree of automated processing. Source extraction, characterization, and classification are the major stages involved in this process. In this work we focus on the classification of compact radio sources in the Galactic plane using both radio and infrared images as inputs. To this aim, we produced a curated dataset of ~20,000 images of compact sources of different astronomical classes, obtained from past radio and infrared surveys, and novel radio data from pilot surveys carried out with the Australian SKA Pathfinder (ASKAP). Radio spectral index information was also obtained for a subset of the data. We then trained two different classifiers on the produced dataset. The first model uses gradient-boosted decision trees and is trained on a set of pre-computed features derived from the data, which include radio-infrared colour indices and the radio spectral index. The second model is trained directly on multi-channel images, employing convolutional neural networks. Using a completely supervised procedure, we obtained a high classification accuracy (F1-score>90%) for separating Galactic objects from the extragalactic background. Individual class discrimination performances, ranging from 60% to 75%, increased by 10% when adding far-infrared and spectral index information, with extragalactic objects, PNe and HII regions identified with higher accuracies. The implemented tools and trained models were publicly released, and made available to the radioastronomical community for future application on new radio data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.15232v1-abstract-full').style.display = 'none'; document.getElementById('2402.15232v1-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 15 figures, 9 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/2312.07275">arXiv:2312.07275</a> <span> [<a href="https://arxiv.org/pdf/2312.07275">pdf</a>, <a href="https://arxiv.org/format/2312.07275">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"> The SARAO MeerKAT 1.3 GHz Galactic Plane Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Goedhart%2C+S">S. Goedhart</a>, <a href="/search/astro-ph?searchtype=author&query=Cotton%2C+W+D">W. D. Cotton</a>, <a href="/search/astro-ph?searchtype=author&query=Camilo%2C+F">F. Camilo</a>, <a href="/search/astro-ph?searchtype=author&query=Thompson%2C+M+A">M. A. Thompson</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Bietenholz%2C+M">M. Bietenholz</a>, <a href="/search/astro-ph?searchtype=author&query=Woudt%2C+P+A">P. A. Woudt</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+L+D">L. D. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Buckley%2C+D+A+H">D. A. H. Buckley</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+H">H. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chibueze%2C+J+O">J. O. Chibueze</a>, <a href="/search/astro-ph?searchtype=author&query=Egbo%2C+D">D. Egbo</a>, <a href="/search/astro-ph?searchtype=author&query=Frank%2C+B+S">B. S. Frank</a>, <a href="/search/astro-ph?searchtype=author&query=Hoare%2C+M+G">M. G. Hoare</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Irabor%2C+T">T. Irabor</a>, <a href="/search/astro-ph?searchtype=author&query=Kraan-Korteweg%2C+R+C">R. C. Kraan-Korteweg</a>, <a href="/search/astro-ph?searchtype=author&query=Kurapati%2C+S">S. Kurapati</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Mutale%2C+M">M. Mutale</a> , et al. (105 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="2312.07275v2-abstract-short" style="display: inline;"> We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251掳$\le l \le$ 358掳and 2掳$\le l \le$ 61掳at $|b| \le 1.5掳$). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8" and a broadband RMS sensitivity of $\sim$10--20 $渭$ Jy/beam. Here we d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.07275v2-abstract-full').style.display = 'inline'; document.getElementById('2312.07275v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.07275v2-abstract-full" style="display: none;"> We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251掳$\le l \le$ 358掳and 2掳$\le l \le$ 61掳at $|b| \le 1.5掳$). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8" and a broadband RMS sensitivity of $\sim$10--20 $渭$ Jy/beam. Here we describe the first publicly available data release from SMGPS which comprises data cubes of frequency-resolved images over 908--1656 MHz, power law fits to the images, and broadband zeroth moment integrated intensity images. A thorough assessment of the data quality and guidance for future usage of the data products are given. Finally, we discuss the tremendous potential of SMGPS by showcasing highlights of the Galactic and extragalactic science that it permits. These highlights include the discovery of a new population of non-thermal radio filaments; identification of new candidate supernova remnants, pulsar wind nebulae and planetary nebulae; improved radio/mid-IR classification of rare Luminous Blue Variables and discovery of associated extended radio nebulae; new radio stars identified by Bayesian cross-matching techniques; the realisation that many of the largest radio-quiet WISE HII region candidates are not true HII regions; and a large sample of previously undiscovered background HI galaxies in the Zone of Avoidance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.07275v2-abstract-full').style.display = 'none'; document.getElementById('2312.07275v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 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">Accepted for publication in MNRAS. The data release is live and links can be found in the Data Availability Statement in the paper</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.03922">arXiv:2310.03922</a> <span> [<a href="https://arxiv.org/pdf/2310.03922">pdf</a>, <a href="https://arxiv.org/format/2310.03922">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </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/10.1051/0004-6361/202347845">10.1051/0004-6361/202347845 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multi-year characterisation of the broad-band emission from the intermittent extreme BL Lac 1ES~2344+514 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Abe%2C+H">H. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+S">S. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Acciari%2C+V+A">V. A. Acciari</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Aniello%2C+T">T. Aniello</a>, <a href="/search/astro-ph?searchtype=author&query=Ansoldi%2C+S">S. Ansoldi</a>, <a href="/search/astro-ph?searchtype=author&query=Antonelli%2C+L+A">L. A. Antonelli</a>, <a href="/search/astro-ph?searchtype=author&query=Engels%2C+A+A">A. Arbet Engels</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Artero%2C+M">M. Artero</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+K">K. Asano</a>, <a href="/search/astro-ph?searchtype=author&query=Baack%2C+D">D. Baack</a>, <a href="/search/astro-ph?searchtype=author&query=Babi%C4%87%2C+A">A. Babi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Baquero%2C+A">A. Baquero</a>, <a href="/search/astro-ph?searchtype=author&query=de+Almeida%2C+U+B">U. Barres de Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Batkovi%C4%87%2C+I">I. Batkovi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Baxter%2C+J">J. Baxter</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+J+B">J. Becerra Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+E">E. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Bernete%2C+J">J. Bernete</a>, <a href="/search/astro-ph?searchtype=author&query=Berti%2C+A">A. Berti</a>, <a href="/search/astro-ph?searchtype=author&query=Besenrieder%2C+J">J. Besenrieder</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=Biland%2C+A">A. Biland</a>, <a href="/search/astro-ph?searchtype=author&query=Blanch%2C+O">O. Blanch</a> , et al. (210 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="2310.03922v1-abstract-short" style="display: inline;"> The BL Lac 1ES 2344+514 is known for temporary extreme properties (e.g., a shift of the synchrotron SED peak energy $谓_{synch,p}$ above 1keV). While those extreme states were so far observed only during high flux levels, additional multi-year observing campaigns are required to achieve a coherent picture. Here, we report the longest investigation of the source from radio to VHE performed so far, f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.03922v1-abstract-full').style.display = 'inline'; document.getElementById('2310.03922v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.03922v1-abstract-full" style="display: none;"> The BL Lac 1ES 2344+514 is known for temporary extreme properties (e.g., a shift of the synchrotron SED peak energy $谓_{synch,p}$ above 1keV). While those extreme states were so far observed only during high flux levels, additional multi-year observing campaigns are required to achieve a coherent picture. Here, we report the longest investigation of the source from radio to VHE performed so far, focusing on a systematic characterisation of the intermittent extreme states. While our results confirm that 1ES 2344+514 typically exhibits $谓_{synch,p}>$1keV during elevated flux periods, we also find periods where the extreme state coincides with low flux activity. A strong spectral variability thus happens in the quiescent state, and is likely caused by an increase of the electron acceleration efficiency without a change in the electron injection luminosity. We also report a strong X-ray flare (among the brightest for 1ES 2344+514) without a significant shift of $谓_{synch,p}$. During this particular flare, the X-ray spectrum is among the softest of the campaign. It unveils complexity in the spectral evolution, where the common harder-when-brighter trend observed in BL Lacs is violated. During a low and hard X-ray state, we find an excess of the UV flux with respect to an extrapolation of the X-ray spectrum to lower energies. This UV excess implies that at least two regions contribute significantly to the infrared/optical/ultraviolet/X-ray emission. Using the simultaneous MAGIC, XMM-Newton, NuSTAR, and AstroSat observations, we argue that a region possibly associated with the 10 GHz radio core may explain such an excess. Finally, we investigate a VHE flare, showing an absence of simultaneous variability in the 0.3-2keV band. Using a time-dependent leptonic modelling, we show that this behaviour, in contradiction to single-zone scenarios, can instead be explained by a two-component model. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.03922v1-abstract-full').style.display = 'none'; document.getElementById('2310.03922v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 October, 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 & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 682, A114 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.11851">arXiv:2307.11851</a> <span> [<a href="https://arxiv.org/pdf/2307.11851">pdf</a>, <a href="https://arxiv.org/format/2307.11851">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346980">10.1051/0004-6361/202346980 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The rich molecular environment of the luminous blue variable star AFGL 2298 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Rizzo%2C+J+R">J. R. Rizzo</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</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="2307.11851v1-abstract-short" style="display: inline;"> We investigated the molecular environment of AFGL 2298, an obscured Galactic Luminous blue variable (LBV) star which hosts a highly structured circumstellar environment with hints of multiple mass-loss events in the last few $10^4$ a. We present spectral line observations of AFGL 2298 at 1 and 3 mm performed with the IRAM 30m radio telescope. Furthermore, we report the detection of several carbon-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.11851v1-abstract-full').style.display = 'inline'; document.getElementById('2307.11851v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.11851v1-abstract-full" style="display: none;"> We investigated the molecular environment of AFGL 2298, an obscured Galactic Luminous blue variable (LBV) star which hosts a highly structured circumstellar environment with hints of multiple mass-loss events in the last few $10^4$ a. We present spectral line observations of AFGL 2298 at 1 and 3 mm performed with the IRAM 30m radio telescope. Furthermore, we report the detection of several carbon- and nitrogen- bearing species (CO, $^{13}$CO, C$^{18}$O, C$^{17}$O, HCO$^+$, HCN, HNC, H$^{13}$CO$^+$, CN, N$_2$H$^+$, and C$_2$H) in the surroundings of AFGL 2298. In addition, we identified three velocity components that clearly stand out from the Galactic background. The morphology, kinematics, masses and isotopic ratios, together with a comparative study of the fractional abundances, lead us to suggest that two of these components (36 and 70 km/s) have a stellar origin. The other component (46 km/s) most likely traces swept-up interstellar material, probably harbouring also a photon-dominated region. The first inventory of the circumstellar molecular gas around AFGL 2298 is provided. The results are compatible with the hypothesis of former mass-loss events, produced before the one that created the infrared nebula. There are chemical hints of the presence of ejected stellar material, and also swept up gas. These findings will help to better understand the mass-loss history of this class of evolved massive stars, which heavily influence the overall chemical evolution of the Galaxy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.11851v1-abstract-full').style.display = 'none'; document.getElementById('2307.11851v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 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">Accepted to Astronomy and Astrophysics. 15 pages, 4 tables, 11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 678, A55 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.00809">arXiv:2305.00809</a> <span> [<a href="https://arxiv.org/pdf/2305.00809">pdf</a>, <a href="https://arxiv.org/format/2305.00809">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="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> <p class="title is-5 mathjax"> Star-Planet Interaction at radio wavelengths in YZ Ceti: Inferring planetary magnetic field </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">Corrado Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Biswas%2C+A">Ayan Biswas</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">Grazia Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Busa%2C+I">Innocenza Busa</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">Francesco Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+B">Barnali Das</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Perez-Torres%2C+M">Miguel Perez-Torres</a>, <a href="/search/astro-ph?searchtype=author&query=Wade%2C+G+A">Gregg A. Wade</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">Cristobal Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">Carla S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">Filomena Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">Adriano Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">Sara Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">Simone Riggi</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="2305.00809v1-abstract-short" style="display: inline;"> In exoplanetary systems, the interaction between the central star and the planet can trigger Auroral Radio Emission (ARE), due to the Electron Cyclotron Maser mechanism. The high brightness temperature of this emission makes it visible at large distances, opening new opportunities to study exoplanets and to search for favourable conditions for the development of extra-terrestrial life, as magnetic… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.00809v1-abstract-full').style.display = 'inline'; document.getElementById('2305.00809v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.00809v1-abstract-full" style="display: none;"> In exoplanetary systems, the interaction between the central star and the planet can trigger Auroral Radio Emission (ARE), due to the Electron Cyclotron Maser mechanism. The high brightness temperature of this emission makes it visible at large distances, opening new opportunities to study exoplanets and to search for favourable conditions for the development of extra-terrestrial life, as magnetic fields act as a shield that protects life against external particles and influences the evolution of the planetary atmospheres. In the last few years, we started an observational campaign to observe a sample of nearby M-type stars known to host exoplanets with the aim to detect ARE. We observed YZ Ceti with the upgraded Giant Metrewave Radio Telescope (uGMRT) in band 4 (550-900 MHz) nine times over a period of five months. We detected radio emission four times, two of which with high degree of circular polarization. With statistical considerations we exclude the possibility of flares due to stellar magnetic activity. Instead, when folding the detections to the orbital phase of the closest planet YZ Cet b, they are at positions where we would expect ARE due to star-planet interaction (SPI) in sub-Alfvenic regime. With a degree of confidence higher than 4.37 sigma, YZ Cet is the first extrasolar systems with confirmed SPI at radio wavelengths. Modelling the ARE, we estimate a magnetic field for the star of about 2.4 kG and we find that the planet must have a magnetosphere. The lower limit for the polar magnetic field of the planet is 0.4 G. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.00809v1-abstract-full').style.display = 'none'; document.getElementById('2305.00809v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 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">11 pages, 7 figures, submitted to ApJ Letters in March 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/2210.14746">arXiv:2210.14746</a> <span> [<a href="https://arxiv.org/pdf/2210.14746">pdf</a>, <a href="https://arxiv.org/format/2210.14746">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac3123">10.1093/mnras/stac3123 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Testing a scaling relation between coherent radio emission and physical parameters of hot magnetic stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Das%2C+B">Barnali Das</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Shultz%2C+M+E">Matt E. Shultz</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Mikul%C3%A1%C5%A1ek%2C+Z">Zden臎k Mikul谩拧ek</a>, <a href="/search/astro-ph?searchtype=author&query=Petit%2C+V">V茅ronique Petit</a>, <a href="/search/astro-ph?searchtype=author&query=Wade%2C+G+A">Gregg A. Wade</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.14746v1-abstract-short" style="display: inline;"> Coherent radio emission via electron cyclotron maser emission (ECME) from hot magnetic stars was discovered more than two decades ago, but the physical conditions that make the generation of ECME favourable remain uncertain. Only recently was an empirical relation, connecting ECME luminosity with the stellar magnetic field and temperature, proposed to explain what makes a hot magnetic star capable… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.14746v1-abstract-full').style.display = 'inline'; document.getElementById('2210.14746v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.14746v1-abstract-full" style="display: none;"> Coherent radio emission via electron cyclotron maser emission (ECME) from hot magnetic stars was discovered more than two decades ago, but the physical conditions that make the generation of ECME favourable remain uncertain. Only recently was an empirical relation, connecting ECME luminosity with the stellar magnetic field and temperature, proposed to explain what makes a hot magnetic star capable of producing ECME. This relation was, however, obtained with just fourteen stars. Therefore, it is important to examine whether this relation is robust. With the aim of testing the robustness, we conducted radio observations of five hot magnetic stars. This led to the discovery of three more stars producing ECME. We find that the proposed scaling relation remains valid after the addition of the newly discovered stars. However we discovered that the magnetic field and effective temperature correlate for $T_\mathrm{eff}\lesssim 16$ kK (likely an artifact of the small sample size), rendering the proposed connection between ECME luminosity and $T_\mathrm{eff}$ unreliable. By examining the empirical relation in light of the scaling law for incoherent radio emission, we arrive at the conclusion that both types of emission are powered by the same magnetospheric phenomenon. Like the incoherent emission, coherent radio emission is indifferent to $T_\mathrm{eff}$ for late-B and A-type stars, but $T_\mathrm{eff}$ appears to become important for early-B type stars, possibly due to higher absorption, or, higher plasma density at the emission sites suppressing the production of the emission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.14746v1-abstract-full').style.display = 'none'; document.getElementById('2210.14746v1-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 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 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/2210.09774">arXiv:2210.09774</a> <span> [<a href="https://arxiv.org/pdf/2210.09774">pdf</a>, <a href="https://arxiv.org/format/2210.09774">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/10.3847/2041-8213/ac9b10">10.3847/2041-8213/ac9b10 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First detection of silicon-bearing molecules in $畏$ Car </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Rizzo%2C+J+R">J. R. Rizzo</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Quintana-Lacaci%2C+G">G. Quintana-Lacaci</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Sciacca%2C+E">E. Sciacca</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.09774v1-abstract-short" style="display: inline;"> We present ALMA band 6 observations of the luminous blue variable Eta Car, obtained within the ALMAGAL program. We report SiO J=5-4, SiS J=12-11 and SiN N=5-4 emission in the equatorial region of the Homunculus nebula, constituting the first detection of silicon- and sulphur-bearing molecules in the outskirts of a highly evolved, early-type massive star. SiO, SiS and SiN trace a clumpy equatorial… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.09774v1-abstract-full').style.display = 'inline'; document.getElementById('2210.09774v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.09774v1-abstract-full" style="display: none;"> We present ALMA band 6 observations of the luminous blue variable Eta Car, obtained within the ALMAGAL program. We report SiO J=5-4, SiS J=12-11 and SiN N=5-4 emission in the equatorial region of the Homunculus nebula, constituting the first detection of silicon- and sulphur-bearing molecules in the outskirts of a highly evolved, early-type massive star. SiO, SiS and SiN trace a clumpy equatorial ring that surrounds the central binary at a projected distance of 2 arcsec, delineating the inner rims of the butterfly-shaped dusty region. The formation of silicon-bearing compounds is presumably related to the continuous recycling of dust due to the variable wind regime of Eta Car, that destroys grains and releases silicon back to gas phase. We discuss possible formation routes for the observed species, contextualizing them within the current molecular inventory of Eta Car. We find that the SiO and SiS fractional abundances in localised clumps of the ring, $6.7\times10^{-9}$ and $1.2\times10^{-8}$ respectively, are exceptionally lower than those measured in C- and O-rich AGB stars and cool supergiants; while the higher SiN abundance, $3.6\times10^{-8}$, evidences the nitrogen-rich chemistry of the ejecta. These abundances must be regarded as strict upper limits, since the distribution of H2 in the Homunculus is unknown. In any case, these findings shed new light onto the peculiar molecular ecosystem of Eta Car, and establish its surroundings as a new laboratory to investigate the lifecycle of silicate dust in extreme astrophysical conditions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.09774v1-abstract-full').style.display = 'none'; document.getElementById('2210.09774v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 7 figures. Accepted in ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.14075">arXiv:2207.14075</a> <span> [<a href="https://arxiv.org/pdf/2207.14075">pdf</a>, <a href="https://arxiv.org/ps/2207.14075">ps</a>, <a href="https://arxiv.org/format/2207.14075">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac2163">10.1093/mnras/stac2163 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery and origin of the radio emission from the multiple stellar system KQVel </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Shultz%2C+M+E">M. E. Shultz</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Fossati%2C+L">L. Fossati</a>, <a href="/search/astro-ph?searchtype=author&query=Pillitteri%2C+I">I. Pillitteri</a>, <a href="/search/astro-ph?searchtype=author&query=Krticka%2C+J">J. Krticka</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Catanzaro%2C+G">G. Catanzaro</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Giarrusso%2C+M">M. Giarrusso</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Owocki%2C+S+P">S. P. Owocki</a>, <a href="/search/astro-ph?searchtype=author&query=Postnov%2C+K+A">K. A. Postnov</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Robrade%2C+J">J. Robrade</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.14075v1-abstract-short" style="display: inline;"> KQVel is a binary system composed of a slowly rotating magnetic Ap star with a companion of unknown nature. In this paper, we report the detection of its radio emission. We conducted a multi-frequency radio campaign using the ATCA interferometer (band-names: 16cm, 4cm, and 15mm). The target was detected in all bands. The most obvious explanation for the radio emission is that it originates in the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.14075v1-abstract-full').style.display = 'inline'; document.getElementById('2207.14075v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.14075v1-abstract-full" style="display: none;"> KQVel is a binary system composed of a slowly rotating magnetic Ap star with a companion of unknown nature. In this paper, we report the detection of its radio emission. We conducted a multi-frequency radio campaign using the ATCA interferometer (band-names: 16cm, 4cm, and 15mm). The target was detected in all bands. The most obvious explanation for the radio emission is that it originates in the magnetosphere of the Ap star, but this is shown unfeasible. The known stellar parameters of the Ap star enable us to exploit the scaling relationship for non-thermal gyro-synchrotron emission from early-type magnetic stars. This is a general relation demonstrating how radio emission from stars with centrifugal magnetospheres is supported by rotation. Using KQVel's parameters the predicted radio luminosity is more than five orders of magnitudes lower than the measured one. The extremely long rotation period rules out the Ap star as the source of the observed radio emission. Other possible explanations for the radio emission from KQVel, involving its unknown companion, have been explored. A scenario that matches the observed features (i.e. radio luminosity and spectrum, correlation to X-rays) is a hierarchical stellar system, where the possible companion of the magnetic star is a close binary (possibly of RSCVn type) with at least one magnetically active late-type star. To be compatible with the total mass of the system, the last scenario places strong constraints on the orbital inclination of the KQVel stellar system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.14075v1-abstract-full').style.display = 'none'; document.getElementById('2207.14075v1-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 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to MNRAS; 16 pages, 9 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/2207.07571">arXiv:2207.07571</a> <span> [<a href="https://arxiv.org/pdf/2207.07571">pdf</a>, <a href="https://arxiv.org/format/2207.07571">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 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/10.20371/INAF/TechRep/149">10.20371/INAF/TechRep/149 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Towards coordinated site monitoring and common strategies for mitigation of Radio Frequency Interference at the Italian radio telescopes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zanichelli%2C+A">Alessandra Zanichelli</a>, <a href="/search/astro-ph?searchtype=author&query=Serra%2C+G">Giampaolo Serra</a>, <a href="/search/astro-ph?searchtype=author&query=Mack%2C+K">Karl-Heinz Mack</a>, <a href="/search/astro-ph?searchtype=author&query=Nicotra%2C+G">Gaetano Nicotra</a>, <a href="/search/astro-ph?searchtype=author&query=Bartolini%2C+M">Marco Bartolini</a>, <a href="/search/astro-ph?searchtype=author&query=Cantini%2C+F">Federico Cantini</a>, <a href="/search/astro-ph?searchtype=author&query=De+Biaggi%2C+M">Matteo De Biaggi</a>, <a href="/search/astro-ph?searchtype=author&query=Gaudiomonte%2C+F">Francesco Gaudiomonte</a>, <a href="/search/astro-ph?searchtype=author&query=Bortolotti%2C+C">Claudio Bortolotti</a>, <a href="/search/astro-ph?searchtype=author&query=Roma%2C+M">Mauro Roma</a>, <a href="/search/astro-ph?searchtype=author&query=Poppi%2C+S">Sergio Poppi</a>, <a href="/search/astro-ph?searchtype=author&query=Bedosti%2C+F">Francesco Bedosti</a>, <a href="/search/astro-ph?searchtype=author&query=Righini%2C+S">Simona Righini</a>, <a href="/search/astro-ph?searchtype=author&query=Bolli%2C+P">Pietro Bolli</a>, <a href="/search/astro-ph?searchtype=author&query=Orlati%2C+A">Andrea Orlati</a>, <a href="/search/astro-ph?searchtype=author&query=Ambrosini%2C+R">Roberto Ambrosini</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">Carla Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Buttu%2C+M">Marco Buttu</a>, <a href="/search/astro-ph?searchtype=author&query=Cassaro%2C+P">Pietro Cassaro</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Mattana%2C+A">Andrea Mattana</a>, <a href="/search/astro-ph?searchtype=author&query=Migoni%2C+C">Carlo Migoni</a>, <a href="/search/astro-ph?searchtype=author&query=Moscadelli%2C+L">Luca Moscadelli</a>, <a href="/search/astro-ph?searchtype=author&query=Platania%2C+P+R">Pier Raffaele Platania</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">Corrado Trigilio</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.07571v1-abstract-short" style="display: inline;"> We present a project to implement a national common strategy for the mitigation of the steadily deteriorating Radio Frequency Interference (RFI) situation at the Italian radio telescopes. The project involves the Medicina, Noto, and Sardinia dish antennas and comprised the definition of a coordinated plan for site monitoring as well as the implementation of state-of-the-art hardware and software t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07571v1-abstract-full').style.display = 'inline'; document.getElementById('2207.07571v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.07571v1-abstract-full" style="display: none;"> We present a project to implement a national common strategy for the mitigation of the steadily deteriorating Radio Frequency Interference (RFI) situation at the Italian radio telescopes. The project involves the Medicina, Noto, and Sardinia dish antennas and comprised the definition of a coordinated plan for site monitoring as well as the implementation of state-of-the-art hardware and software tools for RFI mitigation. Coordinated monitoring of frequency bands up to 40 GHz has been performed by means of continuous observations and dedicated measurement campaigns with fixed stations and mobile laboratories. Measurements were executed on the frequency bands allocated to the radio astronomy and space research service for shared or exclusive use and on the wider ones employed by the current and under-development receivers at the telescopes. Results of the monitoring campaigns provide a reference scenario useful to evaluate the evolution of the interference situation at the telescopes sites and a case series to test and improve the hardware and software tools we conceived to counteract radio frequency interference. We developed a multi-purpose digital backend for high spectral and time resolution observations over large bandwidths. Observational results demonstrate that the spectrometer robustness and sensitivity enable the efficient detection and analysis of interfering signals in radio astronomical data. A prototype off-line software tool for interference detection and flagging has been also implemented. This package is capable to handle the huge amount of data delivered by the most modern instrumentation on board of the Italian radio telecsopes, like dense focal plane arrays, and its modularity easen the integration of new algorithms and the re-usability in different contexts or telescopes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.07571v1-abstract-full').style.display = 'none'; document.getElementById('2207.07571v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">39 pages, 10 Figures and 7 Tables. INAF Technical Report n. 149 (2022). http://hdl.handle.net/20.500.12386/32081</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.05449">arXiv:2202.05449</a> <span> [<a href="https://arxiv.org/pdf/2202.05449">pdf</a>, <a href="https://arxiv.org/ps/2202.05449">ps</a>, <a href="https://arxiv.org/format/2202.05449">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac341">10.1093/mnras/stac341 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Centrifugal breakout reconnection as the electron acceleration mechanism powering the radio magnetospheres of early-type stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Owocki%2C+S+P">Stanley P Owocki</a>, <a href="/search/astro-ph?searchtype=author&query=Shultz%2C+M+E">Matt E. Shultz</a>, <a href="/search/astro-ph?searchtype=author&query=ud-Doula%2C+A">Asif ud-Doula</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">Poonam Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+B">Barnali Das</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paulo Leto</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2202.05449v1-abstract-short" style="display: inline;"> Magnetic B-stars often exhibit circularly polarized radio emission thought to arise from gyrosynchrotron emission by energetic electrons trapped in the circumstellar magnetosphere. Recent empirical analyses show that the onset and strength of the observed radio emission scale with both the magnetic field strength and the stellar rotation rate. This challenges the existing paradigm that the energet… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.05449v1-abstract-full').style.display = 'inline'; document.getElementById('2202.05449v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.05449v1-abstract-full" style="display: none;"> Magnetic B-stars often exhibit circularly polarized radio emission thought to arise from gyrosynchrotron emission by energetic electrons trapped in the circumstellar magnetosphere. Recent empirical analyses show that the onset and strength of the observed radio emission scale with both the magnetic field strength and the stellar rotation rate. This challenges the existing paradigm that the energetic electrons are accelerated in the current sheet between opposite-polarity field lines in the outer regions of magnetised stellar winds, which includes no role for stellar rotation. Building on recent success in explaining a similar rotation-field dependence of H$伪$ line emission in terms of a model in which magnetospheric density is regulated by centrifugal breakout (CBO), we examine here the potential role of the associated CBO-driven magnetic reconnection in accelerating the electrons that emit the observed gyrosynchrotron radio. We show in particular that the theoretical scalings for energy production by CBO reconnection match well the empirical trends for observed radio luminosity, with a suitably small, nearly constant conversion efficiency $蔚\approx 10^{-8}$. We summarize the distinct advantages of our CBO scalings over previous associations with an electromotive force, and discuss the potential implications of CBO processes for X-rays and other observed characteristics of rotating magnetic B-stars with centrifugal magnetospheres. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.05449v1-abstract-full').style.display = 'none'; document.getElementById('2202.05449v1-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 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 6 pages, accepted for publication in Monthly Notices of the Royal Astronomical Society</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.05512">arXiv:2201.05512</a> <span> [<a href="https://arxiv.org/pdf/2201.05512">pdf</a>, <a href="https://arxiv.org/ps/2201.05512">ps</a>, <a href="https://arxiv.org/format/2201.05512">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac136">10.1093/mnras/stac136 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> MOBSTER -- VI. The crucial influence of rotation on the radio magnetospheres of hot stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shultz%2C+M+E">M. E. Shultz</a>, <a href="/search/astro-ph?searchtype=author&query=Owocki%2C+S+P">S. P. Owocki</a>, <a href="/search/astro-ph?searchtype=author&query=ud-Doula%2C+A">A. ud-Doula</a>, <a href="/search/astro-ph?searchtype=author&query=Biswas%2C+A">A. Biswas</a>, <a href="/search/astro-ph?searchtype=author&query=Bohlender%2C+D">D. Bohlender</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+P">P. Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+B">B. Das</a>, <a href="/search/astro-ph?searchtype=author&query=David-Uraz%2C+A">A. David-Uraz</a>, <a href="/search/astro-ph?searchtype=author&query=Khalack%2C+V">V. Khalack</a>, <a href="/search/astro-ph?searchtype=author&query=Kochukhov%2C+O">O. Kochukhov</a>, <a href="/search/astro-ph?searchtype=author&query=Landstreet%2C+J+D">J. D. Landstreet</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Monin%2C+D">D. Monin</a>, <a href="/search/astro-ph?searchtype=author&query=Neiner%2C+C">C. Neiner</a>, <a href="/search/astro-ph?searchtype=author&query=Rivinius%2C+T">Th. Rivinius</a>, <a href="/search/astro-ph?searchtype=author&query=Wade%2C+G+A">G. A. Wade</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="2201.05512v1-abstract-short" style="display: inline;"> Numerous magnetic hot stars exhibit gyrosynchrotron radio emission. The source electrons were previously thought to be accelerated to relativistic velocities in the current sheet formed in the middle magnetosphere by the wind opening magnetic field lines. However, a lack of dependence of radio luminosity on the wind power, and a strong dependence on rotation, has recently challenged this paradigm.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.05512v1-abstract-full').style.display = 'inline'; document.getElementById('2201.05512v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.05512v1-abstract-full" style="display: none;"> Numerous magnetic hot stars exhibit gyrosynchrotron radio emission. The source electrons were previously thought to be accelerated to relativistic velocities in the current sheet formed in the middle magnetosphere by the wind opening magnetic field lines. However, a lack of dependence of radio luminosity on the wind power, and a strong dependence on rotation, has recently challenged this paradigm. We have collected all radio measurements of magnetic early-type stars available in the literature. When constraints on the magnetic field and/or the rotational period are not available, we have determined these using previously unpublished spectropolarimetric and photometric data. The result is the largest sample of magnetic stars with radio observations that has yet been analyzed: 131 stars with rotational and magnetic constraints, of which 50 are radio-bright. We confirm an obvious dependence of gyrosynchrotron radiation on rotation, and furthermore find that accounting for rotation neatly separates stars with and without detected radio emission. There is a close correlation between H$伪$ emission strength and radio luminosity. These factors suggest that radio emission may be explained by the same mechanism responsible for H$伪$ emission from centrifugal magnetospheres, i.e. centrifugal breakout (CBO), however, whereas the H$伪$-emitting magnetosphere probes the cool plasma before breakout, radio emission is a consequence of electrons accelerated in centrifugally-driven magnetic reconnection. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.05512v1-abstract-full').style.display = 'none'; document.getElementById('2201.05512v1-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">47 pages (16 pages plus appendices), 43 figures, 9 tables, 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/2107.11995">arXiv:2107.11995</a> <span> [<a href="https://arxiv.org/pdf/2107.11995">pdf</a>, <a href="https://arxiv.org/ps/2107.11995">ps</a>, <a href="https://arxiv.org/format/2107.11995">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> </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/stab2168">10.1093/mnras/stab2168 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A scaling relationship for non-thermal radio emission from ordered magnetospheres: from the top of the Main Sequence to planets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Krticka%2C+J">J. Krticka</a>, <a href="/search/astro-ph?searchtype=author&query=Fossati%2C+L">L. Fossati</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Shultz%2C+M+E">M. E. Shultz</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Pillitteri%2C+I">I. Pillitteri</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Todt%2C+H">H. Todt</a>, <a href="/search/astro-ph?searchtype=author&query=Giarrusso%2C+M">M. Giarrusso</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Robrade%2C+J">J. Robrade</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</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="2107.11995v1-abstract-short" style="display: inline;"> In this paper, we present the analysis of incoherent non-thermal radio emission from a sample of hot magnetic stars, ranging from early-B to early-A spectral type. Spanning a wide range of stellar parameters and wind properties, these stars display a commonality in their radio emission which presents new challenges to the wind scenario as originally conceived. It was thought that relativistic elec… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.11995v1-abstract-full').style.display = 'inline'; document.getElementById('2107.11995v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.11995v1-abstract-full" style="display: none;"> In this paper, we present the analysis of incoherent non-thermal radio emission from a sample of hot magnetic stars, ranging from early-B to early-A spectral type. Spanning a wide range of stellar parameters and wind properties, these stars display a commonality in their radio emission which presents new challenges to the wind scenario as originally conceived. It was thought that relativistic electrons, responsible for the radio emission, originate in current sheets formed where the wind opens the magnetic field lines. However, the true mass-loss rates from the cooler stars are too small to explain the observed non-thermal broadband radio spectra. Instead, we suggest the existence of a radiation belt located inside the inner-magnetosphere, similar to that of Jupiter. Such a structure explains the overall indifference of the broadband radio emissions on wind mass-loss rates. Further, correlating the radio luminosities from a larger sample of magnetic stars with their stellar parameters, the combined roles of rotation and magnetic properties have been empirically determined. Finally, our sample of early-type magnetic stars suggests a scaling relationship between the non-thermal radio luminosity and the electric voltage induced by the magnetosphere's co-rotation, which appears to hold for a broader range of stellar types with dipole-dominated magnetospheres (like the cases of the planet Jupiter and the ultra-cool dwarf stars and brown dwarfs). We conclude that well-ordered and stable rotating magnetospheres share a common physical mechanism for supporting the generation of non-thermal electrons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.11995v1-abstract-full').style.display = 'none'; document.getElementById('2107.11995v1-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 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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 to MNRAS; 26 pages, 13 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/2101.03843">arXiv:2101.03843</a> <span> [<a href="https://arxiv.org/pdf/2101.03843">pdf</a>, <a href="https://arxiv.org/format/2101.03843">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> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">stat.ML</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/stab028">10.1093/mnras/stab028 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evolutionary Map of the Universe (EMU):Compact radio sources in the SCORPIO field towards the Galactic plane </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Hopkins%2C+A+M">A. M. Hopkins</a>, <a href="/search/astro-ph?searchtype=author&query=Filipovi%C4%87%2C+M+D">M. D. Filipovi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Andernach%2C+H">H. Andernach</a>, <a href="/search/astro-ph?searchtype=author&query=van+Loon%2C+J+T">J. Th. van Loon</a>, <a href="/search/astro-ph?searchtype=author&query=Micha%C5%82owski%2C+M+J">M. J. Micha艂owski</a>, <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=An%2C+T">T. An</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Carretti%2C+E">E. Carretti</a>, <a href="/search/astro-ph?searchtype=author&query=Collier%2C+J+D">J. D. Collier</a>, <a href="/search/astro-ph?searchtype=author&query=Joseph%2C+T">T. Joseph</a>, <a href="/search/astro-ph?searchtype=author&query=Koribalski%2C+B+S">B. S. Koribalski</a>, <a href="/search/astro-ph?searchtype=author&query=Kothes%2C+R">R. Kothes</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=McConnell%2C+D">D. McConnell</a>, <a href="/search/astro-ph?searchtype=author&query=Pommier%2C+M">M. Pommier</a>, <a href="/search/astro-ph?searchtype=author&query=Sciacca%2C+E">E. Sciacca</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.03843v1-abstract-short" style="display: inline;"> We present observations of a region of the Galactic plane taken during the Early Science Program of the Australian Square Kilometre Array Pathfinder (ASKAP). In this context, we observed the SCORPIO field at 912 MHz with an uncompleted array consisting of 15 commissioned antennas. The resulting map covers a square region of ~40 deg^2, centred on (l, b)=(343.5掳, 0.75掳), with a synthesized beam of 2… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.03843v1-abstract-full').style.display = 'inline'; document.getElementById('2101.03843v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.03843v1-abstract-full" style="display: none;"> We present observations of a region of the Galactic plane taken during the Early Science Program of the Australian Square Kilometre Array Pathfinder (ASKAP). In this context, we observed the SCORPIO field at 912 MHz with an uncompleted array consisting of 15 commissioned antennas. The resulting map covers a square region of ~40 deg^2, centred on (l, b)=(343.5掳, 0.75掳), with a synthesized beam of 24"x21" and a background rms noise of 150-200 渭Jy/beam, increasing to 500-600 渭Jy/beam close to the Galactic plane. A total of 3963 radio sources were detected and characterized in the field using the CAESAR source finder. We obtained differential source counts in agreement with previously published data after correction for source extraction and characterization uncertainties, estimated from simulated data. The ASKAP positional and flux density scale accuracy were also investigated through comparison with previous surveys (MGPS, NVSS) and additional observations of the SCORPIO field, carried out with ATCA at 2.1 GHz and 10" spatial resolution. These allowed us to obtain a measurement of the spectral index for a subset of the catalogued sources and an estimated fraction of (at least) 8% of resolved sources in the reported catalogue. We cross-matched our catalogued sources with different astronomical databases to search for possible counterparts, finding ~150 associations to known Galactic objects. Finally, we explored a multiparametric approach for classifying previously unreported Galactic sources based on their radio-infrared colors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.03843v1-abstract-full').style.display = 'none'; document.getElementById('2101.03843v1-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 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">31 pages, 15 figures, 15 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/2012.02116">arXiv:2012.02116</a> <span> [<a href="https://arxiv.org/pdf/2012.02116">pdf</a>, <a href="https://arxiv.org/format/2012.02116">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> </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/10.1051/0004-6361/202039052">10.1051/0004-6361/202039052 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Monitoring the radio emission of Proxima Centauri </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=P%C3%A9rez-Torres%2C+M">Miguel P茅rez-Torres</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B3mez%2C+J+F">Jos茅 Francisco G贸mez</a>, <a href="/search/astro-ph?searchtype=author&query=Ortiz%2C+J+L">Jos茅 Luis Ortiz</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Anglada%2C+G">Guillem Anglada</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B3mez%2C+J+L">Jos茅 Luis G贸mez</a>, <a href="/search/astro-ph?searchtype=author&query=Rodr%C3%ADguez%2C+E">Eloy Rodr铆guez</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">Corrado Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Amado%2C+P+J">Pedro J. Amado</a>, <a href="/search/astro-ph?searchtype=author&query=Alberdi%2C+A">Antonio Alberdi</a>, <a href="/search/astro-ph?searchtype=author&query=Anglada-Escud%C3%A9%2C+G">Guillem Anglada-Escud茅</a>, <a href="/search/astro-ph?searchtype=author&query=Osorio%2C+M">Mayra Osorio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">Grazia Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Berdi%C3%B1as%2C+Z">Zaira Berdi帽as</a>, <a href="/search/astro-ph?searchtype=author&query=L%C3%B3pez-Gonz%C3%A1lez%2C+M+J">Mar铆a Jos茅 L贸pez-Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Morales%2C+N">Nicol谩s Morales</a>, <a href="/search/astro-ph?searchtype=author&query=Rodr%C3%ADguez-L%C3%B3pez%2C+C">Cristina Rodr铆guez-L贸pez</a>, <a href="/search/astro-ph?searchtype=author&query=Chibueze%2C+J">James Chibueze</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="2012.02116v2-abstract-short" style="display: inline;"> We present results from the most comprehensive radio monitoring campaign towards the closest star to our Sun, Proxima Centauri. We report 1.1 to 3.1 GHz observations with the Australian Telescope Compact Array over 18 consecutive days in April 2017. We detect radio emission from Proxima Centauri for most of the observing sessions, which spanned $\sim$1.6 orbital periods of the planet Proxima b. Th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.02116v2-abstract-full').style.display = 'inline'; document.getElementById('2012.02116v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.02116v2-abstract-full" style="display: none;"> We present results from the most comprehensive radio monitoring campaign towards the closest star to our Sun, Proxima Centauri. We report 1.1 to 3.1 GHz observations with the Australian Telescope Compact Array over 18 consecutive days in April 2017. We detect radio emission from Proxima Centauri for most of the observing sessions, which spanned $\sim$1.6 orbital periods of the planet Proxima b. The radio emission is stronger at the low-frequency band, centered around 1.6 GHz, and is consistent with the expected electron-cyclotron frequency for the known star's magnetic field intensity of about 600 Gauss. The 1.6 GHz light curve shows an emission pattern that is consistent with the orbital period of the planet Proxima b around the star Proxima, with its maxima of emission happening near the quadratures. We also observed two short-duration (a few minutes) flares and a long-duration (about three days) burst whose peaks happened close to the quadratures. We find that the frequency, large degree of circular polarization, change of the sign of circular polarization, and intensity of the observed radio emission are all consistent with expectations from electron cyclotron-maser emission arising from sub-Alfv茅nic star-planet interaction. We interpret our radio observations as signatures of interaction between the planet Proxima b and its host star Proxima. We advocate for monitoring other dwarf stars with planets to eventually reveal periodic radio emission due to star-planet interaction, thus opening a new avenue for exoplanet hunting and the study of a new field of exoplanet-star plasma interaction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.02116v2-abstract-full').style.display = 'none'; document.getElementById('2012.02116v2-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 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 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">14 pages, 11 figures. Accepted on December 2, 2020 in A&A (main journal), several typos corrected</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 645, A77 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2011.08161">arXiv:2011.08161</a> <span> [<a href="https://arxiv.org/pdf/2011.08161">pdf</a>, <a href="https://arxiv.org/format/2011.08161">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/staa3606">10.1093/mnras/staa3606 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A warm molecular ring in AG Car: composing the mass-loss puzzle </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bordiu%2C+C">C. Bordiu</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Rizzo%2C+J+R">J. R. Rizzo</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</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="2011.08161v1-abstract-short" style="display: inline;"> We present APEX observations of CO J=3-2 and ALMA observations of CO J=2-1, 13CO J=2-1 and continuum toward the galactic luminous blue variable AG Car. These new observations reveal the presence of a ring-like molecular structure surrounding the star. Morphology and kinematics of the gas are consistent with a slowly expanding torus located near the equatorial plane of AG Car. Using non-LTE line mo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.08161v1-abstract-full').style.display = 'inline'; document.getElementById('2011.08161v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2011.08161v1-abstract-full" style="display: none;"> We present APEX observations of CO J=3-2 and ALMA observations of CO J=2-1, 13CO J=2-1 and continuum toward the galactic luminous blue variable AG Car. These new observations reveal the presence of a ring-like molecular structure surrounding the star. Morphology and kinematics of the gas are consistent with a slowly expanding torus located near the equatorial plane of AG Car. Using non-LTE line modelling, we derived the physical parameters of the gas, which is warm (50 K) and moderately dense (10$^3$ cm$^{-3}$. The total mass of molecular gas in the ring is 2.7$\pm$0.9 solar masses. We analysed the radio continuum map, which depicts a point-like source surrounded by a shallow nebula. From the flux of the point-like source, we derived a current mass-loss date of $1.55\pm0.21\times10^{-5}$ solar masses / yr. Finally, to better understand the complex circumstellar environment of AG Car, we put the newly detected ring in relation to the main nebula of dust and ionised gas. We discuss possible formation scenarios for the ring, namely, the accumulation of interstellar material due to the action of the stellar wind, the remnant of a close binary interaction or merger, and an equatorially enhanced mass-loss episode. If molecular gas formed in situ as a result of a mass eruption, it would account for at least a 30$\%$ of the total mass ejected by AG Car. This detection adds a new piece to the puzzle of the complex mass-loss history of AG Car, providing new clues about the interplay between LBV stars and their surroundings. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.08161v1-abstract-full').style.display = 'none'; document.getElementById('2011.08161v1-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 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">16 pages, 13 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/2009.09948">arXiv:2009.09948</a> <span> [<a href="https://arxiv.org/pdf/2009.09948">pdf</a>, <a href="https://arxiv.org/format/2009.09948">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </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/staa2868">10.1093/mnras/staa2868 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New high-frequency radio observations of the Cygnus Loop supernova remnant with the Italian radio telescopes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Pellizzoni%2C+A">A. Pellizzoni</a>, <a href="/search/astro-ph?searchtype=author&query=Egron%2C+E">E. Egron</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Morlino%2C+G">G. Morlino</a>, <a href="/search/astro-ph?searchtype=author&query=Celli%2C+S">S. Celli</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Iacolina%2C+M+N">M. N. Iacolina</a>, <a href="/search/astro-ph?searchtype=author&query=Righini%2C+S">S. Righini</a>, <a href="/search/astro-ph?searchtype=author&query=Reich%2C+P">P. Reich</a>, <a href="/search/astro-ph?searchtype=author&query=Mulas%2C+S">S. Mulas</a>, <a href="/search/astro-ph?searchtype=author&query=Marongiu%2C+M">M. Marongiu</a>, <a href="/search/astro-ph?searchtype=author&query=Pilia%2C+M">M. Pilia</a>, <a href="/search/astro-ph?searchtype=author&query=Melis%2C+A">A. Melis</a>, <a href="/search/astro-ph?searchtype=author&query=Concu%2C+R">R. Concu</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+M">M. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Schillir%C3%B2%2C+F">F. Schillir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="2009.09948v1-abstract-short" style="display: inline;"> Supernova remnants (SNRs) represent a powerful laboratory to study the Cosmic-Ray acceleration processes at the shocks, and their relation to the properties of the circumstellar medium. With the aim of studying the high-frequency radio emission and investigating the energy distribution of accelerated electrons and the magnetic field conditions, we performed single-dish observations of the large an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.09948v1-abstract-full').style.display = 'inline'; document.getElementById('2009.09948v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.09948v1-abstract-full" style="display: none;"> Supernova remnants (SNRs) represent a powerful laboratory to study the Cosmic-Ray acceleration processes at the shocks, and their relation to the properties of the circumstellar medium. With the aim of studying the high-frequency radio emission and investigating the energy distribution of accelerated electrons and the magnetic field conditions, we performed single-dish observations of the large and complex Cygnus Loop SNR from 7.0 to 24.8 GHz with the Medicina and the Sardinia Radio Telescope, focusing on the northern filament (NGC 6992) and the southern shell. Both regions show a spectrum well fitted by a power-law function ($S\propto谓^{-伪}$), with spectral index $伪=0.45\pm0.05$ for NGC 6992 and $伪=0.49\pm0.01$ for the southern shell and without any indication of a spectral break. The spectra are significantly flatter than the whole Cygnus Loop spectrum ($伪=0.54\pm0.01$), suggesting a departure from the plain shock acceleration mechanisms, which for NGC 6992 could be related to the ongoing transition towards a radiative shock. We model the integrated spectrum of the whole SNR considering the evolution of the maximum energy and magnetic field amplification. Through the radio spectral parameters, we infer a magnetic field at the shock of 10 $渭$G. This value is compatible with a pure adiabatic compression of the interstellar magnetic field, suggesting that the amplification process is currently inefficient. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.09948v1-abstract-full').style.display = 'none'; document.getElementById('2009.09948v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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, 13 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/2009.02363">arXiv:2009.02363</a> <span> [<a href="https://arxiv.org/pdf/2009.02363">pdf</a>, <a href="https://arxiv.org/ps/2009.02363">ps</a>, <a href="https://arxiv.org/format/2009.02363">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnrasl/slaa157">10.1093/mnrasl/slaa157 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The auroral radio emission of the magnetic B-type star rho OphC </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</a>, <a href="/search/astro-ph?searchtype=author&query=Pillitteri%2C+I">I. Pillitteri</a>, <a href="/search/astro-ph?searchtype=author&query=Fossati%2C+L">L. Fossati</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Krticka%2C+J">J. Krticka</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Catanzaro%2C+G">G. Catanzaro</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Schilliro%2C+F">F. Schilliro</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Giarrusso%2C+M">M. Giarrusso</a>, <a href="/search/astro-ph?searchtype=author&query=Robrade%2C+J">J. Robrade</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="2009.02363v1-abstract-short" style="display: inline;"> The non-thermal radio emission of main-sequence early-type stars is a signature of stellar magnetism. We present multi-wavelength (1.6-16.7 GHz) ATCA measurements of the early-type magnetic star rho OphC, which is a flat-spectrum non-thermal radio source. The rho OphC radio emission is partially circularly polarized with a steep spectral dependence: the fraction of polarized emission is about 60%… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.02363v1-abstract-full').style.display = 'inline'; document.getElementById('2009.02363v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.02363v1-abstract-full" style="display: none;"> The non-thermal radio emission of main-sequence early-type stars is a signature of stellar magnetism. We present multi-wavelength (1.6-16.7 GHz) ATCA measurements of the early-type magnetic star rho OphC, which is a flat-spectrum non-thermal radio source. The rho OphC radio emission is partially circularly polarized with a steep spectral dependence: the fraction of polarized emission is about 60% at the lowest frequency sub-band (1.6 GHz) while is undetected at 16.7 GHz. This is clear evidence of coherent Auroral Radio Emission (ARE) from the rho OphC magnetosphere. Interestingly, the detection of the rho OphC's ARE is not related to a peculiar rotational phase. This is a consequence of the stellar geometry, which makes the strongly anisotropic radiation beam of the amplified radiation always pointed towards Earth. The circular polarization sign evidences mainly amplification of the ordinary mode of the electromagnetic wave, consistent with a maser amplification occurring within dense regions. This is indirect evidence of the plasma evaporation from the polar caps, a phenomenon responsible for the thermal X-ray aurorae. rho OphC is not the first early-type magnetic star showing the O-mode dominated ARE but is the first star with the ARE always on view. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.02363v1-abstract-full').style.display = 'none'; document.getElementById('2009.02363v1-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, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">5 pages, 4 figures; accepted to MNRAS Letter</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.11591">arXiv:2007.11591</a> <span> [<a href="https://arxiv.org/pdf/2007.11591">pdf</a>, <a href="https://arxiv.org/ps/2007.11591">ps</a>, <a href="https://arxiv.org/format/2007.11591">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202038214">10.1051/0004-6361/202038214 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Chandra's X-ray study confirms that the magnetic standard Ap star KQ Vel hosts a neutron star companion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">Lidia M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">Richard Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Postnov%2C+K+A">Konstantin A. Postnov</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="2007.11591v1-abstract-short" style="display: inline;"> KQ Vel is a peculiar A0p star with a strong surface magnetic field of about 7.5 kG. It has a slow rotational period of nearly 8 years. Bailey et al. (2015) detected a binary companion of uncertain nature, and suggested it could be a neutron star or a black hole. In this Letter we analyze X-ray data obtained by the Chandra telescope to ascertain information about the stellar magnetic field and inte… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.11591v1-abstract-full').style.display = 'inline'; document.getElementById('2007.11591v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.11591v1-abstract-full" style="display: none;"> KQ Vel is a peculiar A0p star with a strong surface magnetic field of about 7.5 kG. It has a slow rotational period of nearly 8 years. Bailey et al. (2015) detected a binary companion of uncertain nature, and suggested it could be a neutron star or a black hole. In this Letter we analyze X-ray data obtained by the Chandra telescope to ascertain information about the stellar magnetic field and interaction between the star and its companion. We confirm previous X-ray detection of KQ Vel with a relatively large X-ray luminosity of 2\times 10^{30} erg/s. X-ray spectra suggest the presence of hot gas at > 20MK and, possibly, of a non-thermal component. X-ray light curves are variable, but better quality data are needed to determine periodicity if any. We interpret X-ray spectra as a combination of two components: the non-thermal emission arising from the aurora on the A0p star and the hot thermal plasma filling the extended shell surrounding the "propelling" neutron star. We explore various alternatives, but a hybrid model involving the stellar magnetosphere along with a hot shell around the propelling neutron star seems most plausible. We speculate that KQ Vel was originally a triple system, and the Ap star is a merger product. We conclude that KQ Vel is an intermediate-mass binary consisting of a strongly magnetic main sequence star and a neutron star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.11591v1-abstract-full').style.display = 'none'; document.getElementById('2007.11591v1-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 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">accepted to A&AL. 8 pages including the appendix where the formalism describing the X-ray emission from a hot shell around a propelling neutron star in settling accretion regime is presented</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 641, L8 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2002.09251">arXiv:2002.09251</a> <span> [<a href="https://arxiv.org/pdf/2002.09251">pdf</a>, <a href="https://arxiv.org/ps/2002.09251">ps</a>, <a href="https://arxiv.org/format/2002.09251">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/staa587">10.1093/mnras/staa587 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evidence for radio and X-ray auroral emissions from the magnetic B-type star rho Oph A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</a>, <a href="/search/astro-ph?searchtype=author&query=Pillitteri%2C+I">I. Pillitteri</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Fossati%2C+L">L. Fossati</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Krticka%2C+J">J. Krticka</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Catanzaro%2C+G">G. Catanzaro</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Munari%2C+M">M. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Gangi%2C+M">M. Gangi</a>, <a href="/search/astro-ph?searchtype=author&query=Giarrusso%2C+M">M. Giarrusso</a>, <a href="/search/astro-ph?searchtype=author&query=Robrade%2C+J">J. Robrade</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="2002.09251v2-abstract-short" style="display: inline;"> We present new ATCA multi-wavelength radio measurements (range 2.1-21.2 GHz) of the early-type magnetic star rho Oph A, performed in March 2019 during 3 different observing sessions. These new ATCA observations evidence a clear rotational modulation of the stellar radio emission and the detection of coherent auroral radio emission from rho Oph A at 2.1 GHz. We collected high-resolution optical spe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.09251v2-abstract-full').style.display = 'inline'; document.getElementById('2002.09251v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.09251v2-abstract-full" style="display: none;"> We present new ATCA multi-wavelength radio measurements (range 2.1-21.2 GHz) of the early-type magnetic star rho Oph A, performed in March 2019 during 3 different observing sessions. These new ATCA observations evidence a clear rotational modulation of the stellar radio emission and the detection of coherent auroral radio emission from rho Oph A at 2.1 GHz. We collected high-resolution optical spectra of rho Oph A acquired by several instruments over a time span of about ten years. We also report new magnetic field measurements of rho Oph A that, together with the radio light curves and the temporal variation of the equivalent width of the HeI line (lambda=5015 Angstrom), were used to constrain the rotation period and the stellar magnetic field geometry. The above results have been used to model the stellar radio emission, modelling that allowed us to constrain the physical condition of rho Oph A's magnetosphere. Past XMM measurements showed periodic X-ray pulses from rho Oph A. We correlate the X-ray light curve with the magnetic field geometry of rho Oph A. The already published XMM data have been re-analyzed showing that the X-ray spectra of rho Oph A are compatible with the presence of a non-thermal X-ray component. We discuss a scenario where the emission phenomena occurring at the extremes of the electromagnetic spectrum, radio and X-ray, are directly induced by the same plasma process. We interpret the observed X-ray and radio features of rho Oph A as having an auroral origin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.09251v2-abstract-full').style.display = 'none'; document.getElementById('2002.09251v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 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">20 pages, 13 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/1910.11592">arXiv:1910.11592</a> <span> [<a href="https://arxiv.org/pdf/1910.11592">pdf</a>, <a href="https://arxiv.org/format/1910.11592">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/stz2982">10.1093/mnras/stz2982 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Study of the Galactic radio sources in the SCORPIO survey resolved by ATCA at 2.1 GHz </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Franzen%2C+T+M+O">T. M. O. Franzen</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Schillir%C3%B2%2C+F">F. Schillir貌</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</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="1910.11592v1-abstract-short" style="display: inline;"> We present a catalogue of a large sample of extended radio sources in the SCORPIO field, observed and resolved by the Australia Telescope Compact Array. SCORPIO, a pathfinder project for addressing the early operations of the Australia SKA Pathfinder, is a survey of ~5 square degrees between 1.4 and 3.1 GHz, centered at l=343.5掳, b=0.75掳 and with an angular resolution of about 10 arcsec. It is aim… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.11592v1-abstract-full').style.display = 'inline'; document.getElementById('1910.11592v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.11592v1-abstract-full" style="display: none;"> We present a catalogue of a large sample of extended radio sources in the SCORPIO field, observed and resolved by the Australia Telescope Compact Array. SCORPIO, a pathfinder project for addressing the early operations of the Australia SKA Pathfinder, is a survey of ~5 square degrees between 1.4 and 3.1 GHz, centered at l=343.5掳, b=0.75掳 and with an angular resolution of about 10 arcsec. It is aimed at understanding the scientific and technical challenges to be faced by future Galactic surveys. With a mean sensitivity around 100 $渭$Jy/beam and the possibility to recover angular scales at least up to 4 arcmin, we extracted 99 extended sources, 35 of them detected for the first time. Among the 64 known sources 55 had at least a tentative classification in literature. Studying the radio morphology and comparing the radio emission with infrared we propose as candidates 6 new H II regions, 2 new planetary nebulae, 2 new luminous blue variable or Wolf--Rayet stars and 3 new supernova remnants. This study provides an overview of the potentiality of future radio surveys in terms of Galactic source extraction and characterization and a discussion on the difficulty to reduce and analyze interferometric data on the Galactic plane. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.11592v1-abstract-full').style.display = 'none'; document.getElementById('1910.11592v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1909.06116">arXiv:1909.06116</a> <span> [<a href="https://arxiv.org/pdf/1909.06116">pdf</a>, <a href="https://arxiv.org/format/1909.06116">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="Computation">stat.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">stat.ML</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1017/pasa.2019.29">10.1017/pasa.2019.29 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> CAESAR source finder: recent developments and testing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Vitello%2C+F">F. Vitello</a>, <a href="/search/astro-ph?searchtype=author&query=Becciani%2C+U">U. Becciani</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Calanducci%2C+A">A. Calanducci</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Costa%2C+A">A. Costa</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Schillir%C3%B2%2C+F">F. Schillir貌</a>, <a href="/search/astro-ph?searchtype=author&query=Sciacca%2C+E">E. Sciacca</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</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="1909.06116v1-abstract-short" style="display: inline;"> A new era in radioastronomy will begin with the upcoming large-scale surveys planned at the Australian Square Kilometre Array Pathfinder (ASKAP). ASKAP started its Early Science program in October 2017 and several target fields were observed during the array commissioning phase. The SCORPIO field was the first observed in the Galactic Plane in Band 1 (792-1032 MHz) using 15 commissioned antennas.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.06116v1-abstract-full').style.display = 'inline'; document.getElementById('1909.06116v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1909.06116v1-abstract-full" style="display: none;"> A new era in radioastronomy will begin with the upcoming large-scale surveys planned at the Australian Square Kilometre Array Pathfinder (ASKAP). ASKAP started its Early Science program in October 2017 and several target fields were observed during the array commissioning phase. The SCORPIO field was the first observed in the Galactic Plane in Band 1 (792-1032 MHz) using 15 commissioned antennas. The achieved sensitivity and large field of view already allow to discover new sources and survey thousands of existing ones with improved precision with respect to previous surveys. Data analysis is currently ongoing to deliver the first source catalogue. Given the increased scale of the data, source extraction and characterization, even in this Early Science phase, have to be carried out in a mostly automated way. This process presents significant challenges due to the presence of extended objects and diffuse emission close to the Galactic Plane. In this context we have extended and optimized a novel source finding tool, named CAESAR , to allow extraction of both compact and extended sources from radio maps. A number of developments have been done driven by the analysis of the SCORPIO map and in view of the future ASKAP Galactic Plane survey. The main goals are the improvement of algorithm performances and scalability as well as of software maintainability and usability within the radio community. In this paper we present the current status of CAESAR and report a first systematic characterization of its performance for both compact and extended sources using simulated maps. Future prospects are discussed in light of the obtained results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.06116v1-abstract-full').style.display = 'none'; document.getElementById('1909.06116v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">15 pages, 10 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Publications of the Astronomical Society of Australia, 2019, 36, E037 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.08013">arXiv:1904.08013</a> <span> [<a href="https://arxiv.org/pdf/1904.08013">pdf</a>, <a href="https://arxiv.org/ps/1904.08013">ps</a>, <a href="https://arxiv.org/format/1904.08013">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201935239">10.1051/0004-6361/201935239 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A massive nebula around the Luminous Blue Variable star RMC143 revealed by ALMA </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">Claudia Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Mehner%2C+A">Andrea Mehner</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">Neil Matthew Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Groh%2C+J">Jose Groh</a>, <a href="/search/astro-ph?searchtype=author&query=Noriega-Crespo%2C+A">Alberto Noriega-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">Carla Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">Francesco Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">Luciano Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">Adriano Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Paladini%2C+R">Roberta Paladini</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">Giuliano Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">Corrado Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">Grazia Umana</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="1904.08013v2-abstract-short" style="display: inline;"> The luminous blue variable (LBV) RMC143 is located in the outskirts of the 30~Doradus complex, a region rich with interstellar material and hot luminous stars. We report the $3蟽$ sub-millimetre detection of its circumstellar nebula with ALMA. The observed morphology in the sub-millimetre is different than previously observed with HST and ATCA in the optical and centimetre wavelength regimes. The s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.08013v2-abstract-full').style.display = 'inline'; document.getElementById('1904.08013v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.08013v2-abstract-full" style="display: none;"> The luminous blue variable (LBV) RMC143 is located in the outskirts of the 30~Doradus complex, a region rich with interstellar material and hot luminous stars. We report the $3蟽$ sub-millimetre detection of its circumstellar nebula with ALMA. The observed morphology in the sub-millimetre is different than previously observed with HST and ATCA in the optical and centimetre wavelength regimes. The spectral energy distribution (SED) of RMC143 suggests that two emission mechanisms contribute to the sub-mm emission: optically thin bremsstrahlung and dust. Both the extinction map and the SED are consistent with a dusty massive nebula with a dust mass of $0.055\pm0.018~M_{\odot}$ (assuming $魏_{850}=1.7\rm\,cm^{2}\,g^{-1}$). To date, RMC143 has the most dusty LBV nebula observed in the Magellanic Clouds. We have also re-examined the LBV classification of RMC143 based on VLT/X-shooter spectra obtained in 2015/16 and a review of the publication record. The radiative transfer code CMFGEN is used to derive its fundamental stellar parameters. We find an effective temperature of $\sim 8500$~K, luminosity of log$(L/L_{\odot}) = 5.32$, and a relatively high mass-loss rate of $1.0 \times 10^{-5}~M_{\odot}$~yr$^{-1}$. The luminosity is much lower than previously thought, which implies that the current stellar mass of $\sim8~M_{\odot}$ is comparable to its nebular mass of $\sim 5.5~M_{\odot}$ (from an assumed gas-to-dust ratio of 100), suggesting that the star has lost a large fraction of its initial mass in past LBV eruptions or binary interactions. While the star may have been hotter in the past, it is currently not hot enough to ionize its circumstellar nebula. We propose that the nebula is ionized externally by the hot stars in the 30~Doradus star-forming region. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.08013v2-abstract-full').style.display = 'none'; document.getElementById('1904.08013v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">Paper accepted by A&A on 09/05/2019 and in proof stage. Second comments by referee are included in this version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 626, A126 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1903.07331">arXiv:1903.07331</a> <span> [<a href="https://arxiv.org/pdf/1903.07331">pdf</a>, <a href="https://arxiv.org/ps/1903.07331">ps</a>, <a href="https://arxiv.org/format/1903.07331">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/10.1051/0004-6361/201834937">10.1051/0004-6361/201834937 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> HST/STIS analysis of the first main sequence pulsar CU Vir </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Krticka%2C+J">J. Krticka</a>, <a href="/search/astro-ph?searchtype=author&query=Mikulasek%2C+Z">Z. Mikulasek</a>, <a href="/search/astro-ph?searchtype=author&query=Henry%2C+G+W">G. W. Henry</a>, <a href="/search/astro-ph?searchtype=author&query=Janik%2C+J">J. Janik</a>, <a href="/search/astro-ph?searchtype=author&query=Kochukhov%2C+O">O. Kochukhov</a>, <a href="/search/astro-ph?searchtype=author&query=Pigulski%2C+A">A. Pigulski</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Krtickova%2C+I">I. Krtickova</a>, <a href="/search/astro-ph?searchtype=author&query=Luftinger%2C+T">T. Luftinger</a>, <a href="/search/astro-ph?searchtype=author&query=Prvak%2C+M">M. Prvak</a>, <a href="/search/astro-ph?searchtype=author&query=Tichy%2C+A">A. Tichy</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="1903.07331v1-abstract-short" style="display: inline;"> CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period. We study the ultraviolet (UV) spectrum of CU Vir obtained using STIS spec… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.07331v1-abstract-full').style.display = 'inline'; document.getElementById('1903.07331v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.07331v1-abstract-full" style="display: none;"> CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period. We study the ultraviolet (UV) spectrum of CU Vir obtained using STIS spectrograph onboard the Hubble Space Telescope (HST) to search for the source of radio emission and to test the model of the rotational period evolution. We used our own far-UV and visual photometric observations supplemented with the archival data to improve the parameters of the quasisinusoidal long-term variations of the rotational period. We predict the flux variations of CU Vir from surface abundance maps and compare these variations with UV flux distribution. We searched for wind, auroral, and interstellar lines in the spectra. The UV and visual light curves display the same long-term period variations supporting their common origin. New updated abundance maps provide better agreement with the observed flux distribution. The upper limit of the wind mass-loss rate is about $10^{-12}\,M_\odot\,\rm{yr}^{-1}$. We do not find any auroral lines. We find rotationally modulated variability of interstellar lines, which is most likely of instrumental origin. Our analysis supports the flux redistribution from far-UV to near-UV and visual domains originating in surface abundance spots as the main cause of the flux variability in chemically peculiar stars. Therefore, UV and optical variations are related and the structures leading to these variations are rigidly confined to the stellar surface. The radio emission of CU Vir is most likely powered by a very weak presumably purely metallic wind, which leaves no imprint in spectra. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.07331v1-abstract-full').style.display = 'none'; document.getElementById('1903.07331v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">12 pages, accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 625, A34 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1809.07504">arXiv:1809.07504</a> <span> [<a href="https://arxiv.org/pdf/1809.07504">pdf</a>, <a href="https://arxiv.org/ps/1809.07504">ps</a>, <a href="https://arxiv.org/format/1809.07504">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnrasl/sly179">10.1093/mnrasl/sly179 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The polarization mode of the auroral radio emission from the early-type star HD142301 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Todt%2C+H">H. Todt</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</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="1809.07504v1-abstract-short" style="display: inline;"> We report the detection of the auroral radio emission from the early-type magnetic star HD142301. New VLA observations of HD142301 detected highly polarized amplified emission occurring at fixed stellar orientations. The coherent emission mechanism responsible for the stellar auroral radio emission amplifies the radiation within a narrow beam, making the star where this phenomenon occurs similar t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.07504v1-abstract-full').style.display = 'inline'; document.getElementById('1809.07504v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.07504v1-abstract-full" style="display: none;"> We report the detection of the auroral radio emission from the early-type magnetic star HD142301. New VLA observations of HD142301 detected highly polarized amplified emission occurring at fixed stellar orientations. The coherent emission mechanism responsible for the stellar auroral radio emission amplifies the radiation within a narrow beam, making the star where this phenomenon occurs similar to a radio lighthouse. The elementary emission process responsible for the auroral radiation mainly amplifies one of the two magneto-ionic modes of the electromagnetic wave. This explains why the auroral pulses are highly circularly polarized. The auroral radio emission of HD142301 is characterized by a reversal of the sense of polarization as the star rotates. The effective magnetic field curve of HD142301 is also available making it possible to correlate the transition from the left to the right-hand circular polarization sense (and vice-versa) of the auroral pulses with the known orientation of the stellar magnetic field. The results presented in this letter have implications for the estimation of the dominant magneto-ionic mode amplified within the HD142301 magnetosphere. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.07504v1-abstract-full').style.display = 'none'; document.getElementById('1809.07504v1-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, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2018. </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">5 pages, 4 figures; accepted to MNRAS 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/1808.02367">arXiv:1808.02367</a> <span> [<a href="https://arxiv.org/pdf/1808.02367">pdf</a>, <a href="https://arxiv.org/format/1808.02367">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201833492">10.1051/0004-6361/201833492 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Outstanding X-ray emission from the stellar radio pulsar CU Virginis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Robrade%2C+J">J. Robrade</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Schmitt%2C+J+H+M+M">J. H. M. M. Schmitt</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</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="1808.02367v1-abstract-short" style="display: inline;"> We present X-ray observations of CU Vir performed with XMM-Newton and Chandra. With Lx = 3 x 10^28 erg/s the source is moderately X-ray bright, but its spectrum is extremely hard compared to other Ap stars. Spectral modelling requires multi-component models with predominant hot plasma at temperatures of about Tx = 25 MK or, alternatively, a nonthermal spectral component. The Chandra observations w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1808.02367v1-abstract-full').style.display = 'inline'; document.getElementById('1808.02367v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1808.02367v1-abstract-full" style="display: none;"> We present X-ray observations of CU Vir performed with XMM-Newton and Chandra. With Lx = 3 x 10^28 erg/s the source is moderately X-ray bright, but its spectrum is extremely hard compared to other Ap stars. Spectral modelling requires multi-component models with predominant hot plasma at temperatures of about Tx = 25 MK or, alternatively, a nonthermal spectral component. The Chandra observations was performed six years later than the one by XMM-Newton, yet the source has similar X-ray flux and spectrum, suggesting a steady and persistent X-ray emission. To explain its full X-ray properties, a generating mechanism beyond standard explanations like the presence of a low-mass companion or magnetically confined wind-shocks is required. Magnetospheric activity might be present or, as proposed for fast rotating strongly magnetic Bp stars, the X-ray emission of CU Vir is predominantly auroral in nature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1808.02367v1-abstract-full').style.display = 'none'; document.getElementById('1808.02367v1-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 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2018. </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</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1803.08338">arXiv:1803.08338</a> <span> [<a href="https://arxiv.org/pdf/1803.08338">pdf</a>, <a href="https://arxiv.org/format/1803.08338">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/sty2280">10.1093/mnras/sty2280 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detection of Alpha Centauri at radio wavelengths: chromospheric emission and search for star-planet interaction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</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="1803.08338v2-abstract-short" style="display: inline;"> At radio wavelengths, solar-type stars emit thermal free-free and gyroresonance, gyrosynchrotron, and impulsive coherent emission. Thermal free-free emission originates at layers where the optical depth is close to unit, while high brightness temperature, variable emission, can be due to flares via gyrosynchrotron emission. We observed the alpha Cen system with the Australian Telescope Compact Arr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1803.08338v2-abstract-full').style.display = 'inline'; document.getElementById('1803.08338v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1803.08338v2-abstract-full" style="display: none;"> At radio wavelengths, solar-type stars emit thermal free-free and gyroresonance, gyrosynchrotron, and impulsive coherent emission. Thermal free-free emission originates at layers where the optical depth is close to unit, while high brightness temperature, variable emission, can be due to flares via gyrosynchrotron emission. We observed the alpha Cen system with the Australian Telescope Compact Array at 2 GHz for three days and 17 GHz for one day. Both stars have been detected at 17 GHz, while only an upper limit has been obtained at low frequency despite the longer integration time. The brightness temperatures are consistent with the temperature of the upper chromosphere of the Sun. Inverting the formulae of the free-free emission, the average electron density of the plasma has been inferred. The same procedure was applied to the data in the millimetre recently acquired with ALMA. A comparison with the atmospheric solar models reveals a higher level of activity in alpha Cen B rather than in alpha Cen A, even if still at quiescent level. The non detection at 2 GHz allows us to put a lower limit in the filling factor of active regions. The claimed detection of an Earth size planet in close orbit to alpha Cen B, although doubtful, opens the opportunity to check the existence of Star-Planet Magnetic Interaction (SPMI). We constructed dynamic spectra in the 1.3 - 2.9 GHz of the 2 stars to search for time-variable coherent emission but obtained a null result. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1803.08338v2-abstract-full').style.display = 'none'; document.getElementById('1803.08338v2-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 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 March, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2018. </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, 9 pages, 7 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/1801.08738">arXiv:1801.08738</a> <span> [<a href="https://arxiv.org/pdf/1801.08738">pdf</a>, <a href="https://arxiv.org/ps/1801.08738">ps</a>, <a href="https://arxiv.org/format/1801.08738">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/sty244">10.1093/mnras/sty244 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A combined multiwavelength VLA/ALMA/Chandra study unveils the complex magnetosphere of the B-type star HR5907 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L+M">L. M. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Todt%2C+H">H. Todt</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</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="1801.08738v1-abstract-short" style="display: inline;"> We present new radio/millimeter measurements of the hot magnetic star HR5907 obtained with the VLA and ALMA interferometers. We find that HR5907 is the most radio luminous early type star in the cm-mm band among those presently known. Its multi-wavelength radio light curves are strongly variable with an amplitude that increases with radio frequency. The radio emission can be explained by the popul… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.08738v1-abstract-full').style.display = 'inline'; document.getElementById('1801.08738v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.08738v1-abstract-full" style="display: none;"> We present new radio/millimeter measurements of the hot magnetic star HR5907 obtained with the VLA and ALMA interferometers. We find that HR5907 is the most radio luminous early type star in the cm-mm band among those presently known. Its multi-wavelength radio light curves are strongly variable with an amplitude that increases with radio frequency. The radio emission can be explained by the populations of the non-thermal electrons accelerated in the current sheets on the outer border of the magnetosphere of this fast rotating magnetic star. We classify HR5907 as another member of the growing class of strongly magnetic fast rotating hot stars where the gyro-synchrotron emission mechanism efficiently operates in their magnetospheres. The new radio observations of HR5907 are combined with archival X-ray data to study the physical condition of its magnetosphere. The X-ray spectra of HR5907 show tentative evidence for the presence of non-thermal spectral component. We suggest that non-thermal X-rays originate a stellar X-ray aurora due to streams of non-thermal electrons impacting on the stellar surface. Taking advantage of the relation between the spectral indices of the X-ray power-law spectrum and the non-thermal electron energy distributions, we perform 3-D modeling of the radio emission for HR5907. The wavelength-dependent radio light-curves probe magnetospheric layers at different heights above the stellar surface. A detailed comparison between simulated and observed radio light-curves leads us to conclude that the stellar magnetic field of HR5907 is likely non-dipolar, providing further indirect evidence of the complex magnetic field topology of HR5907. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.08738v1-abstract-full').style.display = 'none'; document.getElementById('1801.08738v1-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 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 13 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/1711.06263">arXiv:1711.06263</a> <span> [<a href="https://arxiv.org/pdf/1711.06263">pdf</a>, <a href="https://arxiv.org/format/1711.06263">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stx2560">10.1093/mnras/stx2560 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First Extended Catalogue of Galactic Bubbles InfraRed Fluxes from WISE and Herschel Surveys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Carey%2C+D">D. Carey</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Bulpitt%2C+A">A. Bulpitt</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Molinari%2C+S">S. Molinari</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="1711.06263v1-abstract-short" style="display: inline;"> In this paper, we present the first extended catalogue of far-infrared fluxes of Galactic bubbles. Fluxes were estimated for 1814 bubbles, defined here as the `golden sample', and were selected from the Milky Way Project First Data Release (Simpson et al.) The golden sample was comprised of bubbles identified within the Wide-field Infrared Survey Explorer (WISE) dataset (using 12- and 22-$渭$m imag… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.06263v1-abstract-full').style.display = 'inline'; document.getElementById('1711.06263v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1711.06263v1-abstract-full" style="display: none;"> In this paper, we present the first extended catalogue of far-infrared fluxes of Galactic bubbles. Fluxes were estimated for 1814 bubbles, defined here as the `golden sample', and were selected from the Milky Way Project First Data Release (Simpson et al.) The golden sample was comprised of bubbles identified within the Wide-field Infrared Survey Explorer (WISE) dataset (using 12- and 22-$渭$m images) and Herschel data (using 70-, 160-, 250-, 350- and 500-$渭$m wavelength images). Flux estimation was achieved initially via classical aperture photometry and then by an alternative image analysis algorithm that used active contours. The accuracy of the two methods was tested by comparing the estimated fluxes for a sample of bubbles, made up of 126 H II regions and 43 planetary nebulae, which were identified by Anderson et al. The results of this paper demonstrate that a good agreement between the two was found. This is by far the largest and most homogeneous catalogue of infrared fluxes measured for Galactic bubbles and it is a step towards the fully automated analysis of astronomical datasets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1711.06263v1-abstract-full').style.display = 'none'; document.getElementById('1711.06263v1-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 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 16 figures, 10 tables, published on MNRAS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> MNRAS, 473, 3671-3692 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1710.04702">arXiv:1710.04702</a> <span> [<a href="https://arxiv.org/pdf/1710.04702">pdf</a>, <a href="https://arxiv.org/format/1710.04702">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="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stx2445">10.1093/mnras/stx2445 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SCORPIO-II: Spectral indices of weak Galactic radio sources </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Franzen%2C+T+M+O">T. M. O. Franzen</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Marvil%2C+J">J. Marvil</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</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="1710.04702v1-abstract-short" style="display: inline;"> In the next few years the classification of radio sources observed by the large surveys will be a challenging problem, and spectral index is a powerful tool for addressing it. Here we present an algorithm to estimate the spectral index of sources from multiwavelength radio images. We have applied our algorithm to SCORPIO (Umana et al. 2015), a Galactic Plane survey centred around 2.1 GHz carried o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1710.04702v1-abstract-full').style.display = 'inline'; document.getElementById('1710.04702v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1710.04702v1-abstract-full" style="display: none;"> In the next few years the classification of radio sources observed by the large surveys will be a challenging problem, and spectral index is a powerful tool for addressing it. Here we present an algorithm to estimate the spectral index of sources from multiwavelength radio images. We have applied our algorithm to SCORPIO (Umana et al. 2015), a Galactic Plane survey centred around 2.1 GHz carried out with ATCA, and found we can measure reliable spectral indices only for sources stronger than 40 times the rms noise. Above a threshold of 1 mJy, the source density in SCORPIO is 20 percent greater than in a typical extra-galactic field, like ATLAS (Norris et al. 2006), because of the presence of Galactic sources. Among this excess population, 16 sources per square degree have a spectral index of about zero, suggesting optically thin thermal emission such as Hii regions and planetary nebulae, while 12 per square degree present a rising spectrum, suggesting optically thick thermal emission such as stars and UCHii regions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1710.04702v1-abstract-full').style.display = 'none'; document.getElementById('1710.04702v1-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 September, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2017. </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, 11 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/1706.01046">arXiv:1706.01046</a> <span> [<a href="https://arxiv.org/pdf/1706.01046">pdf</a>, <a href="https://arxiv.org/format/1706.01046">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/stx1357">10.1093/mnras/stx1357 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Properties of Hi-GAL clumps in the inner Galaxy]{The Hi-GAL compact source catalogue. I. The physical properties of the clumps in the inner Galaxy ($-71.0^{\circ}< \ell < 67.0^{\circ}$) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Elia%2C+D">D. Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Molinari%2C+S">S. Molinari</a>, <a href="/search/astro-ph?searchtype=author&query=Schisano%2C+E">E. Schisano</a>, <a href="/search/astro-ph?searchtype=author&query=Pestalozzi%2C+M">M. Pestalozzi</a>, <a href="/search/astro-ph?searchtype=author&query=Pezzuto%2C+S">S. Pezzuto</a>, <a href="/search/astro-ph?searchtype=author&query=Merello%2C+M">M. Merello</a>, <a href="/search/astro-ph?searchtype=author&query=Noriega-Crespo%2C+A">A. Noriega-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Moore%2C+T+J+T">T. J. T. Moore</a>, <a href="/search/astro-ph?searchtype=author&query=Russeil%2C+D">D. Russeil</a>, <a href="/search/astro-ph?searchtype=author&query=Mottram%2C+J+C">J. C. Mottram</a>, <a href="/search/astro-ph?searchtype=author&query=Paladini%2C+R">R. Paladini</a>, <a href="/search/astro-ph?searchtype=author&query=Strafella%2C+F">F. Strafella</a>, <a href="/search/astro-ph?searchtype=author&query=Benedettini%2C+M">M. Benedettini</a>, <a href="/search/astro-ph?searchtype=author&query=Bernard%2C+J+P">J. P. Bernard</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Giorgio%2C+A">A. Di Giorgio</a>, <a href="/search/astro-ph?searchtype=author&query=Eden%2C+D+J">D. J. Eden</a>, <a href="/search/astro-ph?searchtype=author&query=Fukui%2C+Y">Y. Fukui</a>, <a href="/search/astro-ph?searchtype=author&query=Plume%2C+R">R. Plume</a>, <a href="/search/astro-ph?searchtype=author&query=Bally%2C+J">J. Bally</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+P+G">P. G. Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Ragan%2C+S+E">S. E. Ragan</a>, <a href="/search/astro-ph?searchtype=author&query=Jaffa%2C+S+E">S. E. Jaffa</a>, <a href="/search/astro-ph?searchtype=author&query=Motte%2C+F">F. Motte</a>, <a href="/search/astro-ph?searchtype=author&query=Olmi%2C+L">L. Olmi</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+N">N. Schneider</a> , et al. (61 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="1706.01046v1-abstract-short" style="display: inline;"> Hi-GAL is a large-scale survey of the Galactic plane, performed with Herschel in five infrared continuum bands between 70 and 500 $渭$m. We present a band-merged catalogue of spatially matched sources and their properties derived from fits to the spectral energy distributions (SEDs) and heliocentric distances, based on the photometric catalogs presented in Molinari et al. (2016a), covering the port… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1706.01046v1-abstract-full').style.display = 'inline'; document.getElementById('1706.01046v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1706.01046v1-abstract-full" style="display: none;"> Hi-GAL is a large-scale survey of the Galactic plane, performed with Herschel in five infrared continuum bands between 70 and 500 $渭$m. We present a band-merged catalogue of spatially matched sources and their properties derived from fits to the spectral energy distributions (SEDs) and heliocentric distances, based on the photometric catalogs presented in Molinari et al. (2016a), covering the portion of Galactic plane $-71.0^{\circ}< \ell < 67.0^{\circ}$. The band-merged catalogue contains 100922 sources with a regular SED, 24584 of which show a 70 $渭$m counterpart and are thus considered proto-stellar, while the remainder are considered starless. Thanks to this huge number of sources, we are able to carry out a preliminary analysis of early stages of star formation, identifying the conditions that characterise different evolutionary phases on a statistically significant basis. We calculate surface densities to investigate the gravitational stability of clumps and their potential to form massive stars. We also explore evolutionary status metrics such as the dust temperature, luminosity and bolometric temperature, finding that these are higher in proto-stellar sources compared to pre-stellar ones. The surface density of sources follows an increasing trend as they evolve from pre-stellar to proto-stellar, but then it is found to decrease again in the majority of the most evolved clumps. Finally, we study the physical parameters of sources with respect to Galactic longitude and the association with spiral arms, finding only minor or no differences between the average evolutionary status of sources in the fourth and first Galactic quadrants, or between "on-arm" and "inter-arm" positions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1706.01046v1-abstract-full').style.display = 'none'; document.getElementById('1706.01046v1-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 June, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2017. </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 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/1705.09877">arXiv:1705.09877</a> <span> [<a href="https://arxiv.org/pdf/1705.09877">pdf</a>, <a href="https://arxiv.org/format/1705.09877">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/10.1051/0004-6361/201629963">10.1051/0004-6361/201629963 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spatial distribution of star formation related to ionized regions throughout the inner Galactic plane </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Palmeirim%2C+P">P. Palmeirim</a>, <a href="/search/astro-ph?searchtype=author&query=Zavagno%2C+A">A. Zavagno</a>, <a href="/search/astro-ph?searchtype=author&query=Elia%2C+D">D. Elia</a>, <a href="/search/astro-ph?searchtype=author&query=Moore%2C+T+J+T">T. J. T. Moore</a>, <a href="/search/astro-ph?searchtype=author&query=Whitworth%2C+A">A. Whitworth</a>, <a href="/search/astro-ph?searchtype=author&query=Tremblin%2C+P">P. Tremblin</a>, <a href="/search/astro-ph?searchtype=author&query=Traficante%2C+A">A. Traficante</a>, <a href="/search/astro-ph?searchtype=author&query=Merello%2C+M">M. Merello</a>, <a href="/search/astro-ph?searchtype=author&query=Russeil%2C+D">D. Russeil</a>, <a href="/search/astro-ph?searchtype=author&query=Pezzuto%2C+S">S. Pezzuto</a>, <a href="/search/astro-ph?searchtype=author&query=Cambr%C3%A9sy%2C+L">L. Cambr茅sy</a>, <a href="/search/astro-ph?searchtype=author&query=Baldeschi%2C+A">A. Baldeschi</a>, <a href="/search/astro-ph?searchtype=author&query=Bandieramonte%2C+M">M. Bandieramonte</a>, <a href="/search/astro-ph?searchtype=author&query=Becciani%2C+U">U. Becciani</a>, <a href="/search/astro-ph?searchtype=author&query=Benedettini%2C+M">M. Benedettini</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Bulpitt%2C+A">A. Bulpitt</a>, <a href="/search/astro-ph?searchtype=author&query=Butora%2C+R">R. Butora</a>, <a href="/search/astro-ph?searchtype=author&query=Carey%2C+D">D. Carey</a>, <a href="/search/astro-ph?searchtype=author&query=Costa%2C+A">A. Costa</a>, <a href="/search/astro-ph?searchtype=author&query=Deharveng%2C+L">L. Deharveng</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Giorgio%2C+A">A. Di Giorgio</a>, <a href="/search/astro-ph?searchtype=author&query=Eden%2C+D">D. Eden</a>, <a href="/search/astro-ph?searchtype=author&query=Hajnal%2C+A">A. Hajnal</a> , et al. (13 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1705.09877v1-abstract-short" style="display: inline;"> We present a comprehensive statistical analysis of star-forming objects located in the vicinities of 1 360 bubble structures throughout the Galactic Plane and their local environments. The compilation of ~70 000 star-forming sources, found in the proximity of the ionized (Hii) regions and detected in both Hi-GAL and GLIMPSE surveys, provided a broad overview of the different evolutionary stages of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.09877v1-abstract-full').style.display = 'inline'; document.getElementById('1705.09877v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1705.09877v1-abstract-full" style="display: none;"> We present a comprehensive statistical analysis of star-forming objects located in the vicinities of 1 360 bubble structures throughout the Galactic Plane and their local environments. The compilation of ~70 000 star-forming sources, found in the proximity of the ionized (Hii) regions and detected in both Hi-GAL and GLIMPSE surveys, provided a broad overview of the different evolutionary stages of star-formation in bubbles, from prestellar objects to more evolved young stellar objects (YSOs). Surface density maps of star-forming objects clearly reveal an evolutionary trend where more evolved star-forming objects are found spatially located near the center, while younger star-forming objects are found at the edge of the bubbles. We derived dynamic ages for a subsample of 182 Hii regions for which kinematic distances and radio continuum flux measurements were available. We detect ~80% more star-forming sources per unit area in the direction of bubbles than in the surrounding fields. We estimate ~10% clump formation efficiency (CFE) of Hi-GAL clumps in bubbles, twice the CFE in fields not affected by feedback. We find higher CFE of protostellar clumps in younger bubbles, whose density of the bubble shells is higher. We argue that the formation rate from prestellar to protostellar phase is probably higher during the early stages of the bubble expansion. Evaluation of the fragmentation time inside the shell of bubbles advocates the preexistence of clumps in the medium before the bubble, as supported by numerical simulations. Approximately 23% of the Hi-GAL clumps are found located in the direction of a bubble, with 15% for prestellar clumps and 41% for protostellar clumps. We argue that the high fraction of protostellar clumps may be due to the acceleration of the star-formation process cause by the feedback of the (Hii) bubbles. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.09877v1-abstract-full').style.display = 'none'; document.getElementById('1705.09877v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2017. </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 by Astronomy and Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 605, A35 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1704.05768">arXiv:1704.05768</a> <span> [<a href="https://arxiv.org/pdf/1704.05768">pdf</a>, <a href="https://arxiv.org/ps/1704.05768">ps</a>, <a href="https://arxiv.org/format/1704.05768">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/10.3847/1538-4357/aa72a1">10.3847/1538-4357/aa72a1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Luminous Blue Variable RMC127 as seen with ALMA and ATCA </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">G. Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Nikutta%2C+R">R. Nikutta</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bauer%2C+F+E">F. E. Bauer</a>, <a href="/search/astro-ph?searchtype=author&query=Paladini%2C+R">R. Paladini</a>, <a href="/search/astro-ph?searchtype=author&query=Noriega-Crespo%2C+A">A. Noriega-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+J+L">J. L. Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Massardi%2C+M">M. Massardi</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</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="1704.05768v4-abstract-short" style="display: inline;"> We present ALMA and ATCA observations of the luminous blue variable \rmc. The radio maps show for the first time the core of the nebula and evidence that the nebula is strongly asymmetric with a Z-pattern shape. Hints of this morphology are also visible in the archival \emph{HST} $\rm H伪$ image, which overall resembles the radio emission. The emission mechanism in the outer nebula is optically thi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.05768v4-abstract-full').style.display = 'inline'; document.getElementById('1704.05768v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1704.05768v4-abstract-full" style="display: none;"> We present ALMA and ATCA observations of the luminous blue variable \rmc. The radio maps show for the first time the core of the nebula and evidence that the nebula is strongly asymmetric with a Z-pattern shape. Hints of this morphology are also visible in the archival \emph{HST} $\rm H伪$ image, which overall resembles the radio emission. The emission mechanism in the outer nebula is optically thin free-free in the radio. At high frequencies, a component of point-source emission appears at the position of the star, up to the ALMA frequencies. The rising flux density distribution ($S_谓\sim 谓^{0.78\pm0.05}$) of this object suggests thermal emission from the ionized stellar wind and indicates a departure from spherical symmetry with $n_{e}(r)\propto r^{-2}$. We examine different scenarios to explain this excess of thermal emission from the wind and show that this can arise from a bipolar outflow, supporting the suggestion by other authors that the stellar wind of \rmc is aspherical. We fit the data with two collimated ionized wind models and we find that the mass-loss rate can be a factor of two or more smaller than in the spherical case. We also fit the photometry obtained by IR space telescopes and deduce that the mid- to far-IR emission must arise from extended, cool ($\sim80\,\rm K$) dust within the outer ionized nebula. Finally we discuss two possible scenarios for the nebular morphology: the canonical single star expanding shell geometry, and a precessing jet model assuming presence of a companion star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.05768v4-abstract-full').style.display = 'none'; document.getElementById('1704.05768v4-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 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 April, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2017. </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 ApJ (minor revision included)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.06005">arXiv:1703.06005</a> <span> [<a href="https://arxiv.org/pdf/1703.06005">pdf</a>, <a href="https://arxiv.org/ps/1703.06005">ps</a>, <a href="https://arxiv.org/format/1703.06005">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/stx690">10.1093/mnras/stx690 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Radio variability and non-thermal components in stars evolving toward planetary nebulae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</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="1703.06005v1-abstract-short" style="display: inline;"> We present new JVLA multi-frequency measurements of a set of stars in transition from the post-AGB to the Planetary Nebula phase monitored in the radio range over several years. Clear variability is found for five sources. Their light curves show increasing and decreasing patterns. New radio observations at high angular resolution are also presented for two sources. Among these is IRAS 18062+2410,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.06005v1-abstract-full').style.display = 'inline'; document.getElementById('1703.06005v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.06005v1-abstract-full" style="display: none;"> We present new JVLA multi-frequency measurements of a set of stars in transition from the post-AGB to the Planetary Nebula phase monitored in the radio range over several years. Clear variability is found for five sources. Their light curves show increasing and decreasing patterns. New radio observations at high angular resolution are also presented for two sources. Among these is IRAS 18062+2410, whose radio structure is compared to near-infrared images available in the literature. With these new maps, we can estimate inner and outer radii of 0.03$"$ and 0.08$"$ for the ionised shell, an ionised mass of $3.2\times10^{-4}$ M$_\odot$, and a density at the inner radius of $7.7\times 10^{-5}$ cm$^{-3}$, obtained by modelling the radio shell with the new morphological constraints. The combination of multi-frequency data and, where available, spectral-index maps leads to the detection of spectral indices not due to thermal emission, contrary to what one would expect in planetary nebulae. Our results allow us to hypothesise the existence of a link between radio variability and non-thermal emission mechanisms in the nebulae. This link seems to hold for IRAS 22568+6141 and may generally hold for those nebulae where the radio flux decreases over time. