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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=Romano%2C+P&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=150" class="pagination-link " aria-label="Page 4" aria-current="page">4 </a> </li> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=200" class="pagination-link " aria-label="Page 5" aria-current="page">5 </a> </li> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=250" class="pagination-link " aria-label="Page 6" aria-current="page">6 </a> </li> <li> <a href="/search/?searchtype=author&query=Romano%2C+P&start=300" class="pagination-link " aria-label="Page 7" aria-current="page">7 </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/2409.07261">arXiv:2409.07261</a> <span> [<a href="https://arxiv.org/pdf/2409.07261">pdf</a>, <a href="https://arxiv.org/format/2409.07261">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Photospheric signatures of CME onset </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ottupara%2C+A">Aslam Ottupara</a>, <a href="/search/astro-ph?searchtype=author&query=MacTaggart%2C+D">David MacTaggart</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+T">Tom Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Fletcher%2C+L">Lyndsay Fletcher</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</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="2409.07261v1-abstract-short" style="display: inline;"> Coronal mass ejections (CMEs) are solar eruptions that involve large-scale changes to the magnetic topology of an active region. There exists a range of models for CME onset which are based on twisted or sheared magnetic field above a polarity inversion line (PIL). We present observational evidence that topological changes at PILs, in the photosphere, form a key part of CME onset, as implied by ma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.07261v1-abstract-full').style.display = 'inline'; document.getElementById('2409.07261v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.07261v1-abstract-full" style="display: none;"> Coronal mass ejections (CMEs) are solar eruptions that involve large-scale changes to the magnetic topology of an active region. There exists a range of models for CME onset which are based on twisted or sheared magnetic field above a polarity inversion line (PIL). We present observational evidence that topological changes at PILs, in the photosphere, form a key part of CME onset, as implied by many models. In particular, we study the onset of 30 CMEs and investigate topological changes in the photosphere by calculating the magnetic winding flux, using the \texttt{ARTop} code. By matching the times and locations of winding signatures with CME observations produced by the \texttt{ALMANAC} code, we confirm that these signatures are indeed associated with CMEs. Therefore, as well as presenting evidence that changes in magnetic topology at the photosphere are a common signature of CME onset, our approach also allows for the finding of the source location of a CME within an active region. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.07261v1-abstract-full').style.display = 'none'; document.getElementById('2409.07261v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 September, 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 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/2409.04408">arXiv:2409.04408</a> <span> [<a href="https://arxiv.org/pdf/2409.04408">pdf</a>, <a href="https://arxiv.org/ps/2409.04408">ps</a>, <a href="https://arxiv.org/format/2409.04408">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="Space Physics">physics.space-ph</span> </div> </div> <p class="title is-5 mathjax"> Analyzing the Sequence of Phases Leading to the Formation of the Active Region 13664, with Potential Carrington-like Characteristics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Elmhamdi%2C+A">Abouazza Elmhamdi</a>, <a href="/search/astro-ph?searchtype=author&query=Marassi%2C+A">Alessandro Marassi</a>, <a href="/search/astro-ph?searchtype=author&query=Contarino%2C+L">Lidia Contarino</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="2409.04408v2-abstract-short" style="display: inline;"> Several recurrent X-class flares from Active Region (AR) 13664 have triggered a severe G5-class geomagnetic storm between May 10 and 11, 2024. The morphology and compactness of this AR closely resemble the active region responsible for the famous Carrington Event of 1859. Although the induced geomagnetic currents produced a value of the Dst index, probably, an order of magnitude weaker than that o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.04408v2-abstract-full').style.display = 'inline'; document.getElementById('2409.04408v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.04408v2-abstract-full" style="display: none;"> Several recurrent X-class flares from Active Region (AR) 13664 have triggered a severe G5-class geomagnetic storm between May 10 and 11, 2024. The morphology and compactness of this AR closely resemble the active region responsible for the famous Carrington Event of 1859. Although the induced geomagnetic currents produced a value of the Dst index, probably, an order of magnitude weaker than that of the Carrington Event, the characteristics of AR 13664 warrant special attention. Understanding the mechanisms of magnetic field emergence and transformation in the solar atmosphere that lead to the formation of such an extensive, compact and complex AR is crucial. Our analysis of the emerging flux and horizontal motions of the magnetic structures observed in the photosphere reveals the fundamental role of a sequence of emerging bipoles at the same latitude and longitude, followed by converging and shear motions. This temporal order of processes frequently invoked in magnetohydrodynamic models - emergence, converging motions, and shear motions - is critical for the storage of magnetic energy preceding strong solar eruptions that, under the right timing, location and direction conditions, can trigger severe space weather events at Earth. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.04408v2-abstract-full').style.display = 'none'; document.getElementById('2409.04408v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 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">25 pages, 5 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/2403.04857">arXiv:2403.04857</a> <span> [<a href="https://arxiv.org/pdf/2403.04857">pdf</a>, <a href="https://arxiv.org/format/2403.04857">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 Physics - Phenomenology">hep-ph</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="High Energy Physics - Experiment">hep-ex</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/10.1088/1475-7516/2024/07/047">10.1088/1475-7516/2024/07/047 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Dark Matter Line Searches with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Abe%2C+S">S. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Abhir%2C+J">J. Abhir</a>, <a href="/search/astro-ph?searchtype=author&query=Abhishek%2C+A">A. Abhishek</a>, <a href="/search/astro-ph?searchtype=author&query=Acero%2C+F">F. Acero</a>, <a href="/search/astro-ph?searchtype=author&query=Acharyya%2C+A">A. Acharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Adam%2C+R">R. Adam</a>, <a href="/search/astro-ph?searchtype=author&query=Aguasca-Cabot%2C+A">A. Aguasca-Cabot</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Aguirre-Santaella%2C+A">A. Aguirre-Santaella</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+J">J. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+R">R. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alvarez-Crespo%2C+N">N. Alvarez-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amans%2C+J+-">J. -P. Amans</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Ambrosi%2C+G">G. Ambrosi</a>, <a href="/search/astro-ph?searchtype=author&query=Angel%2C+L">L. Angel</a>, <a href="/search/astro-ph?searchtype=author&query=Aramo%2C+C">C. Aramo</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Arnesen%2C+T+T+H">T. T. H. Arnesen</a>, <a href="/search/astro-ph?searchtype=author&query=Arrabito%2C+L">L. Arrabito</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+K">K. Asano</a>, <a href="/search/astro-ph?searchtype=author&query=Ascasibar%2C+Y">Y. Ascasibar</a>, <a href="/search/astro-ph?searchtype=author&query=Aschersleben%2C+J">J. Aschersleben</a>, <a href="/search/astro-ph?searchtype=author&query=Ashkar%2C+H">H. Ashkar</a> , et al. (540 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.04857v2-abstract-short" style="display: inline;"> Monochromatic gamma-ray signals constitute a potential smoking gun signature for annihilating or decaying dark matter particles that could relatively easily be distinguished from astrophysical or instrumental backgrounds. We provide an updated assessment of the sensitivity of the Cherenkov Telescope Array (CTA) to such signals, based on observations of the Galactic centre region as well as of sele… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.04857v2-abstract-full').style.display = 'inline'; document.getElementById('2403.04857v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.04857v2-abstract-full" style="display: none;"> Monochromatic gamma-ray signals constitute a potential smoking gun signature for annihilating or decaying dark matter particles that could relatively easily be distinguished from astrophysical or instrumental backgrounds. We provide an updated assessment of the sensitivity of the Cherenkov Telescope Array (CTA) to such signals, based on observations of the Galactic centre region as well as of selected dwarf spheroidal galaxies. We find that current limits and detection prospects for dark matter masses above 300 GeV will be significantly improved, by up to an order of magnitude in the multi-TeV range. This demonstrates that CTA will set a new standard for gamma-ray astronomy also in this respect, as the world's largest and most sensitive high-energy gamma-ray observatory, in particular due to its exquisite energy resolution at TeV energies and the adopted observational strategy focussing on regions with large dark matter densities. Throughout our analysis, we use up-to-date instrument response functions, and we thoroughly model the effect of instrumental systematic uncertainties in our statistical treatment. We further present results for other potential signatures with sharp spectral features, e.g.~box-shaped spectra, that would likewise very clearly point to a particle dark matter origin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.04857v2-abstract-full').style.display = 'none'; document.getElementById('2403.04857v2-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 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">44 pages JCAP style (excluding author list and references), 19 figures; minor changes to match published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> JCAP 07 (2024) 047 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.01941">arXiv:2403.01941</a> <span> [<a href="https://arxiv.org/pdf/2403.01941">pdf</a>, <a href="https://arxiv.org/ps/2403.01941">ps</a>, <a href="https://arxiv.org/format/2403.01941">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/10.1051/0004-6361/202349033">10.1051/0004-6361/202349033 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Probing the emission mechanism and nature of the pulsating compact object in the X-ray binary SAX J1324.4-6200 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ducci%2C+L">L. Ducci</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">E. Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Burgay%2C+M">M. Burgay</a>, <a href="/search/astro-ph?searchtype=author&query=Malacaria%2C+C">C. Malacaria</a>, <a href="/search/astro-ph?searchtype=author&query=Ridolfi%2C+A">A. Ridolfi</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Serim%2C+M+M">M. M. Serim</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Santangelo%2C+A">A. Santangelo</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="2403.01941v1-abstract-short" style="display: inline;"> Recently, there has been renewed interest in the Be X-ray binary (Be/XRB) SAX J1324.4-6200 because of its spatial coincidence with a gamma-ray source detected by Fermi/LAT. To explore more thoroughly its properties, new observations were carried out in 2023 by NuSTAR, XMM-Newton, and Swift, jointly covering the energy range 0.2-79 keV. The X-ray spectrum of SAX J1324.4-6200 fits well with an absor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.01941v1-abstract-full').style.display = 'inline'; document.getElementById('2403.01941v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.01941v1-abstract-full" style="display: none;"> Recently, there has been renewed interest in the Be X-ray binary (Be/XRB) SAX J1324.4-6200 because of its spatial coincidence with a gamma-ray source detected by Fermi/LAT. To explore more thoroughly its properties, new observations were carried out in 2023 by NuSTAR, XMM-Newton, and Swift, jointly covering the energy range 0.2-79 keV. The X-ray spectrum of SAX J1324.4-6200 fits well with an absorbed power law with a high energy cut-off. We measured a NuSTAR spin period of 175.8127 +/- 0.0036 s and an XMM-Newton spin period of 175.862 +/- 0.025 s. All the available spin period measurements of SAX J1324.4-6200, spanning 29 years, are correlated with time, resulting in a remarkably stable spin-down of dP/dt=(6.09 +/- 0.06)*1E-9 s/s. If SAX J1324.4-6200 hosts an accretion powered pulsar, accretion torque models indicate a surface magnetic field of ~1E12-1E13 G. The X-ray properties emerging from our analysis strenghten the hypothesis that SAX J1324.4-6200 belongs to the small group of persistent Be/XRBs. We also performed radio observations with the Parkes Murriyang telescope, to search for radio pulsations. However, no radio pulsations compatible with the rotational ephemeris of SAX J1324.4-6200 were detected. We rule out the hypothesis that SAX J1324.4-6200 is a gamma-ray binary where the emission is produced by interactions between the pulsar and the companion winds. Other models commonly used to account for the production of gamma-rays in accreting pulsars cannot reproduce the bright emission from SAX J1324.4-6200. We examined other mechanisms for the gamma-ray emission and noted that there is a ~0.5% chance probability that an unknown extragalactic AGN observed through the Galactic plane may coincidentally fall within the Fermi/LAT error circle of the source and be the responsible of the gamma-ray emission. [Abridged] <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.01941v1-abstract-full').style.display = 'none'; document.getElementById('2403.01941v1-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 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">Accepted for publication in Astronomy and Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 685, A148 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.07018">arXiv:2402.07018</a> <span> [<a href="https://arxiv.org/pdf/2402.07018">pdf</a>, <a href="https://arxiv.org/format/2402.07018">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Study of solar brightness profiles in the 18-26 GHz frequency range with INAF radio telescopes II. Evidence for coronal emission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Marongiu%2C+M">M. Marongiu</a>, <a href="/search/astro-ph?searchtype=author&query=Pellizzoni%2C+A">A. Pellizzoni</a>, <a href="/search/astro-ph?searchtype=author&query=Righini%2C+S">S. Righini</a>, <a href="/search/astro-ph?searchtype=author&query=Mulas%2C+S">S. Mulas</a>, <a href="/search/astro-ph?searchtype=author&query=Nesti%2C+R">R. Nesti</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">A. Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Serra%2C+G">G. Serra</a>, <a href="/search/astro-ph?searchtype=author&query=Valente%2C+G">G. Valente</a>, <a href="/search/astro-ph?searchtype=author&query=Egron%2C+E">E. Egron</a>, <a href="/search/astro-ph?searchtype=author&query=Murtas%2C+G">G. Murtas</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=Melis%2C+A">A. Melis</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">S. L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Zucca%2C+P">P. Zucca</a>, <a href="/search/astro-ph?searchtype=author&query=Zanichelli%2C+A">A. Zanichelli</a>, <a href="/search/astro-ph?searchtype=author&query=Bachetti%2C+M">M. Bachetti</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Buffa%2C+F">F. Buffa</a>, <a href="/search/astro-ph?searchtype=author&query=Concu%2C+R">R. Concu</a>, <a href="/search/astro-ph?searchtype=author&query=Deiana%2C+G+L">G. L. Deiana</a>, <a href="/search/astro-ph?searchtype=author&query=Karakotia%2C+C">C. Karakotia</a>, <a href="/search/astro-ph?searchtype=author&query=Ladu%2C+A">A. Ladu</a>, <a href="/search/astro-ph?searchtype=author&query=Maccaferri%2C+A">A. Maccaferri</a> , et al. (21 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.07018v1-abstract-short" style="display: inline;"> One of the most important objectives of solar physics is the physical understanding of the solar atmosphere, the structure of which is also described in terms of the density (N) and temperature (T) distributions of the atmospheric matter. Several multi-frequency analyses show that the characteristics of these distributions are still debated, especially for the outer coronal emission. We aim to c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07018v1-abstract-full').style.display = 'inline'; document.getElementById('2402.07018v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.07018v1-abstract-full" style="display: none;"> One of the most important objectives of solar physics is the physical understanding of the solar atmosphere, the structure of which is also described in terms of the density (N) and temperature (T) distributions of the atmospheric matter. Several multi-frequency analyses show that the characteristics of these distributions are still debated, especially for the outer coronal emission. We aim to constrain the T and N distributions of the solar atmosphere through observations in the centimetric radio domain. We employ single-dish observations from two of the INAF radio telescopes at the K-band frequencies (18 - 26 GHz). We investigate the origin of the significant brightness temperature ($T_B$) level that we detected up to the upper corona ($\sim 800$ Mm of altitude with respect to the photospheric solar surface). To probe the physical origin of the atmospheric emission and to constrain instrumental biases, we reproduced the solar signal by convolving specific 2D antenna beam models. The analysis of the solar atmosphere is performed by adopting a physical model that assumes the thermal bremsstrahlung as the emission mechanism, with specific T and N distributions. The modelled $T_B$ profiles are compared with those observed by averaging solar maps obtained during the minimum of solar activity (2018 - 2020). The T and N distributions are compatible (within $25\%$ of uncertainty) with the model up to $\sim 60$ Mm and $\sim 100$ Mm of altitude, respectively. The analysis of the role of the antenna beam pattern on our solar maps proves the physical nature of the atmospheric emission in our images up to the coronal tails seen in our $T_B$ profiles. The challenging analysis of the coronal radio emission at higher altitudes, together with the data from satellite instruments will require further multi-frequency measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07018v1-abstract-full').style.display = 'none'; document.getElementById('2402.07018v1-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, 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">12 pages, 8 figures, 5 tables, accepted by A&A; v1</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.13198">arXiv:2401.13198</a> <span> [<a href="https://arxiv.org/pdf/2401.13198">pdf</a>, <a href="https://arxiv.org/format/2401.13198">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Study of solar brightness profiles in the 18-26 GHz frequency range with INAF radio telescopes I: solar radius </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Marongiu%2C+M">M. Marongiu</a>, <a href="/search/astro-ph?searchtype=author&query=Pellizzoni%2C+A">A. Pellizzoni</a>, <a href="/search/astro-ph?searchtype=author&query=Mulas%2C+S">S. Mulas</a>, <a href="/search/astro-ph?searchtype=author&query=Righini%2C+S">S. Righini</a>, <a href="/search/astro-ph?searchtype=author&query=Nesti%2C+R">R. Nesti</a>, <a href="/search/astro-ph?searchtype=author&query=Murtas%2C+G">G. Murtas</a>, <a href="/search/astro-ph?searchtype=author&query=Egron%2C+E">E. Egron</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=Melis%2C+A">A. Melis</a>, <a href="/search/astro-ph?searchtype=author&query=Valente%2C+G">G. Valente</a>, <a href="/search/astro-ph?searchtype=author&query=Serra%2C+G">G. Serra</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">S. L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Zanichelli%2C+A">A. Zanichelli</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Loru%2C+S">S. Loru</a>, <a href="/search/astro-ph?searchtype=author&query=Bachetti%2C+M">M. Bachetti</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Buffa%2C+F">F. Buffa</a>, <a href="/search/astro-ph?searchtype=author&query=Concu%2C+R">R. Concu</a>, <a href="/search/astro-ph?searchtype=author&query=Deiana%2C+G+L">G. L. Deiana</a>, <a href="/search/astro-ph?searchtype=author&query=Karakotia%2C+C">C. Karakotia</a>, <a href="/search/astro-ph?searchtype=author&query=Ladu%2C+A">A. Ladu</a>, <a href="/search/astro-ph?searchtype=author&query=Maccaferri%2C+A">A. Maccaferri</a>, <a href="/search/astro-ph?searchtype=author&query=Marongiu%2C+P">P. Marongiu</a>, <a href="/search/astro-ph?searchtype=author&query=Messerotti%2C+M">M. Messerotti</a> , et al. (10 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="2401.13198v1-abstract-short" style="display: inline;"> The Sun is an extraordinary workbench, from which several fundamental astronomical parameters can be measured with high precision. Among these parameters, the solar radius $R_{\odot}$ plays an important role in several aspects, such as in evolutionary models. Despite the efforts in obtaining accurate measurements of $R_{\odot}$, the subject is still debated and measurements are puzzling and/or lac… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.13198v1-abstract-full').style.display = 'inline'; document.getElementById('2401.13198v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.13198v1-abstract-full" style="display: none;"> The Sun is an extraordinary workbench, from which several fundamental astronomical parameters can be measured with high precision. Among these parameters, the solar radius $R_{\odot}$ plays an important role in several aspects, such as in evolutionary models. Despite the efforts in obtaining accurate measurements of $R_{\odot}$, the subject is still debated and measurements are puzzling and/or lacking in many frequency ranges. We aimed to determine the mean, equatorial, and polar radii of the Sun ($R_c$, $R_{eq}$, and $R_{pol}$) in the frequency range 18.1 - 26.1 GHz. We employed single-dish observations from the newly-appointed Medicina "Gavril Grueff" Radio Telescope and the Sardinia Radio Telescope (SRT) throughout 5 years, from 2018 to mid-2023, in the framework of the SunDish project for solar monitoring. Two methods to calculate the radius at radio frequencies are considered and compared. To assess the quality of our radius determinations, we also analysed the possible degrading effects of the antenna beam pattern on our solar maps, using two 2D-models. We carried out a correlation analysis with the evolution of the solar cycle through the calculation of Pearson's correlation coefficient $蟻$. We obtained several values for the solar radius - ranging between 959 and 994 arcsec - and $蟻$, with typical errors of a few arcsec. Our $R_{\odot}$ measurements, consistent with values reported in literature, suggest a weak prolatness of the solar limb ($R_{eq}$ > $R_{pol}$), although $R_{eq}$ and $R_{pol}$ are statistically compatible within 3$蟽$ errors. The correlation analysis using the solar images from Grueff shows (1) a positive correlation between the solar activity and the temporal variation of $R_c$ (and $R_{eq}$) at all observing frequencies, and (2) a weak anti-correlation between the temporal variation of $R_{pol}$ and the solar activity at 25.8 GHz. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.13198v1-abstract-full').style.display = 'none'; document.getElementById('2401.13198v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 12 figures, 6 tables, accepted by A&A; v1</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.03289">arXiv:2401.03289</a> <span> [<a href="https://arxiv.org/pdf/2401.03289">pdf</a>, <a href="https://arxiv.org/ps/2401.03289">ps</a>, <a href="https://arxiv.org/format/2401.03289">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> <p class="title is-5 mathjax"> NuSTAR and Swift observations of two supergiant fast X-ray transients: AX J1841.0-0536 and SAX J1818.6-1703 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">E. Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">C. Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.03289v1-abstract-short" style="display: inline;"> Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact object magnetic field is generally considered a key parameter to discriminate among possible scenarios. We present here the analysis of two simultaneous observ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.03289v1-abstract-full').style.display = 'inline'; document.getElementById('2401.03289v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.03289v1-abstract-full" style="display: none;"> Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact object magnetic field is generally considered a key parameter to discriminate among possible scenarios. We present here the analysis of two simultaneous observational campaigns carried out with Swift and NuSTAR targeting the supergiant fast X-ray transient sources AX J1841.0-0536 and SAX J1818.6-1703. A detailed spectral analysis is presented for both sources, with the main goal of hunting for cyclotron resonant scattering features that can provide a direct measurement of the neutron star magnetic field intensity. AX J1841.0-0536 was caught during the observational campaign at a relatively low flux. The source broad-band spectrum was featureless and could be well described by using a combination of a hot blackbody and a power-law component with no measurable cut-off energy. In the case of SAX J1818.6-1703, the broad-band spectrum presented a relatively complex curvature which could be described by an absorbed cut-off power-law (including both a cut-off and a folding energy) and featured a prominent edge at $\sim$7 keV, compatible with being associated to the presence of a "screen" of neutral material partly obscuring the X-ray source. The fit to the broad-band spectrum also required the addition of a moderately broad ($\sim$1.6 keV) feature centered at $\sim$14 keV. If interpreted as a cyclotron resonant scattering feature, our results would indicate for SAX J1818.6-1703 a relatively low magnetized neutron star ($\sim$1.2$\times$10$^{12}$ G). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.03289v1-abstract-full').style.display = 'none'; document.getElementById('2401.03289v1-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">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/2312.09172">arXiv:2312.09172</a> <span> [<a href="https://arxiv.org/pdf/2312.09172">pdf</a>, <a href="https://arxiv.org/ps/2312.09172">ps</a>, <a href="https://arxiv.org/format/2312.09172">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> <p class="title is-5 mathjax"> Swift/XRT observations of superorbital modulations in wind-fed supergiant X-ray binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">E. Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Islam%2C+N">N. Islam</a>, <a href="/search/astro-ph?searchtype=author&query=Corbet%2C+R+H+D">R. H. D. Corbet</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2312.09172v1-abstract-short" style="display: inline;"> We present the first Swift/XRT long-term monitoring of 2S 0114+650, a wind-fed supergiant X-ray binary for which both orbital and superorbital periods are known (P_orb~11.6d and P_sup~0.8d). Our campaign, summing up to ~ 79ks, is the most intense and complete sampling of the X-ray light curve of this source with a sensitive pointed X-ray instrument, and covers 17 orbital, and 6 superorbital cycles… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.09172v1-abstract-full').style.display = 'inline'; document.getElementById('2312.09172v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.09172v1-abstract-full" style="display: none;"> We present the first Swift/XRT long-term monitoring of 2S 0114+650, a wind-fed supergiant X-ray binary for which both orbital and superorbital periods are known (P_orb~11.6d and P_sup~0.8d). Our campaign, summing up to ~ 79ks, is the most intense and complete sampling of the X-ray light curve of this source with a sensitive pointed X-ray instrument, and covers 17 orbital, and 6 superorbital cycles. The combination of flexibility, sensitivity, and soft X-ray coverage of XRT allowed us to confirm previously reported spectral changes along the orbital cycle of the source and unveil the variability in its spectral parameters as a function of the superorbital phase. For completeness, we also report on a similar analysis carried out by exploiting XRT archival data on three additional wind-fed supergiant X-ray binaries IGR J16418-4532, IGR J16479-4514, and IGR J16493-4348. For these sources, the archival data provided coverage along several superorbital cycles but our analysis could not reveal any significant spectral variability. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.09172v1-abstract-full').style.display = 'none'; document.getElementById('2312.09172v1-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 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 Monthly Notices of the Royal Astronomical Society. 17 pages, 7 tables, 5 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/2312.01899">arXiv:2312.01899</a> <span> [<a href="https://arxiv.org/pdf/2312.01899">pdf</a>, <a href="https://arxiv.org/format/2312.01899">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Eruptive events with exceptionally bright emission in HI Ly-alpha observed by the Metis coronagraph </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Russano%2C+G">G. Russano</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">L. Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S">S. Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=%C4%8D%2C+S+J+%C4%8D">S. Jej 膷i 膷</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">A. Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">G. E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S">S. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">G. Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">A. Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Zangrilli%2C+L">L. Zangrilli</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a> , et al. (7 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="2312.01899v1-abstract-short" style="display: inline;"> Metis, the coronagraph on board Solar Orbiter, provides for the first time coronagraphic imaging in the ultraviolet HI Ly-alpha line and, simultaneously, in polarized visible light, thus providing a host of information on the properties of CMEs and solar eruptions like their overall dynamics, time evolution, mass content, and outflow propagation velocity in the expanding corona. We analyzed in thi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.01899v1-abstract-full').style.display = 'inline'; document.getElementById('2312.01899v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.01899v1-abstract-full" style="display: none;"> Metis, the coronagraph on board Solar Orbiter, provides for the first time coronagraphic imaging in the ultraviolet HI Ly-alpha line and, simultaneously, in polarized visible light, thus providing a host of information on the properties of CMEs and solar eruptions like their overall dynamics, time evolution, mass content, and outflow propagation velocity in the expanding corona. We analyzed in this work six CMEs observed by Metis between April and October 2021, which are characterized by a very strong HI Ly-alpha emission. We studied in particular the morphology, kinematics, and the temporal and radial evolution of the emission of such events, focusing on the brightest UV features. The kinematics of the eruptive events under consideration were studied by determining the height-time profiles of the brightest parts on the Metis plane of the sky. Furthermore, the 3D position in the heliosphere of the CMEs were determined by employing co-temporal images from two other coronagraphs: LASCO/C2 onboard SOHO, and COR2 onboard STEREO-A. Finally, the radiometrically calibrated Metis images of the bright UV features were analyzed to provide estimates of their volume and density. From the kinematics and radiometric analyses, we obtained indications of the temperatures of the bright UV cores of these events. The analysis of these strong UV-emitting features associated with coronal mass ejections demonstrates the capabilities of the current constellation of space coronagraphs, Metis, LASCO/C2, and COR2, in providing a complete characterization of the structure and dynamics of eruptive events in their propagation phase from their inception up to several solar radii. Furthermore, we show how the unique capabilities of the Metis instrument to observe these events in both HI Ly-alpha line and polarized VL radiation allow plasma diagnostics on the thermal state of these events. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.01899v1-abstract-full').style.display = 'none'; document.getElementById('2312.01899v1-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 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">26 pages, 26 figures, 2 appendices</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">MSC Class:</span> 85-02 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.07197">arXiv:2311.07197</a> <span> [<a href="https://arxiv.org/pdf/2311.07197">pdf</a>, <a href="https://arxiv.org/ps/2311.07197">ps</a>, <a href="https://arxiv.org/format/2311.07197">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> <p class="title is-5 mathjax"> Swift, NuSTAR, and INTEGRAL observations of the symbiotic X-ray binary IGR J16194-2810 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">E. Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">C. Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Ducci%2C+L">L. Ducci</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.07197v1-abstract-short" style="display: inline;"> We report on a simultaneous observational campaign with both Swift/XRT and NuSTAR targeting the symbiotic X-ray binary IGR J16194-2810. The main goal of the campaign was to investigate the possible presence of cyclotron scattering absorption features in the broad-band spectrum of the source, and help advance our understanding of the process of neutron star formation via the accretion-induced colla… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.07197v1-abstract-full').style.display = 'inline'; document.getElementById('2311.07197v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.07197v1-abstract-full" style="display: none;"> We report on a simultaneous observational campaign with both Swift/XRT and NuSTAR targeting the symbiotic X-ray binary IGR J16194-2810. The main goal of the campaign was to investigate the possible presence of cyclotron scattering absorption features in the broad-band spectrum of the source, and help advance our understanding of the process of neutron star formation via the accretion-induced collapse of a white dwarf. The 1-30 keV spectrum of the source, as measured during our campaign, did not reveal the presence of any statistically significant absorption feature. The spectrum could be well described using a model comprising a thermal black-body hot component, most likely emerging from the surface of the accreting neutron star, and a power-law with no measurable cut-off energy (and affected by a modest absorption column density). Compared to previous analyses in the literature, we could rule out the presence of a colder thermal component emerging from an accretion disk, compatible with the idea that IGR J16194-2810 is a wind-fed binary (as most of the symbiotic X-ray binaries). Our results were strengthened by exploiting the archival XRT and INTEGRAL data, extending the validity of the spectral model used up to 0.3-40 keV and demonstrating that IGR J16194-2810 is unlikely to undergo significant spectral variability over time in the X-ray domain. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.07197v1-abstract-full').style.display = 'none'; document.getElementById('2311.07197v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">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/2310.07413">arXiv:2310.07413</a> <span> [<a href="https://arxiv.org/pdf/2310.07413">pdf</a>, <a href="https://arxiv.org/format/2310.07413">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> <p class="title is-5 mathjax"> Chasing Gravitational Waves with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Green%2C+J+G">Jarred Gershon Green</a>, <a href="/search/astro-ph?searchtype=author&query=Carosi%2C+A">Alessandro Carosi</a>, <a href="/search/astro-ph?searchtype=author&query=Nava%2C+L">Lara Nava</a>, <a href="/search/astro-ph?searchtype=author&query=Patricelli%2C+B">Barbara Patricelli</a>, <a href="/search/astro-ph?searchtype=author&query=Sch%C3%BCssler%2C+F">Fabian Sch眉ssler</a>, <a href="/search/astro-ph?searchtype=author&query=Seglar-Arroyo%2C+M">Monica Seglar-Arroyo</a>, <a href="/search/astro-ph?searchtype=author&query=Consortium%2C+C">Cta Consortium</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+K">Kazuki Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+S">Shotaro Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Acharyya%2C+A">Atreya Acharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Adam%2C+R">Remi Adam</a>, <a href="/search/astro-ph?searchtype=author&query=Aguasca-Cabot%2C+A">Arnau Aguasca-Cabot</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">Ivan Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+J">Jorge Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alvarez-Crespo%2C+N">Nuria Alvarez-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">Rafael Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amans%2C+J">Jean-Philippe Amans</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">Elena Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Ambrosino%2C+F">Filippo Ambrosino</a>, <a href="/search/astro-ph?searchtype=author&query=Ang%C3%BCner%2C+E+O">Ekrem Oguzhan Ang眉ner</a>, <a href="/search/astro-ph?searchtype=author&query=Antonelli%2C+L+A">Lucio Angelo Antonelli</a>, <a href="/search/astro-ph?searchtype=author&query=Aramo%2C+C">Carla Aramo</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">Cornelia Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Arrabito%2C+L">Luisa Arrabito</a> , et al. (545 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="2310.07413v3-abstract-short" style="display: inline;"> The detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.07413v3-abstract-full').style.display = 'inline'; document.getElementById('2310.07413v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.07413v3-abstract-full" style="display: none;"> The detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a gravitational wave signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. New observing modes and follow-up strategies are being developed for CTA to rapidly cover localization areas of gravitational wave events that are typically larger than the CTA field of view. This work will evaluate and provide estimations on the expected number of of gravitational wave events that will be observable with CTA, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.07413v3-abstract-full').style.display = 'none'; document.getElementById('2310.07413v3-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 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">Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> CTA-ICRC/2023/30 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.11186">arXiv:2309.11186</a> <span> [<a href="https://arxiv.org/pdf/2309.11186">pdf</a>, <a href="https://arxiv.org/ps/2309.11186">ps</a>, <a href="https://arxiv.org/format/2309.11186">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Observations of the chromospheric Evershed flow of sunspot penumbra </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Schillir%C3%B2%2C+F">Francesco Schillir貌</a>, <a href="/search/astro-ph?searchtype=author&query=Falco%2C+M">Mariachiara Falco</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.11186v1-abstract-short" style="display: inline;"> The sunspot penumbra is usually observed in the photosphere and it is of particular interest for its magneto-convection which seems to transport the heat from the top of the convection zone into the solar atmosphere. It is well known that the penumbra magnetic field extends in the upper layers of the solar atmosphere forming the so called super-penumbra. Thanks to the application of the Self Organ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.11186v1-abstract-full').style.display = 'inline'; document.getElementById('2309.11186v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.11186v1-abstract-full" style="display: none;"> The sunspot penumbra is usually observed in the photosphere and it is of particular interest for its magneto-convection which seems to transport the heat from the top of the convection zone into the solar atmosphere. It is well known that the penumbra magnetic field extends in the upper layers of the solar atmosphere forming the so called super-penumbra. Thanks to the application of the Self Organizing Map technique to a spectral dataset containing monochromatic images acquired along the Ca II 854.2 nm and H$伪$ 656.28 nm lines, we were able to segment the penumbra and to measure the plasma velocity along the chromospheric portions of penumbral filaments. We found that the head, body and tail of penumbral filaments show vertical flows compatible with the persistence of the Evershed flow. Instead, the inverse Evershed flow has been observed only in the outer portion of the super-penumbra. We found that two opposite Evershed regimes work next to each other, without overlapping and both contribute to the downflow around sunspots. These results confirm the uncombed model of the sunspot penumbra and provide some hints that the downflow around sunspots may be ascribed to the magnetic field dragging the plasma down. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.11186v1-abstract-full').style.display = 'none'; document.getElementById('2309.11186v1-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.09615">arXiv:2309.09615</a> <span> [<a href="https://arxiv.org/pdf/2309.09615">pdf</a>, <a href="https://arxiv.org/format/2309.09615">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> <p class="title is-5 mathjax"> Bright blazar flares with CTA </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Finke%2C+J">J. Finke</a>, <a href="/search/astro-ph?searchtype=author&query=Grolleron%2C+G">G. Grolleron</a>, <a href="/search/astro-ph?searchtype=author&query=Lenain%2C+J+P">J. P. Lenain</a>, <a href="/search/astro-ph?searchtype=author&query=Hovatta%2C+T">T. Hovatta</a>, <a href="/search/astro-ph?searchtype=author&query=Joshi%2C+M">M. Joshi</a>, <a href="/search/astro-ph?searchtype=author&query=Lindfors%2C+E">E. Lindfors</a>, <a href="/search/astro-ph?searchtype=author&query=Morris%2C+P">P. Morris</a>, <a href="/search/astro-ph?searchtype=author&query=Petropoulou%2C+M">M. Petropoulou</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Zacharias%2C+M">M. Zacharias</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.09615v1-abstract-short" style="display: inline;"> The TeV extragalactic sky is dominated by blazars, radio-loud active galactic nuclei with a relativistic jet pointing towards the Earth. Blazars show variability that can be quite exceptional both in terms of flux (orders of magnitude of brightening) and time (down to the minute timescale). This bright flaring activity contains key information on the physics of particle acceleration and photon pro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09615v1-abstract-full').style.display = 'inline'; document.getElementById('2309.09615v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.09615v1-abstract-full" style="display: none;"> The TeV extragalactic sky is dominated by blazars, radio-loud active galactic nuclei with a relativistic jet pointing towards the Earth. Blazars show variability that can be quite exceptional both in terms of flux (orders of magnitude of brightening) and time (down to the minute timescale). This bright flaring activity contains key information on the physics of particle acceleration and photon production in the emitting region, as well as the structure and physical properties of the jet itself. The TeV band is accessed from the ground by Cherenkov telescopes that image the pair cascade triggered by the interaction of the gamma ray with the Earth's atmosphere. The Cherenkov Telescope Array (CTA) represents the upcoming generation of imaging atmospheric Cherenkov telescopes, with a significantly higher sensitivity and larger energy coverage with respect to current instruments. It will thus provide us with unprecedented statistics on blazar light-curves and spectra. In this contribution we present the results from realistic simulations of CTA observations of bright blazar flares, taking as input state-of-the-art numerical simulations of blazar emission models and including all relevant observational constraints. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09615v1-abstract-full').style.display = 'none'; document.getElementById('2309.09615v1-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> CTA-ICRC/2023/27 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.09591">arXiv:2309.09591</a> <span> [<a href="https://arxiv.org/pdf/2309.09591">pdf</a>, <a href="https://arxiv.org/format/2309.09591">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/10.1051/0004-6361/202347536">10.1051/0004-6361/202347536 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Analysis of full-disc H alpha observations: Carrington maps and filament properties in 1909-2022 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chatzistergos%2C+T">Theodosios Chatzistergos</a>, <a href="/search/astro-ph?searchtype=author&query=Ermolli%2C+I">Ilaria Ermolli</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+D">Dipankar Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Barata%2C+T">Teresa Barata</a>, <a href="/search/astro-ph?searchtype=author&query=Chouinavas%2C+I">Ioannis Chouinavas</a>, <a href="/search/astro-ph?searchtype=author&query=Falco%2C+M">Mariachiara Falco</a>, <a href="/search/astro-ph?searchtype=author&query=Gafeira%2C+R">Ricardo Gafeira</a>, <a href="/search/astro-ph?searchtype=author&query=Giorgi%2C+F">Fabrizio Giorgi</a>, <a href="/search/astro-ph?searchtype=author&query=Hanaoka%2C+Y">Yoichiro Hanaoka</a>, <a href="/search/astro-ph?searchtype=author&query=Krivova%2C+N+A">Natalie A. Krivova</a>, <a href="/search/astro-ph?searchtype=author&query=Korokhin%2C+V+V">Viktor V. Korokhin</a>, <a href="/search/astro-ph?searchtype=author&query=Louren%C3%A7o%2C+A">Ana Louren莽o</a>, <a href="/search/astro-ph?searchtype=author&query=Marchenko%2C+G+P">Gennady P. Marchenko</a>, <a href="/search/astro-ph?searchtype=author&query=Malherbe%2C+J">Jean-Marie Malherbe</a>, <a href="/search/astro-ph?searchtype=author&query=Peixinho%2C+N">Nuno Peixinho</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sakurai%2C+T">Takashi Sakurai</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.09591v3-abstract-short" style="display: inline;"> Full disc observations of the Sun in the H$伪$ line provide information about the solar chromosphere and in particular about the filaments, which are dark and elongated features that lie along magnetic field polarity inversion lines. This makes them important for studies of solar magnetism. Since full disc H$伪$ observations have been performed at various sites since 1800s, with regular photographic… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09591v3-abstract-full').style.display = 'inline'; document.getElementById('2309.09591v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.09591v3-abstract-full" style="display: none;"> Full disc observations of the Sun in the H$伪$ line provide information about the solar chromosphere and in particular about the filaments, which are dark and elongated features that lie along magnetic field polarity inversion lines. This makes them important for studies of solar magnetism. Since full disc H$伪$ observations have been performed at various sites since 1800s, with regular photographic data having started in the beginning of the 20th century, they are an invaluable source of information on past solar magnetism. In this work we aimed at deriving accurate information about filaments from historical and modern full disc H$伪$ observations. We have consistently processed observations from 15 H$伪$ archives spanning 1909-2022. Our data processing includes photometric calibration of the data stored on photographic plates. We have constructed also Carrington maps from the calibrated H$伪$ images. We find that filament areas are affected by the bandwidth of the observation. Thus, cross-calibration of the filament areas derived from different archives is needed. We have produced a composite of filament areas from individual archives by scaling all of them to the Meudon series. Our composite butterfly diagram shows very distinctly the common features of filament evolution, that is the poleward migration as well as a decrease in the mean latitude of filaments as the cycle progresses. We also find that during activity maxima, filaments on average cover about 1% of the solar surface. We see only a weak change in the amplitude of cycles in filament areas, in contrast to sunspot and plage areas. Analysis of H$伪$ data for archives with contemporaneous Ca II K observations allowed us to identify and verify archive inconsistencies, which will also have implications for reconstructions of past solar magnetism and irradiance from Ca II K data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09591v3-abstract-full').style.display = 'none'; document.getElementById('2309.09591v3-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 14 figures, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 680, A15 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.03712">arXiv:2309.03712</a> <span> [<a href="https://arxiv.org/pdf/2309.03712">pdf</a>, <a href="https://arxiv.org/format/2309.03712">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</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/10.1088/1475-7516/2024/10/004">10.1088/1475-7516/2024/10/004 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Prospects for $纬$-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Consortium%2C+T+C+T+A">The Cherenkov Telescope Array Consortium</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+K">K. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+S">S. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Acero%2C+F">F. Acero</a>, <a href="/search/astro-ph?searchtype=author&query=Acharyya%2C+A">A. Acharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Adam%2C+R">R. Adam</a>, <a href="/search/astro-ph?searchtype=author&query=Aguasca-Cabot%2C+A">A. Aguasca-Cabot</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Aguirre-Santaella%2C+A">A. Aguirre-Santaella</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+J">J. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+R">R. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alvarez-Crespo%2C+N">N. Alvarez-Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amans%2C+J+-">J. -P. Amans</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Ang%C3%BCner%2C+E+O">E. O. Ang眉ner</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=Aramo%2C+C">C. Aramo</a>, <a href="/search/astro-ph?searchtype=author&query=Araya%2C+M">M. Araya</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Arrabito%2C+L">L. Arrabito</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+K">K. Asano</a>, <a href="/search/astro-ph?searchtype=author&query=Ascas%C3%ADbar%2C+Y">Y. Ascas铆bar</a>, <a href="/search/astro-ph?searchtype=author&query=Aschersleben%2C+J">J. Aschersleben</a> , et al. (542 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="2309.03712v1-abstract-short" style="display: inline;"> Galaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at gamma-ray energies and are predicted to be sources of large-scale gamma-ray emission due to hadronic interactions in the intracluster med… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.03712v1-abstract-full').style.display = 'inline'; document.getElementById('2309.03712v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.03712v1-abstract-full" style="display: none;"> Galaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at gamma-ray energies and are predicted to be sources of large-scale gamma-ray emission due to hadronic interactions in the intracluster medium. We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. We perform a detailed spatial and spectral modelling of the expected signal for the DM and the CRp components. For each, we compute the expected CTA sensitivity. The observing strategy of Perseus is also discussed. In the absence of a diffuse signal (non-detection), CTA should constrain the CRp to thermal energy ratio within the radius $R_{500}$ down to about $X_{500}<3\times 10^{-3}$, for a spatial CRp distribution that follows the thermal gas and a CRp spectral index $伪_{\rm CRp}=2.3$. Under the optimistic assumption of a pure hadronic origin of the Perseus radio mini-halo and depending on the assumed magnetic field profile, CTA should measure $伪_{\rm CRp}$ down to about $螖伪_{\rm CRp}\simeq 0.1$ and the CRp spatial distribution with 10% precision. Regarding DM, CTA should improve the current ground-based gamma-ray DM limits from clusters observations on the velocity-averaged annihilation cross-section by a factor of up to $\sim 5$, depending on the modelling of DM halo substructure. In the case of decay of DM particles, CTA will explore a new region of the parameter space, reaching models with $蟿_蠂>10^{27}$s for DM masses above 1 TeV. These constraints will provide unprecedented sensitivity to the physics of both CRp acceleration and transport at cluster scale and to TeV DM particle models, especially in the decay scenario. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.03712v1-abstract-full').style.display = 'none'; document.getElementById('2309.03712v1-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">93 pages (including author list, appendix and references), 143 figures. Submitted to JCAP</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> JCAP10(2024)004 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.06061">arXiv:2308.06061</a> <span> [<a href="https://arxiv.org/pdf/2308.06061">pdf</a>, <a href="https://arxiv.org/format/2308.06061">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> <p class="title is-5 mathjax"> Modelling the expected very high energy gamma-ray emission from accreting neutron stars in X-ray binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ducci%2C+L">L. Ducci</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Santangelo%2C+A">A. Santangelo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.06061v1-abstract-short" style="display: inline;"> The detection of gamma-ray emission from accreting pulsars in X-ray binaries (XRBs) has long been sought after. For some high-mass X-ray binaries (HMXBs), marginal detections have recently been reported. Regardless of whether these will be confirmed or not, future telescopes operating in the gamma-ray band could offer the sensitivity needed to achieve solid detections and possibly spectra. In view… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.06061v1-abstract-full').style.display = 'inline'; document.getElementById('2308.06061v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.06061v1-abstract-full" style="display: none;"> The detection of gamma-ray emission from accreting pulsars in X-ray binaries (XRBs) has long been sought after. For some high-mass X-ray binaries (HMXBs), marginal detections have recently been reported. Regardless of whether these will be confirmed or not, future telescopes operating in the gamma-ray band could offer the sensitivity needed to achieve solid detections and possibly spectra. In view of future observational advances, we explored the expected emission above 10 GeV from XRBs, based on the Cheng & Ruderman model, where gamma-ray photons are produced by the decay of pion-0 originated by protons accelerated in the magnetosphere of an accreting pulsar fed by an accretion disc. We improved this model by considering, through Monte Carlo simulations, the development of cascades inside of and outside the accretion disc, taking into account pair and photon production processes that involve interaction with nuclei, X-ray photons from the accretion disc, and the magnetic field. We produced grids of solutions for different input parameter values of the X-ray luminosity (L_x), magnetic field strength (B), and for different properties of the region where acceleration occurs. We found that the gamma-ray luminosity spans more than five orders of magnitude, with a maximum of ~1E35 erg/s. The gamma-ray spectra show a large variety of shapes: some have most of the emission below ~100 GeV, others are harder (emission up to 10-100 TeV). We compared our results with Fermi/LAT and VERITAS detections and upper-limits of two HMXBs: A0535+26 and GROJ1008-57. More consequential comparisons will be possible when more sensitive instruments will be operational in the coming years. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.06061v1-abstract-full').style.display = 'none'; document.getElementById('2308.06061v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">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/2306.10819">arXiv:2306.10819</a> <span> [<a href="https://arxiv.org/pdf/2306.10819">pdf</a>, <a href="https://arxiv.org/format/2306.10819">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="Space Physics">physics.space-ph</span> </div> </div> <p class="title is-5 mathjax"> Coronal Heating Rate in the Slow Solar Wind </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Velli%2C+M">Marco Velli</a>, <a href="/search/astro-ph?searchtype=author&query=Zank%2C+G+P">Gary P. Zank</a>, <a href="/search/astro-ph?searchtype=author&query=Adhikari%2C+L">Laxman Adhikari</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">Cooper Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">Aleksandr Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+L">Lingling Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">Alessandro Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Shi%2C+C">Chen Shi</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Yara De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">Lucia Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">Federica Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">Giovanna Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">Federico Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">Gianalfredo Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">Maurizio Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Russano%2C+G">Giuliana Russano</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">Clementina Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">Vania Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Grimani%2C+C">Catia Grimani</a> , et al. (37 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.10819v1-abstract-short" style="display: inline;"> This Letter reports the first observational estimate of the heating rate in the slowly expanding solar corona. The analysis exploits the simultaneous remote and local observations of the same coronal plasma volume with the Solar Orbiter/Metis and the Parker Solar Probe instruments, respectively, and relies on the basic solar wind magnetohydrodynamic equations. As expected, energy losses are a mino… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10819v1-abstract-full').style.display = 'inline'; document.getElementById('2306.10819v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.10819v1-abstract-full" style="display: none;"> This Letter reports the first observational estimate of the heating rate in the slowly expanding solar corona. The analysis exploits the simultaneous remote and local observations of the same coronal plasma volume with the Solar Orbiter/Metis and the Parker Solar Probe instruments, respectively, and relies on the basic solar wind magnetohydrodynamic equations. As expected, energy losses are a minor fraction of the solar wind energy