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.06005v1-abstract-full').style.display = 'none'; document.getElementById('1703.06005v1-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, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 9 figures, accepted for publication on 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/1701.07679">arXiv:1701.07679</a> <span> [<a href="https://arxiv.org/pdf/1701.07679">pdf</a>, <a href="https://arxiv.org/ps/1701.07679">ps</a>, <a href="https://arxiv.org/format/1701.07679">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stx267">10.1093/mnras/stx267 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The detection of variable radio emission from the fast rotating magnetic hot B-star HR7355 and evidence for its X-ray aurorae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">L. Oskinova</a>, <a href="/search/astro-ph?searchtype=author&query=Ignace%2C+R">R. Ignace</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Todt%2C+H">H. Todt</a>, <a href="/search/astro-ph?searchtype=author&query=Leone%2C+F">F. Leone</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="1701.07679v2-abstract-short" style="display: inline;"> In this paper we investigate the multiwavelengths properties of the magnetic early B-type star HR7355. We present its radio light curves at several frequencies, taken with the Jansky Very Large Array, and X-ray spectra, taken with the XMM X-ray telescope. Modeling of the radio light curves for the Stokes I and V provides a quantitative analysis of the HR7355 magnetosphere. A comparison between HR7… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.07679v2-abstract-full').style.display = 'inline'; document.getElementById('1701.07679v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1701.07679v2-abstract-full" style="display: none;"> In this paper we investigate the multiwavelengths properties of the magnetic early B-type star HR7355. We present its radio light curves at several frequencies, taken with the Jansky Very Large Array, and X-ray spectra, taken with the XMM X-ray telescope. Modeling of the radio light curves for the Stokes I and V provides a quantitative analysis of the HR7355 magnetosphere. A comparison between HR7355 and a similar analysis for the Ap star CUVir, allows us to study how the different physical parameters of the two stars affect the structure of the respective magnetospheres where the non-thermal electrons originate. Our model includes a cold thermal plasma component that accumulates at high magnetic latitudes that influences the radio regime, but does not give rise to X-ray emission. Instead, the thermal X-ray emission arises from shocks generated by wind stream collisions close to the magnetic equatorial plane. The analysis of the X-ray spectrum of HR7355 also suggests the presence of a non-thermal radiation. Comparison between the spectral index of the power-law X-ray energy distribution with the non-thermal electron energy distribution indicates that the non-thermal X-ray component could be the auroral signature of the non-thermal electrons that impact the stellar surface, the same non-thermal electrons that are responsible for the observed radio emission. On the basis of our analysis, we suggest a novel model that simultaneously explains the X-ray and the radio features of HR7355 and is likely relevant for magnetospheres of other magnetic early type stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.07679v2-abstract-full').style.display = 'none'; document.getElementById('1701.07679v2-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 February, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 January, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2017. </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 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/1612.09472">arXiv:1612.09472</a> <span> [<a href="https://arxiv.org/pdf/1612.09472">pdf</a>, <a href="https://arxiv.org/ps/1612.09472">ps</a>, <a href="https://arxiv.org/format/1612.09472">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </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/10.1051/0004-6361/201629540">10.1051/0004-6361/201629540 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ahnen%2C+M+L">M. L. Ahnen</a>, <a href="/search/astro-ph?searchtype=author&query=Ansoldi%2C+S">S. Ansoldi</a>, <a href="/search/astro-ph?searchtype=author&query=Antonelli%2C+L+A">L. A. Antonelli</a>, <a href="/search/astro-ph?searchtype=author&query=Antoranz%2C+P">P. Antoranz</a>, <a href="/search/astro-ph?searchtype=author&query=Babic%2C+A">A. Babic</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+B">B. Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Bangale%2C+P">P. Bangale</a>, <a href="/search/astro-ph?searchtype=author&query=de+Almeida%2C+U+B">U. Barres de Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Barrio%2C+J+A">J. A. Barrio</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+J+B">J. Becerra Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Bednarek%2C+W">W. Bednarek</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+E">E. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Berti%2C+A">A. Berti</a>, <a href="/search/astro-ph?searchtype=author&query=Biasuzzi%2C+B">B. Biasuzzi</a>, <a href="/search/astro-ph?searchtype=author&query=Biland%2C+A">A. Biland</a>, <a href="/search/astro-ph?searchtype=author&query=Blanch%2C+O">O. Blanch</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnefoy%2C+S">S. Bonnefoy</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnoli%2C+G">G. Bonnoli</a>, <a href="/search/astro-ph?searchtype=author&query=Borracci%2C+F">F. Borracci</a>, <a href="/search/astro-ph?searchtype=author&query=Bretz%2C+T">T. Bretz</a>, <a href="/search/astro-ph?searchtype=author&query=Buson%2C+S">S. Buson</a>, <a href="/search/astro-ph?searchtype=author&query=Carosi%2C+A">A. Carosi</a>, <a href="/search/astro-ph?searchtype=author&query=Chatterjee%2C+A">A. Chatterjee</a>, <a href="/search/astro-ph?searchtype=author&query=Clavero%2C+R">R. Clavero</a>, <a href="/search/astro-ph?searchtype=author&query=Colin%2C+P">P. Colin</a> , et al. (268 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="1612.09472v1-abstract-short" style="display: inline;"> We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1 which includes, among other instruments, MAGIC, VERITAS, Whipple 10-m, Fermi-LAT, RXTE, Swift, GASP-WEBT and VLBA. We find an increase in the fractional variability with energy, while no significant interband correlations of flux… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.09472v1-abstract-full').style.display = 'inline'; document.getElementById('1612.09472v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1612.09472v1-abstract-full" style="display: none;"> We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1 which includes, among other instruments, MAGIC, VERITAS, Whipple 10-m, Fermi-LAT, RXTE, Swift, GASP-WEBT and VLBA. We find an increase in the fractional variability with energy, while no significant interband correlations of flux changes are found in the acquired data set. The higher variability in the very high energy (>100 GeV, VHE) gamma-ray emission and the lack of correlation with the X-ray emission indicate that the highest-energy electrons that are responsible for the VHE gamma-rays do not make a dominant contribution to the ~1 keV emission. Alternatively, there could be a very variable component contributing to the VHE gamma-ray emission in addition to that coming from the synchrotron self-Compton (SSC) scenarios. The space of SSC model parameters is probed following a dedicated grid-scan strategy, allowing for a wide range of models to be tested and offering a study of the degeneracy of model-to-data agreement in the individual model parameters. We find that there is some degeneracy in both the one-zone and the two-zone SSC scenarios that were probed, with several combinations of model parameters yielding a similar model-to-data agreement, and some parameters better constrained than others. The SSC model grid-scan shows that the flaring activity around 2009 May 22 cannot be modeled adequately with a one-zone SSC scenario, while it can be suitably described within a two-independent-zone SSC scenario. The observation of an electric vector polarization angle rotation coincident with the gamma-ray flare from 2009 May 1 resembles those reported previously for low frequency peaked blazars, hence suggesting that there are many similarities in the flaring mechanisms of blazars with different jet properties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.09472v1-abstract-full').style.display = 'none'; document.getElementById('1612.09472v1-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 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2016. </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, 15 figures, accepted for publication in A&A. Corresponding authors: Marlene Doert (marlene.doert@tu-dortmund.de) and David Paneque (dpaneque@mppmu.mpg.de)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 603, A31 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1612.05039">arXiv:1612.05039</a> <span> [<a href="https://arxiv.org/pdf/1612.05039">pdf</a>, <a href="https://arxiv.org/ps/1612.05039">ps</a>, <a href="https://arxiv.org/format/1612.05039">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/stw3074">10.1093/mnras/stw3074 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Exploring the multifaceted circumstellar environment of the Luminous Blue Variable HR Carinae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Molinari%2C+S">S. Molinari</a>, <a href="/search/astro-ph?searchtype=author&query=Schillir%C3%B2%2C+F">F. Schillir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="1612.05039v1-abstract-short" style="display: inline;"> We present a multi-wavelength study of the Galactic Luminous Blue Variable HR Carinae, based on new high resolution mid-infrared (IR) and radio images obtained with the Very Large Telescope (VLT) and the Australia Telescope Compact Array (ATCA), which have been complemented by far-infrared Herschel-PACS observations and ATCA archive data. The Herschel images reveal the large-scale distribution of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.05039v1-abstract-full').style.display = 'inline'; document.getElementById('1612.05039v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1612.05039v1-abstract-full" style="display: none;"> We present a multi-wavelength study of the Galactic Luminous Blue Variable HR Carinae, based on new high resolution mid-infrared (IR) and radio images obtained with the Very Large Telescope (VLT) and the Australia Telescope Compact Array (ATCA), which have been complemented by far-infrared Herschel-PACS observations and ATCA archive data. The Herschel images reveal the large-scale distribution of the dusty emitting nebula, which extends mainly to the North-East direction, up to 70 arcsec from the central star, and is oriented along the direction of the space motion of the star. In the mid-infrared images, the brightness distribution is characterized by two arc-shaped structures, tracing an inner envelope surrounding the central star more closely. At radio wavelengths, the ionized gas emission lies on the opposite side of the cold dust with respect to the position of the star, as if the ionized front was confined by the surrounding medium in the North-South direction. The comparison with previous data indicates significant changes in the radio nebula morphology and in the mass-loss rate from the central star, which has increased from 6.1$\times10^{-6}$ M$_{\odot}$yr$^{-1}$ in 1994-1995 to $1.17\times10^{-5}$ M$_{\odot}$yr$^{-1}$ in 2014. We investigate possible scenarios that could have generated the complex circumstellar environment revealed by our multi-wavelength data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.05039v1-abstract-full').style.display = 'none'; document.getElementById('1612.05039v1-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 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2016. </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">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/1611.05259">arXiv:1611.05259</a> <span> [<a href="https://arxiv.org/pdf/1611.05259">pdf</a>, <a href="https://arxiv.org/ps/1611.05259">ps</a>, <a href="https://arxiv.org/format/1611.05259">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/stw2986">10.1093/mnras/stw2986 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> New ATCA, ALMA and VISIR observations of the candidate LBV SK-67266 (S61): the nebular mass from modelling 3D density distributions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Nikutta%2C+R">R. Nikutta</a>, <a href="/search/astro-ph?searchtype=author&query=Pignata%2C+G">G. Pignata</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+N+M">N. M. Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Noriega-Crespo%2C+A">A. Noriega-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Paladini%2C+R">R. Paladini</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</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="1611.05259v2-abstract-short" style="display: inline;"> We present new observations of the nebula around the Magellanic candidate Luminous Blue Variable S61. These comprise high-resolution data acquired with the Australia Telescope Compact Array (ATCA), the Atacama Large Millimetre/Submillimetre Array (ALMA), and VISIR at the Very Large Telescope (VLT). The nebula was detected only in the radio, up to 17 GHz. The 17 GHz ATCA map, with 0.8 arcsec resolu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.05259v2-abstract-full').style.display = 'inline'; document.getElementById('1611.05259v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1611.05259v2-abstract-full" style="display: none;"> We present new observations of the nebula around the Magellanic candidate Luminous Blue Variable S61. These comprise high-resolution data acquired with the Australia Telescope Compact Array (ATCA), the Atacama Large Millimetre/Submillimetre Array (ALMA), and VISIR at the Very Large Telescope (VLT). The nebula was detected only in the radio, up to 17 GHz. The 17 GHz ATCA map, with 0.8 arcsec resolution, allowed a morphological comparison with the H$伪$ Hubble Space Telescope image. The radio nebula resembles a spherical shell, as in the optical. The spectral index map indicates that the radio emission is due to free-free transitions in the ionised, optically thin gas, but there are hints of inhomogeneities. We present our new public code RHOCUBE to model 3D density distributions, and determine via Bayesian inference the nebula's geometric parameters. We applied the code to model the electron density distribution in the S61 nebula. We found that different distributions fit the data, but all of them converge to the same ionised mass, ~0.1 $\rm M\odot$, which is an order of magnitude smaller than previous estimates. We show how the nebula models can be used to derive the mass-loss history with high-temporal resolution. The nebula was probably formed through stellar winds, rather than eruptions. From the ALMA and VISIR non-detections, plus the derived extinction map, we deduce that the infrared emission observed by space telescopes must arise from extended, diffuse dust within the ionised region. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.05259v2-abstract-full').style.display = 'none'; document.getElementById('1611.05259v2-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 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2016. </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, 9 figures. Authors list corrected. In press in MNRAS. RHOCUBE code available online ( https://github.com/rnikutta/rhocube )</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1611.00511">arXiv:1611.00511</a> <span> [<a href="https://arxiv.org/pdf/1611.00511">pdf</a>, <a href="https://arxiv.org/ps/1611.00511">ps</a>, <a href="https://arxiv.org/format/1611.00511">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stx995">10.1093/mnras/stx995 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Probing the magnetosphere of the M8.5 dwarf TVLM513-46546 by modelling its auroral radio emission. Hint of star exoplanet interaction? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</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="1611.00511v3-abstract-short" style="display: inline;"> In this paper we simulate the cyclic circularly-polarised pulses of the ultra-cool dwarf TVLM513-46546, observed with the VLA at 4.88 and 8.44 GHz on May 2006, by using a 3D model of the auroral radio emission from the stellar magnetosphere. During this epoch, the radio light curves are characterised by two pulses left-hand polarised at 4.88 GHz, and one doubly-peaked (of opposite polarisations) p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.00511v3-abstract-full').style.display = 'inline'; document.getElementById('1611.00511v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1611.00511v3-abstract-full" style="display: none;"> In this paper we simulate the cyclic circularly-polarised pulses of the ultra-cool dwarf TVLM513-46546, observed with the VLA at 4.88 and 8.44 GHz on May 2006, by using a 3D model of the auroral radio emission from the stellar magnetosphere. During this epoch, the radio light curves are characterised by two pulses left-hand polarised at 4.88 GHz, and one doubly-peaked (of opposite polarisations) pulse at 8.44 GHz. To take into account the possible deviation from the dipolar symmetry of the stellar magnetic field topology, the model described in this paper is also able to simulate the auroral radio emission from a magnetosphere shaped like an offset-dipole. To reproduce the timing and pattern of the observed pulses, we explored the space of parameters controlling the auroral beaming pattern and the geometry of the magnetosphere. Through the analysis of the TVLM513-46546 auroral radio emission, we derive some indications on the magnetospheric field topology that is able to simultaneously reproduce the timing and patterns of the auroral pulses measured at 4.88 and 8.44 GHz. Each set of model solutions simulates two auroral pulses (singly or doubly peaked) per period. To explain the presence of only one 8.44 GHz pulse per period, we analyse the case of auroral radio emission limited only to a magnetospheric sector activated by an external body, like the case of the interaction of Jupiter with its moons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.00511v3-abstract-full').style.display = 'none'; document.getElementById('1611.00511v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2016. </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; 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/1609.00003">arXiv:1609.00003</a> <span> [<a href="https://arxiv.org/pdf/1609.00003">pdf</a>, <a href="https://arxiv.org/format/1609.00003">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stw2053">10.1093/mnras/stw2053 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High-resolution Very Large Array observations of 18 MIPSGAL bubbles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">Adriano Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">Corrado Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">Grazia Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">Carla Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">Filomena Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">Claudia Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">Simone Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Flagey%2C+N">Nicolas Flagey</a>, <a href="/search/astro-ph?searchtype=author&query=Silva%2C+K">Kevin Silva</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">Luciano Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">Francesco Cavallaro</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="1609.00003v1-abstract-short" style="display: inline;"> We present radio observations of 18 MIPSGAL bubbles performed at 5 GHz (6 cm) with the Karl G. Jansky Very Large Array in configuration B and BnA. The observations were aimed at understanding what kind of information high-resolution and high-sensitivity radio maps can supply on the circumstellar envelopes of different kinds of evolved stars and what their comparison with infrared images with simil… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1609.00003v1-abstract-full').style.display = 'inline'; document.getElementById('1609.00003v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1609.00003v1-abstract-full" style="display: none;"> We present radio observations of 18 MIPSGAL bubbles performed at 5 GHz (6 cm) with the Karl G. Jansky Very Large Array in configuration B and BnA. The observations were aimed at understanding what kind of information high-resolution and high-sensitivity radio maps can supply on the circumstellar envelopes of different kinds of evolved stars and what their comparison with infrared images with similar resolution can tell us. We found that the 18 bubbles can be grouped into five categories according to their radio morphology. The three bubbles presenting a central point source in the radio images all correspond to luminous blue variable star candidates. Eleven bubbles show an elliptical shape and the total lack of a central object in the radio, and are likely associated with planetary nebulae. Under this assumption we derive their distance, their ionized mass and their distribution on the Galactic plane. We discuss the possibility that the MIPSGAL bubbles catalogue (428 objects) may contain a large fraction of all Galactic planetary nebulae located at a distance between 1.4 kpc and 6.9 kpc and lying in the MIPSGAL field of view. Among the remaining bubbles we identify also a H II region and a proto-planetary nebula candidate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1609.00003v1-abstract-full').style.display = 'none'; document.getElementById('1609.00003v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2016. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1605.01852">arXiv:1605.01852</a> <span> [<a href="https://arxiv.org/pdf/1605.01852">pdf</a>, <a href="https://arxiv.org/format/1605.01852">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 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/stw982">10.1093/mnras/stw982 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Automated detection of extended sources in radio maps: progress from the SCORPIO survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Riggi%2C+S">S. Riggi</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Bufano%2C+F">F. Bufano</a>, <a href="/search/astro-ph?searchtype=author&query=Schillir%C3%B2%2C+F">F. Schillir貌</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</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="1605.01852v1-abstract-short" style="display: inline;"> Automated source extraction and parameterization represents a crucial challenge for the next-generation radio interferometer surveys, such as those performed with the Square Kilometre Array (SKA) and its precursors. In this paper we present a new algorithm, dubbed CAESAR (Compact And Extended Source Automated Recognition), to detect and parametrize extended sources in radio interferometric maps. I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1605.01852v1-abstract-full').style.display = 'inline'; document.getElementById('1605.01852v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1605.01852v1-abstract-full" style="display: none;"> Automated source extraction and parameterization represents a crucial challenge for the next-generation radio interferometer surveys, such as those performed with the Square Kilometre Array (SKA) and its precursors. In this paper we present a new algorithm, dubbed CAESAR (Compact And Extended Source Automated Recognition), to detect and parametrize extended sources in radio interferometric maps. It is based on a pre-filtering stage, allowing image denoising, compact source suppression and enhancement of diffuse emission, followed by an adaptive superpixel clustering stage for final source segmentation. A parameterization stage provides source flux information and a wide range of morphology estimators for post-processing analysis. We developed CAESAR in a modular software library, including also different methods for local background estimation and image filtering, along with alternative algorithms for both compact and diffuse source extraction. The method was applied to real radio continuum data collected at the Australian Telescope Compact Array (ATCA) within the SCORPIO project, a pathfinder of the ASKAP-EMU survey. The source reconstruction capabilities were studied over different test fields in the presence of compact sources, imaging artefacts and diffuse emission from the Galactic plane and compared with existing algorithms. When compared to a human-driven analysis, the designed algorithm was found capable of detecting known target sources and regions of diffuse emission, outperforming alternative approaches over the considered fields. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1605.01852v1-abstract-full').style.display = 'none'; document.getElementById('1605.01852v1-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 May, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 9 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> MNRAS (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1603.02423">arXiv:1603.02423</a> <span> [<a href="https://arxiv.org/pdf/1603.02423">pdf</a>, <a href="https://arxiv.org/ps/1603.02423">ps</a>, <a href="https://arxiv.org/format/1603.02423">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stw639">10.1093/mnras/stw639 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> 3D-modelling of the stellar auroral radio emission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</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="1603.02423v1-abstract-short" style="display: inline;"> The electron cyclotron maser is the coherent emission process that gives rise to the radio lighthouse effect observed in the hot magnetic chemically peculiar star CU Virginis. It has also been proposed to explain the highly circularly polarized radio pulses observed on some ultra cool dwarfs, with spectral type earlier than M7. Such kind of coherent events resemble the auroral radio emission from… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1603.02423v1-abstract-full').style.display = 'inline'; document.getElementById('1603.02423v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1603.02423v1-abstract-full" style="display: none;"> The electron cyclotron maser is the coherent emission process that gives rise to the radio lighthouse effect observed in the hot magnetic chemically peculiar star CU Virginis. It has also been proposed to explain the highly circularly polarized radio pulses observed on some ultra cool dwarfs, with spectral type earlier than M7. Such kind of coherent events resemble the auroral radio emission from the magnetized planets of the solar system. In this paper, we present a tridimensional model able to simulate the timing and profile of the pulses emitted by those stars characterized by a dipolar magnetic field by following the hypothesis of the laminar source model, used to explain the beaming of the terrestrial auroral kilometric radiation. This model proves to be a powerful tool to understand the auroral radio-emission phenomenon, allowing us to derive some general conclusions about the effects of the model's free parameters on the features of the coherent pulses, and to learn more about the detectability of such kind of pulsed radio emission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1603.02423v1-abstract-full').style.display = 'none'; document.getElementById('1603.02423v1-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 March, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 8 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/1510.00134">arXiv:1510.00134</a> <span> [<a href="https://arxiv.org/pdf/1510.00134">pdf</a>, <a href="https://arxiv.org/format/1510.00134">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stv1878">10.1093/mnras/stv1878 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Searching for OH maser emission towards the MIPSGAL compact Galactic bubbles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">C. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</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="1510.00134v1-abstract-short" style="display: inline;"> We conducted radio observations searching for OH 18-cm maser emission from a sample of 169 unclassified MIPSGAL compact Galactic bubbles. These sources are thought to be the circumstellar envelopes of different kinds of evolved stars. Our observations were aimed at shedding light on the nature of MIPSGAL bubbles, since their characterisation is a fundamental aid for the development of accurate phy… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.00134v1-abstract-full').style.display = 'inline'; document.getElementById('1510.00134v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1510.00134v1-abstract-full" style="display: none;"> We conducted radio observations searching for OH 18-cm maser emission from a sample of 169 unclassified MIPSGAL compact Galactic bubbles. These sources are thought to be the circumstellar envelopes of different kinds of evolved stars. Our observations were aimed at shedding light on the nature of MIPSGAL bubbles, since their characterisation is a fundamental aid for the development of accurate physical models of stellar and Galaxy evolution. The maser emission is observatively linked to the last stages of the life of low- and intermediate-mass stars, which may constitute a significant fraction of the MIPSGAL bubbles. In particular OH masers are usually observed towards post-AGB stars. Our observations were performed with the Green Bank Telescope and, for each source, produced spectra around the four OH 18-cm transitions. The observations were compared with archive interferometer data in order to exclude possible contamination from nearby sources. The main result is that the OH maser emission is not a common feature among the MIPSGAL bubbles, with only one certain detection. We conclude that among the MIPSGAL bubbles the post-AGB stars could be very rare. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.00134v1-abstract-full').style.display = 'none'; document.getElementById('1510.00134v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 October, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2015. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1506.04531">arXiv:1506.04531</a> <span> [<a href="https://arxiv.org/pdf/1506.04531">pdf</a>, <a href="https://arxiv.org/ps/1506.04531">ps</a>, <a href="https://arxiv.org/format/1506.04531">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stv1976">10.1093/mnras/stv1976 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> SCORPIO: A deep survey of Radio Emission from the stellar life-cycle </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">G. Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">C. Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Franzen%2C+T+M+O">T. M. O. Franzen</a>, <a href="/search/astro-ph?searchtype=author&query=Norris%2C+R+P">R. P. Norris</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">P. Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">A. Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C+S">C. S. Buemi</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">C. Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Cavallaro%2C+F">F. Cavallaro</a>, <a href="/search/astro-ph?searchtype=author&query=Cerrigone%2C+L">L. Cerrigone</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="1506.04531v1-abstract-short" style="display: inline;"> Radio emission has been detected in a broad variety of stellar objects from all stages of stellar evolution. However, most of our knowledge originates from targeted observations of small samples, which are strongly biased to sources which are peculiar at other wavelengths. In order to tackle this problem we have conducted a deep 1.4 GHz survey by using the Australian Telescope Compact Array (ATCA)… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1506.04531v1-abstract-full').style.display = 'inline'; document.getElementById('1506.04531v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1506.04531v1-abstract-full" style="display: none;"> Radio emission has been detected in a broad variety of stellar objects from all stages of stellar evolution. However, most of our knowledge originates from targeted observations of small samples, which are strongly biased to sources which are peculiar at other wavelengths. In order to tackle this problem we have conducted a deep 1.4 GHz survey by using the Australian Telescope Compact Array (ATCA), following the same observing setup as that used for the Australia Telescope Large Area Survey (ATLAS) project, this time choosing a region more appropriate for stellar work. In this paper, the SCORPIO project is presented as well as results from the pilot experiment. The achieved rms is about 30 /uJy and the angular resolution ~10 arcsec. About six hundred of point-like sources have been extracted just from the pilot field. A very small percentage of them are classified in SIMBAD or the NASA/IPAC Extragalactic Database (NED). About 80 % of the extracted sources are reported in one of the inspected catalogues and 50 % of them appears to belong to a reddened stellar/galactic population. The evaluation of extragalactic contaminants is very difficult without further investigations. Interesting results have been obtained for extended radio sources that fall in the SCORPIO field. Many bubble-like structures have been found, some of which are classified at other wavelengths. However, for all of these sources, our project has provided us with images of unprecedented sensitivity and angular resolution at 2.1 GHz. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1506.04531v1-abstract-full').style.display = 'none'; document.getElementById('1506.04531v1-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 June, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 9 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/1410.6391">arXiv:1410.6391</a> <span> [<a href="https://arxiv.org/pdf/1410.6391">pdf</a>, <a href="https://arxiv.org/ps/1410.6391">ps</a>, <a href="https://arxiv.org/format/1410.6391">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </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/10.1051/0004-6361/201322906">10.1051/0004-6361/201322906 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multiwavelength observations of Mrk 501 in 2008 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=MAGIC+Collaboration"> MAGIC Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Aleksi%C4%87%2C+J">J. Aleksi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Ansoldi%2C+S">S. Ansoldi</a>, <a href="/search/astro-ph?searchtype=author&query=Antonelli%2C+L+A">L. A. Antonelli</a>, <a href="/search/astro-ph?searchtype=author&query=Antoranz%2C+P">P. Antoranz</a>, <a href="/search/astro-ph?searchtype=author&query=Babic%2C+A">A. Babic</a>, <a href="/search/astro-ph?searchtype=author&query=Bangale%2C+P">P. Bangale</a>, <a href="/search/astro-ph?searchtype=author&query=de+Almeida%2C+U+B">U. Barres de Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Barrio%2C+J+A">J. A. Barrio</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+J+B">J. Becerra Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Bednarek%2C+W">W. Bednarek</a>, <a href="/search/astro-ph?searchtype=author&query=Berger%2C+K">K. Berger</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+E">E. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Biland%2C+A">A. Biland</a>, <a href="/search/astro-ph?searchtype=author&query=Blanch%2C+O">O. Blanch</a>, <a href="/search/astro-ph?searchtype=author&query=Bock%2C+R+K">R. K. Bock</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnefoy%2C+S">S. Bonnefoy</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnoli%2C+G">G. Bonnoli</a>, <a href="/search/astro-ph?searchtype=author&query=Borracci%2C+F">F. Borracci</a>, <a href="/search/astro-ph?searchtype=author&query=Bretz%2C+T">T. Bretz</a>, <a href="/search/astro-ph?searchtype=author&query=Carmona%2C+E">E. Carmona</a>, <a href="/search/astro-ph?searchtype=author&query=Carosi%2C+A">A. Carosi</a>, <a href="/search/astro-ph?searchtype=author&query=Fidalgo%2C+D+C">D. Carreto Fidalgo</a>, <a href="/search/astro-ph?searchtype=author&query=Colin%2C+P">P. Colin</a>, <a href="/search/astro-ph?searchtype=author&query=Colombo%2C+E">E. Colombo</a> , et al. (237 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="1410.6391v1-abstract-short" style="display: inline;"> Mrk 501 is one of the brightest blazars at TeV energies and has been extensively studied since its first VHE detection in 1996. Our goal is to characterize in detail the source gamma-ray emission, together with the radio-to-X-ray emission, during the non-flaring (low) activity, which is less often studied than the occasional flaring (high) activity. We organized a multiwavelength (MW) campaign on… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1410.6391v1-abstract-full').style.display = 'inline'; document.getElementById('1410.6391v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1410.6391v1-abstract-full" style="display: none;"> Mrk 501 is one of the brightest blazars at TeV energies and has been extensively studied since its first VHE detection in 1996. Our goal is to characterize in detail the source gamma-ray emission, together with the radio-to-X-ray emission, during the non-flaring (low) activity, which is less often studied than the occasional flaring (high) activity. We organized a multiwavelength (MW) campaign on Mrk 501 between March and May 2008. This multi-instrument effort included the most sensitive VHE gamma-ray instruments in the northern hemisphere, namely the imaging atmospheric Cherenkov telescopes MAGIC and VERITAS, as well as Swift, RXTE, the F-GAMMA, GASP-WEBT, and other collaborations and instruments. Mrk 501 was found to be in a low state of activity during the campaign, with a VHE flux in the range of 10%-20% of the Crab nebula flux. Nevertheless, significant flux variations were detected with various instruments, with a trend of increasing variability with energy. The broadband spectral energy distribution during the two different emission states of the campaign can be adequately described within the homogeneous one-zone synchrotron self-Compton model, with the (slightly) higher state described by an increase in the electron number density. This agrees with previous studies of the broadband emission of this source during flaring and non-flaring states. We report for the first time a tentative X-ray-to-VHE correlation during a low VHE activity. Although marginally significant, this positive correlation between X-ray and VHE, which has been reported many times during flaring activity, suggests that the mechanisms that dominate the X-ray/VHE emission during non-flaring-activity are not substantially different from those that are responsible for the emission during flaring activity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1410.6391v1-abstract-full').style.display = 'none'; document.getElementById('1410.6391v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 October, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2014. </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</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> MPP-2014-381 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1410.1315">arXiv:1410.1315</a> <span> [<a href="https://arxiv.org/pdf/1410.1315">pdf</a>, <a href="https://arxiv.org/format/1410.1315">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/10.1093/mnras/stu2081">10.1093/mnras/stu2081 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Study of the extended radio emission of two supernova remnants and four planetary nebulae associated to MIPSGAL bubbles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ingallinera%2C+A">Adriano Ingallinera</a>, <a href="/search/astro-ph?searchtype=author&query=Trigilio%2C+C">Corrado Trigilio</a>, <a href="/search/astro-ph?searchtype=author&query=Umana%2C+G">Grazia Umana</a>, <a href="/search/astro-ph?searchtype=author&query=Leto%2C+P">Paolo Leto</a>, <a href="/search/astro-ph?searchtype=author&query=Agliozzo%2C+C">Claudia Agliozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Buemi%2C+C">Carla Buemi</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="1410.1315v1-abstract-short" style="display: inline;"> We present radio observations of two supernova remnants and four planetary nebulae with the Very Large Array and the Green Bank Telescope. These objects are part of a larger sample of radio sources, discussed in a previous paper, counterpart of the MIPSGAL 24-micron compact bubbles. For the two supernova remnants we combined the interferometric observations with single-dish data to obtain both a h… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1410.1315v1-abstract-full').style.display = 'inline'; document.getElementById('1410.1315v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1410.1315v1-abstract-full" style="display: none;"> We present radio observations of two supernova remnants and four planetary nebulae with the Very Large Array and the Green Bank Telescope. These objects are part of a larger sample of radio sources, discussed in a previous paper, counterpart of the MIPSGAL 24-micron compact bubbles. For the two supernova remnants we combined the interferometric observations with single-dish data to obtain both a high resolution and a good sensitivity to extended structures. We discuss in detail the entire combination procedure adopted and the reliability of the resulting maps. For one supernova remnant we pose a more stringent upper limit for the flux density of its undetected pulsar, and we also show prominent spectral index spatial variations, probably due to inhomogeneities in the magnetic field and in its ejecta or to an interaction between the supernova shock and molecular clouds. We eventually use the 5-GHz maps of the four planetary nebulae to estimate their distance and their ionized mass. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1410.1315v1-abstract-full').style.display = 'none'; document.getElementById('1410.1315v1-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 October, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2014. </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=Leto%2C+P&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Leto%2C+P&start=0" class="pagination-link is-current" 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