flux, since most of the energy dissipation that feeds the heating and acceleration of the coronal flow occurs much closer to the Sun than the heights probed in the present study, which range from 6.3 to 13.3 solar radii. The energy deposited to the supersonic wind is then used to explain the observed slight residual wind acceleration and to maintain the plasma in a non-adiabatic state. As derived in the Wentzel-Kramers-Brillouin limit, the present energy transfer rate estimates provide a lower limit, which can be very useful in refining the turbulence-based modeling of coronal heating and subsequent solar wind acceleration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10819v1-abstract-full').style.display = 'none'; document.getElementById('2306.10819v1-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> 19 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.07068">arXiv:2305.07068</a> <span> [<a href="https://arxiv.org/pdf/2305.07068">pdf</a>, <a href="https://arxiv.org/ps/2305.07068">ps</a>, <a href="https://arxiv.org/format/2305.07068">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/10.3847/1538-4357/acd541">10.3847/1538-4357/acd541 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Drop in the hard pulsed fraction and a candidate cyclotron line in IGR J16320-4751 seen by NuSTAR </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bodaghee%2C+A">Arash Bodaghee</a>, <a href="/search/astro-ph?searchtype=author&query=Chiu%2C+A+J+-">Alan J. -L. Chiu</a>, <a href="/search/astro-ph?searchtype=author&query=Tomsick%2C+J+A">John A. Tomsick</a>, <a href="/search/astro-ph?searchtype=author&query=Bhalerao%2C+V">Varun Bhalerao</a>, <a href="/search/astro-ph?searchtype=author&query=Bottacini%2C+E">Eugenio Bottacini</a>, <a href="/search/astro-ph?searchtype=author&query=Clavel%2C+M">Maica Clavel</a>, <a href="/search/astro-ph?searchtype=author&query=Cox%2C+C">Cody Cox</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%BCrst%2C+F">Felix F眉rst</a>, <a href="/search/astro-ph?searchtype=author&query=Middleton%2C+M+J">Matthew J. Middleton</a>, <a href="/search/astro-ph?searchtype=author&query=Rahoui%2C+F">Farid Rahoui</a>, <a href="/search/astro-ph?searchtype=author&query=Rodriguez%2C+J">Jerome Rodriguez</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Pat Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Wilms%2C+J">Joern Wilms</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="2305.07068v1-abstract-short" style="display: inline;"> We report on a timing and spectral analysis of a 50-ks NuSTAR observation of IGR J16320-4751 (= AX J1631.9-4752); a high-mass X-ray binary hosting a slowly-rotating neutron star. In this observation from 2015, the spin period was 1,308.8+/-0.4 s giving a period derivative dP/dt ~ 2E-8 s s-1 when compared with the period measured in 2004. In addition, the pulsed fraction decreased as a function of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07068v1-abstract-full').style.display = 'inline'; document.getElementById('2305.07068v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.07068v1-abstract-full" style="display: none;"> We report on a timing and spectral analysis of a 50-ks NuSTAR observation of IGR J16320-4751 (= AX J1631.9-4752); a high-mass X-ray binary hosting a slowly-rotating neutron star. In this observation from 2015, the spin period was 1,308.8+/-0.4 s giving a period derivative dP/dt ~ 2E-8 s s-1 when compared with the period measured in 2004. In addition, the pulsed fraction decreased as a function of energy, as opposed to the constant trend that was seen previously. This suggests a change in the accretion geometry of the system during the intervening 11 years. The phase-averaged spectra were fit with the typical model for accreting pulsars: a power law with an exponential cutoff. This left positive residuals at 6.4 keV attributable to the known iron K-alpha line, as well as negative residuals around 14 keV from a candidate cyclotron line detected at a significance of 5-sigma. We found no significant differences in the spectral parameters across the spin period, other than the expected changes in flux and component normalizations. A flare lasting around 5 ks was captured during the first half of the observation where the X-ray emission hardened and the local column density decreased. Finally, the binary orbital period was refined to 8.9912+/-0.0078 d thanks to Swift/BAT monitoring data from 2005-2022. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07068v1-abstract-full').style.display = 'none'; document.getElementById('2305.07068v1-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 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">17 pages, 11 figures, Referee-revised version accepted for publication in the Astrophysical Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.14208">arXiv:2304.14208</a> <span> [<a href="https://arxiv.org/pdf/2304.14208">pdf</a>, <a href="https://arxiv.org/format/2304.14208">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> <p class="title is-5 mathjax"> Probing AGN variability with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a>, <a href="/search/astro-ph?searchtype=author&query=Hovatta%2C+T">T. Hovatta</a>, <a href="/search/astro-ph?searchtype=author&query=Lindfors%2C+E">E. Lindfors</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Becerra-Gonzalez%2C+J">J. Becerra-Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Biteau%2C+J">J. Biteau</a>, <a href="/search/astro-ph?searchtype=author&query=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%B6ttcher%2C+M">M. B枚ttcher</a>, <a href="/search/astro-ph?searchtype=author&query=Pino%2C+E+d+G+D">E. de Gouveia Dal Pino</a>, <a href="/search/astro-ph?searchtype=author&query=Dorner%2C+D">D. Dorner</a>, <a href="/search/astro-ph?searchtype=author&query=Grolleron%2C+G">G. Grolleron</a>, <a href="/search/astro-ph?searchtype=author&query=Lenain%2C+J+-">J. -P. Lenain</a>, <a href="/search/astro-ph?searchtype=author&query=Manganaro%2C+M">M. Manganaro</a>, <a href="/search/astro-ph?searchtype=author&query=Max-Moerbeck%2C+W">W. Max-Moerbeck</a>, <a href="/search/astro-ph?searchtype=author&query=Morris%2C+P">P. Morris</a>, <a href="/search/astro-ph?searchtype=author&query=Nilsson%2C+K">K. Nilsson</a>, <a href="/search/astro-ph?searchtype=author&query=Reis%2C+L+P">L. Passos Reis</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sergijenko%2C+O">O. Sergijenko</a>, <a href="/search/astro-ph?searchtype=author&query=Tavecchio%2C+F">F. Tavecchio</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Wagner%2C+S">S. Wagner</a>, <a href="/search/astro-ph?searchtype=author&query=Zacharias%2C+M">M. Zacharias</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.14208v1-abstract-short" style="display: inline;"> Relativistic jets launched by Active Galactic Nuclei are among the most powerful particle accelerators in the Universe. The emission over the entire electromagnetic spectrum of these relativistic jets can be extremely variable with scales of variability from less than few minutes up to several years. These variability patterns, which can be very complex, contain information about the acceleration… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.14208v1-abstract-full').style.display = 'inline'; document.getElementById('2304.14208v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.14208v1-abstract-full" style="display: none;"> Relativistic jets launched by Active Galactic Nuclei are among the most powerful particle accelerators in the Universe. The emission over the entire electromagnetic spectrum of these relativistic jets can be extremely variable with scales of variability from less than few minutes up to several years. These variability patterns, which can be very complex, contain information about the acceleration processes of the particles and the area(s) of emission. Thanks to its sensitivity, five-to twenty-times better than the current generation of Imaging Atmospheric Cherenkov Telescopes depending on energy, the Cherenkov Telescope Array will be able to follow the emission from these objects with a very accurate time sampling and over a wide spectral coverage from 20 GeV to > 20 TeV and thus reveal the nature of the acceleration processes at work in these objects. We will show the first results of our lightcurve simulations and long-term behavior of AGN as will be observed by CTA, based on state-of-art particle acceleration models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.14208v1-abstract-full').style.display = 'none'; document.getElementById('2304.14208v1-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Proceedings for Gamma 2022, 8 pages, 6 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/2304.08816">arXiv:2304.08816</a> <span> [<a href="https://arxiv.org/pdf/2304.08816">pdf</a>, <a href="https://arxiv.org/format/2304.08816">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/10.1051/0004-6361/202346284">10.1051/0004-6361/202346284 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-ray flashes from the low-mass X-ray binary IGR J17407-2808 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ducci%2C+L">L. Ducci</a>, <a href="/search/astro-ph?searchtype=author&query=Malacaria%2C+C">C. Malacaria</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">E. Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Berton%2C+M">M. Berton</a>, <a href="/search/astro-ph?searchtype=author&query=Santangelo%2C+A">A. Santangelo</a>, <a href="/search/astro-ph?searchtype=author&query=Congiu%2C+E">E. Congiu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.08816v1-abstract-short" style="display: inline;"> IGR J17407-2808 is an enigmatic and poorly studied X-ray binary that was recently observed quasi-simultaneously with NuSTAR and XMM-Newton. In this paper we report the results of this observational campaign. During the first 60 ks of observation, the source was caught in a relatively low emission state, characterised by a modest variability and an average flux of ~8.3E-13 erg/cm^2/s (4-60 keV). Af… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08816v1-abstract-full').style.display = 'inline'; document.getElementById('2304.08816v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.08816v1-abstract-full" style="display: none;"> IGR J17407-2808 is an enigmatic and poorly studied X-ray binary that was recently observed quasi-simultaneously with NuSTAR and XMM-Newton. In this paper we report the results of this observational campaign. During the first 60 ks of observation, the source was caught in a relatively low emission state, characterised by a modest variability and an average flux of ~8.3E-13 erg/cm^2/s (4-60 keV). Afterwards, IGR J17407-2808 entered a significantly more active emission state that persisted for the remaining ~40 ks of the NuSTAR observation. During this state, IGR J17407-2808 displayed several fast X-ray flares, featuring durations of ~1-100 s and profiles with either single or multiple peaks. The source flux in the flaring state reached values as high as 2E-9 erg/cm^2/s (4-60 keV), leading to a measured dynamic range during the NuSTAR and XMM-Newton campaign of >~ 10^3. We also analysed available archival photometric near-infrared data of IGR J17407-2808 to improve the constraints available so far on the the nature of the donor star hosted in this system. Our analysis shows that the donor star can be either a rare K or M-type sub-subgiant or an K type main sequence star, or sub-giant star. Our findings support the classification of IGR J17407-2808 as a low-mass X-ray binary. We discuss the source X-ray behaviour as recorded by NuSTAR and XMM-Newton in view of this revised classification. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08816v1-abstract-full').style.display = 'none'; document.getElementById('2304.08816v1-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">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 674, A100 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.15007">arXiv:2303.15007</a> <span> [<a href="https://arxiv.org/pdf/2303.15007">pdf</a>, <a href="https://arxiv.org/format/2303.15007">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1016/j.astropartphys.2023.102850">10.1016/j.astropartphys.2023.102850 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sensitivity of the Cherenkov Telescope Array to spectral signatures of hadronic PeVatrons with application to Galactic Supernova Remnants </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Consortium%2C+T+C+T+A">The Cherenkov Telescope Array Consortium</a>, <a href="/search/astro-ph?searchtype=author&query=Acero%2C+F">F. Acero</a>, <a href="/search/astro-ph?searchtype=author&query=Acharyya%2C+A">A. Acharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Adam%2C+R">R. Adam</a>, <a href="/search/astro-ph?searchtype=author&query=Aguasca-Cabot%2C+A">A. Aguasca-Cabot</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Aguirre-Santaella%2C+A">A. Aguirre-Santaella</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+J">J. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Aloisio%2C+R">R. Aloisio</a>, <a href="/search/astro-ph?searchtype=author&query=Crespo%2C+N+%C3%81">N. 脕lvarez Crespo</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amati%2C+L">L. Amati</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Ambrosi%2C+G">G. Ambrosi</a>, <a href="/search/astro-ph?searchtype=author&query=Ang%C3%BCner%2C+E+O">E. O. Ang眉ner</a>, <a href="/search/astro-ph?searchtype=author&query=Aramo%2C+C">C. Aramo</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Armstrong%2C+T">T. Armstrong</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+K">K. Asano</a>, <a href="/search/astro-ph?searchtype=author&query=Ascasibar%2C+Y">Y. Ascasibar</a>, <a href="/search/astro-ph?searchtype=author&query=Aschersleben%2C+J">J. Aschersleben</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Baktash%2C+A">A. Baktash</a>, <a href="/search/astro-ph?searchtype=author&query=Balazs%2C+C">C. Balazs</a>, <a href="/search/astro-ph?searchtype=author&query=Balbo%2C+M">M. Balbo</a> , et al. (334 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.15007v1-abstract-short" style="display: inline;"> The local Cosmic Ray (CR) energy spectrum exhibits a spectral softening at energies around 3~PeV. Sources which are capable of accelerating hadrons to such energies are called hadronic PeVatrons. However, hadronic PeVatrons have not yet been firmly identified within the Galaxy. Several source classes, including Galactic Supernova Remnants (SNRs), have been proposed as PeVatron candidates. The pote… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.15007v1-abstract-full').style.display = 'inline'; document.getElementById('2303.15007v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.15007v1-abstract-full" style="display: none;"> The local Cosmic Ray (CR) energy spectrum exhibits a spectral softening at energies around 3~PeV. Sources which are capable of accelerating hadrons to such energies are called hadronic PeVatrons. However, hadronic PeVatrons have not yet been firmly identified within the Galaxy. Several source classes, including Galactic Supernova Remnants (SNRs), have been proposed as PeVatron candidates. The potential to search for hadronic PeVatrons with the Cherenkov Telescope Array (CTA) is assessed. The focus is on the usage of very high energy $纬$-ray spectral signatures for the identification of PeVatrons. Assuming that SNRs can accelerate CRs up to knee energies, the number of Galactic SNRs which can be identified as PeVatrons with CTA is estimated within a model for the evolution of SNRs. Additionally, the potential of a follow-up observation strategy under moonlight conditions for PeVatron searches is investigated. Statistical methods for the identification of PeVatrons are introduced, and realistic Monte--Carlo simulations of the response of the CTA observatory to the emission spectra from hadronic PeVatrons are performed. Based on simulations of a simplified model for the evolution for SNRs, the detection of a $纬$-ray signal from in average 9 Galactic PeVatron SNRs is expected to result from the scan of the Galactic plane with CTA after 10 hours of exposure. CTA is also shown to have excellent potential to confirm these sources as PeVatrons in deep observations with $\mathcal{O}(100)$ hours of exposure per source. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.15007v1-abstract-full').style.display = 'none'; document.getElementById('2303.15007v1-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 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">34 pages, 16 figures, Accepted for publication in Astroparticle Physics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.05534">arXiv:2303.05534</a> <span> [<a href="https://arxiv.org/pdf/2303.05534">pdf</a>, <a href="https://arxiv.org/ps/2303.05534">ps</a>, <a href="https://arxiv.org/format/2303.05534">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/10.1051/0004-6361/202345936">10.1051/0004-6361/202345936 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Long-term Swift and Mets盲hovi monitoring of SDSS J164100.10+345452.7 reveals multi-wavelength correlated variability </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=L%C3%A4hteenm%C3%A4ki%2C+A">A. L盲hteenm盲ki</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Foschini%2C+L">L. Foschini</a>, <a href="/search/astro-ph?searchtype=author&query=Berton%2C+M">M. Berton</a>, <a href="/search/astro-ph?searchtype=author&query=Raiteri%2C+C+M">C. M. Raiteri</a>, <a href="/search/astro-ph?searchtype=author&query=Braito%2C+V">V. Braito</a>, <a href="/search/astro-ph?searchtype=author&query=Ciroi%2C+S">S. Ciroi</a>, <a href="/search/astro-ph?searchtype=author&query=J%C3%A4rvel%C3%A4%2C+E">E. J盲rvel盲</a>, <a href="/search/astro-ph?searchtype=author&query=Baitieri%2C+S">S. Baitieri</a>, <a href="/search/astro-ph?searchtype=author&query=Varglund%2C+I">I. Varglund</a>, <a href="/search/astro-ph?searchtype=author&query=Tornikoski%2C+M">M. Tornikoski</a>, <a href="/search/astro-ph?searchtype=author&query=Suutarinen%2C+S">S. Suutarinen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.05534v1-abstract-short" style="display: inline;"> We report on the first multi-wavelength Swift monitoring campaign performed on SDSS J164100.10+345452.7, a nearby narrow-line Seyfert 1 galaxy formerly known as radio quiet which was recently detected both in the radio (at 37 GHz) and in the $纬$-rays, which hints at the presence of a relativistic jet. During our 20-month Swift campaign, while pursuing the primary goal of assessing the baseline opt… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.05534v1-abstract-full').style.display = 'inline'; document.getElementById('2303.05534v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.05534v1-abstract-full" style="display: none;"> We report on the first multi-wavelength Swift monitoring campaign performed on SDSS J164100.10+345452.7, a nearby narrow-line Seyfert 1 galaxy formerly known as radio quiet which was recently detected both in the radio (at 37 GHz) and in the $纬$-rays, which hints at the presence of a relativistic jet. During our 20-month Swift campaign, while pursuing the primary goal of assessing the baseline optical/UV and X-ray properties of J1641, we caught two radio flaring episodes, one each year. Our strictly simultaneous multi-wavelength data closely match the radio flare and allow us to unambiguously link the jetted radio emission of J1641. Indeed, for the X-ray spectra preceding and following the radio flare a simple absorbed power-law model is not an adequate description, and an extra absorption component is required. The average spectrum of J1641 can be best described by an absorbed power law model with a photon index $螕=1.93\pm0.12$, modified by a partially covering neutral absorber with a covering fraction $f=0.91_{-0.03}^{+0.02}$. On the contrary, the X-ray spectrum closest to the radio flare does not require such extra absorber and is much harder ($螕_{\rm flare} \sim 0.7\pm0.4$), thus implying the emergence of a further, harder spectral component. We interpret this as the jet emission emerging from a gap in the absorber. The fractional variability we derive in the optical/UV and X-ray bands are found to be lower than the typical values reported in the literature, since our observations of J1641 are dominated by the source being in a low state. Under the assumption that the origin of the 37 GHz radio flare is the emergence of a jet from an obscuring screen also observed in the X-rays, the derived total jet power is $P^{\rm tot}_{\rm jet}=3.5\times10^{42}$ erg s$^{-1}$, comparable to the lowest measured in the literature. [Abridged] <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.05534v1-abstract-full').style.display = 'none'; document.getElementById('2303.05534v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy and Astrophysics (13 pages, 4 figures, 8 tables)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 673, A85 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.10939">arXiv:2302.10939</a> <span> [<a href="https://arxiv.org/pdf/2302.10939">pdf</a>, <a href="https://arxiv.org/format/2302.10939">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/acb2cb">10.3847/1538-4357/acb2cb <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Clumpy wind studies and the non-detection of cyclotron line in OAO 1657-415 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Pradhan%2C+P">Pragati Pradhan</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">Carlo Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Paul%2C+B">Biswajit Paul</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">Enrico Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Mellah%2C+I+E">Ileyk El Mellah</a>, <a href="/search/astro-ph?searchtype=author&query=Huenemoerder%2C+D+P">David P. Huenemoerder</a>, <a href="/search/astro-ph?searchtype=author&query=Steiner%2C+J+F">James F. Steiner</a>, <a href="/search/astro-ph?searchtype=author&query=Grinberg%2C+V">Victoria Grinberg</a>, <a href="/search/astro-ph?searchtype=author&query=Furst%2C+F">Felix Furst</a>, <a href="/search/astro-ph?searchtype=author&query=Maitra%2C+C">Chandreyee Maitra</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Patrizia Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Kretschma%2C+P">Peter Kretschma</a>, <a href="/search/astro-ph?searchtype=author&query=Kennea%2C+J">Jamie Kennea</a>, <a href="/search/astro-ph?searchtype=author&query=Chakrabarty%2C+D">Deepto Chakrabarty</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.10939v1-abstract-short" style="display: inline;"> Winds of massive stars are suspected to be inhomogeneous (or clumpy), which biases the measures of their mass loss rates. In High Mass X-ray Binaries (HMXBs), the compact object can be used as an orbiting X-ray point source to probe the wind and constrain its clumpiness. We perform spectro-timing analysis of the HMXB OAO 1657-415 with non-simultaneous NuSTAR and NICER observations. We compute the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.10939v1-abstract-full').style.display = 'inline'; document.getElementById('2302.10939v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.10939v1-abstract-full" style="display: none;"> Winds of massive stars are suspected to be inhomogeneous (or clumpy), which biases the measures of their mass loss rates. In High Mass X-ray Binaries (HMXBs), the compact object can be used as an orbiting X-ray point source to probe the wind and constrain its clumpiness. We perform spectro-timing analysis of the HMXB OAO 1657-415 with non-simultaneous NuSTAR and NICER observations. We compute the hardness ratio from the energy-resolved light curves, and using an adaptive rebinning technique, we thus select appropriate time segments to search for rapid spectral variations on timescales of a few hundreds to thousands of seconds. Column density and intensity of Iron K$伪$ line were strongly correlated, and the recorded spectral variations were consistent with accretion from a clumpy wind. We also illustrate a novel framework to measure clump sizes, masses in HMXBs more accurately based on absorption measurements and orbital parameters of the source. We then discuss the limitations posed by current X-ray spacecrafts in such measurements and present prospects with future X-ray missions. We find that the source pulse profiles show a moderate dependence on energy. We identify a previously undetected dip in the pulse profile visible throughout the NuSTAR observation near spin phase 0.15 possibly caused by intrinsic changes in accretion geometry close to the neutron star. We do not find any evidence for the debated cyclotron line at $\sim$ 36\,keV in the time-averaged or the phase-resolved spectra with NuSTAR. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.10939v1-abstract-full').style.display = 'none'; document.getElementById('2302.10939v1-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 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">32 pages, 11 figures in main text, 7 figures in Appendix, Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.03400">arXiv:2211.03400</a> <span> [<a href="https://arxiv.org/pdf/2211.03400">pdf</a>, <a href="https://arxiv.org/ps/2211.03400">ps</a>, <a href="https://arxiv.org/format/2211.03400">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/10.3390/universe8110587">10.3390/universe8110587 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Foschini%2C+L">Luigi Foschini</a>, <a href="/search/astro-ph?searchtype=author&query=Lister%2C+M+L">Matthew L. Lister</a>, <a href="/search/astro-ph?searchtype=author&query=Andernach%2C+H">Heinz Andernach</a>, <a href="/search/astro-ph?searchtype=author&query=Ciroi%2C+S">Stefano Ciroi</a>, <a href="/search/astro-ph?searchtype=author&query=Marziani%2C+P">Paola Marziani</a>, <a href="/search/astro-ph?searchtype=author&query=Ant%C3%B3n%2C+S">Sonia Ant贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Berton%2C+M">Marco Berton</a>, <a href="/search/astro-ph?searchtype=author&query=Bont%C3%A0%2C+E+D">Elena Dalla Bont脿</a>, <a href="/search/astro-ph?searchtype=author&query=J%C3%A4rvel%C3%A4%2C+E">Emilia J盲rvel盲</a>, <a href="/search/astro-ph?searchtype=author&query=March%C3%A3%2C+M+J+M">Maria J. M. March茫</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Patrizia Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Tornikoski%2C+M">Merja Tornikoski</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">Stefano Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Vietri%2C+A">Amelia Vietri</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.03400v1-abstract-short" style="display: inline;"> We considered the fourth catalog of gamma-ray point sources produced by the Fermi Large Area Telescope (LAT) and selected only jetted active galactic nuclei (AGN) or sources with no specific classification, but with a low-frequency counterpart. Our final list is composed of 2980 gamma-ray point sources. We then searched for optical spectra in all the available literature and publicly available dat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.03400v1-abstract-full').style.display = 'inline'; document.getElementById('2211.03400v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.03400v1-abstract-full" style="display: none;"> We considered the fourth catalog of gamma-ray point sources produced by the Fermi Large Area Telescope (LAT) and selected only jetted active galactic nuclei (AGN) or sources with no specific classification, but with a low-frequency counterpart. Our final list is composed of 2980 gamma-ray point sources. We then searched for optical spectra in all the available literature and publicly available databases, to measure redshifts and to confirm or change the original LAT classification. Our final list of gamma-ray emitting jetted AGN is composed of BL Lac Objects (40%), flat-spectrum radio quasars (23%), misaligned AGN (2.8%), narrow-line Seyfert 1, Seyfert, and low-ionization nuclear emission-line region galaxies (1.9%). We also found a significant number of objects changing from one type to another, and vice versa (changing-look AGN, 1.1%). About 30% of gamma-ray sources still have an ambiguous classification or lack one altogether. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.03400v1-abstract-full').style.display = 'none'; document.getElementById('2211.03400v1-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 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 5 figures, 1 Table. Accepted for publication on Universe, Special Issue "Black Holes and Relativistic Jets", edited by I. Dutan and N. R. MacDonald. This preprint contains only the main text. The full tables A1 and A2 are available on the journal web site (https://www.mdpi.com/2218-1997/8/11/587)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Universe 2022, 8(11), 587 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.03181">arXiv:2208.03181</a> <span> [<a href="https://arxiv.org/pdf/2208.03181">pdf</a>, <a href="https://arxiv.org/format/2208.03181">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1016/j.jheap.2022.06.006">10.1016/j.jheap.2022.06.006 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Galactic Observatory Science with the ASTRI Mini-Array at the Observatorio del Teide </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=D%27A%C3%AC%2C+A">A. D'A矛</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">A. Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Compagnino%2C+A+A">A. A. Compagnino</a>, <a href="/search/astro-ph?searchtype=author&query=Fiori%2C+M">M. Fiori</a>, <a href="/search/astro-ph?searchtype=author&query=Giuliani%2C+A">A. Giuliani</a>, <a href="/search/astro-ph?searchtype=author&query=La+Palombara%2C+N">N. La Palombara</a>, <a href="/search/astro-ph?searchtype=author&query=Paizis%2C+A">A. Paizis</a>, <a href="/search/astro-ph?searchtype=author&query=Piano%2C+G">G. Piano</a>, <a href="/search/astro-ph?searchtype=author&query=Saturni%2C+F+G">F. G. Saturni</a>, <a href="/search/astro-ph?searchtype=author&query=Tutone%2C+A">A. Tutone</a>, <a href="/search/astro-ph?searchtype=author&query=Belfiore%2C+A">A. Belfiore</a>, <a href="/search/astro-ph?searchtype=author&query=Cardillo%2C+M">M. Cardillo</a>, <a href="/search/astro-ph?searchtype=author&query=Crestan%2C+S">S. Crestan</a>, <a href="/search/astro-ph?searchtype=author&query=Cusumano%2C+G">G. Cusumano</a>, <a href="/search/astro-ph?searchtype=author&query=Della+Valle%2C+M">M. Della Valle</a>, <a href="/search/astro-ph?searchtype=author&query=Del+Santo%2C+M">M. Del Santo</a>, <a href="/search/astro-ph?searchtype=author&query=La+Barbera%2C+A">A. La Barbera</a>, <a href="/search/astro-ph?searchtype=author&query=La+Parola%2C+V">V. La Parola</a>, <a href="/search/astro-ph?searchtype=author&query=Lombardi%2C+S">S. Lombardi</a>, <a href="/search/astro-ph?searchtype=author&query=Mereghetti%2C+S">S. Mereghetti</a>, <a href="/search/astro-ph?searchtype=author&query=Morlino%2C+G">G. Morlino</a>, <a href="/search/astro-ph?searchtype=author&query=Pintore%2C+F">F. Pintore</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a> , et al. (30 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.03181v1-abstract-short" style="display: inline;"> The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Mini-Array will be composed of nine imaging atmospheric Cherenkov telescopes at the Observatorio del Teide site. The array will be best suited for astrophysical observations in the 0.3-200 TeV range with an angular resolution of few arc-minutes and an energy resolution of 10-15\%. A core-science programme in the first four years… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.03181v1-abstract-full').style.display = 'inline'; document.getElementById('2208.03181v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.03181v1-abstract-full" style="display: none;"> The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Mini-Array will be composed of nine imaging atmospheric Cherenkov telescopes at the Observatorio del Teide site. The array will be best suited for astrophysical observations in the 0.3-200 TeV range with an angular resolution of few arc-minutes and an energy resolution of 10-15\%. A core-science programme in the first four years will be devoted to a limited number of key targets, addressing the most important open scientific questions in the very-high energy domain. At the same time, thanks to a wide field of view of about 10 degrees, ASTRI Mini-Array will observe many additional field sources, which will constitute the basis for the long-term observatory programme that will eventually cover all the accessible sky. In this paper, we review different astrophysical Galactic environments, e.g. pulsar wind nebulae, supernova remnants, and gamma-ray binaries, and show the results from a set of ASTRI Mini-Array simulations of some of these field sources made to highlight the expected performance of the array (even at large offset angles) and the important additional observatory science that will complement the core-science program. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.03181v1-abstract-full').style.display = 'none'; document.getElementById('2208.03181v1-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Journal of High-Energy Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> JHEAP, Volume 35, August 2022, Pages 139-175 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.03177">arXiv:2208.03177</a> <span> [<a href="https://arxiv.org/pdf/2208.03177">pdf</a>, <a href="https://arxiv.org/format/2208.03177">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1016/j.jheap.2022.05.005">10.1016/j.jheap.2022.05.005 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> ASTRI Mini-Array Core Science at the Observatorio del Teide </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">A. Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Cardillo%2C+M">M. Cardillo</a>, <a href="/search/astro-ph?searchtype=author&query=Catalano%2C+O">O. Catalano</a>, <a href="/search/astro-ph?searchtype=author&query=Franceschini%2C+A">A. Franceschini</a>, <a href="/search/astro-ph?searchtype=author&query=Lombardi%2C+S">S. Lombardi</a>, <a href="/search/astro-ph?searchtype=author&query=Nava%2C+L">L. Nava</a>, <a href="/search/astro-ph?searchtype=author&query=Pintore%2C+F">F. Pintore</a>, <a href="/search/astro-ph?searchtype=author&query=Stamerra%2C+A">A. Stamerra</a>, <a href="/search/astro-ph?searchtype=author&query=Tavecchio%2C+F">F. Tavecchio</a>, <a href="/search/astro-ph?searchtype=author&query=Zampieri%2C+L">L. Zampieri</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</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=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzalez%2C+J+B">J. Becerra Gonzalez</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnoli%2C+G">G. Bonnoli</a>, <a href="/search/astro-ph?searchtype=author&query=Bottcher%2C+M">M. Bottcher</a>, <a href="/search/astro-ph?searchtype=author&query=Brunetti%2C+G">G. Brunetti</a>, <a href="/search/astro-ph?searchtype=author&query=Compagnino%2C+A+A">A. A. Compagnino</a>, <a href="/search/astro-ph?searchtype=author&query=Crestan%2C+S">S. Crestan</a>, <a href="/search/astro-ph?searchtype=author&query=Ai%2C+A+D">A. D Ai</a>, <a href="/search/astro-ph?searchtype=author&query=Fiori%2C+M">M. Fiori</a>, <a href="/search/astro-ph?searchtype=author&query=Galanti%2C+G">G. Galanti</a> , et al. (62 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.03177v1-abstract-short" style="display: inline;"> The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.03177v1-abstract-full').style.display = 'inline'; document.getElementById('2208.03177v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.03177v1-abstract-full" style="display: none;"> The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily. The ASTRI Mini-Array will surpass the current Cherenkov telescope array differential sensitivity above a few tera-electronvolt (TeV), extending the energy band well above hundreds of TeV. This will allow us to explore a new window of the electromagnetic spectrum, by convolving the sensitivity performance with excellent angular and energy resolution figures. In this paper we describe the Core Science that we will address during the first four years of operation, providing examples of the breakthrough results that we will obtain when dealing with current open questions, such as the acceleration of cosmic rays, cosmology and fundamental physics and the new window, for the TeV energy band, of the time-domain astrophysics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.03177v1-abstract-full').style.display = 'none'; document.getElementById('2208.03177v1-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in Journal of High Energy Astrophysics. 46 Figures, 7 Tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of High Energy Astrophysics, Volume 35, August 2022, Pages 1-42 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.03176">arXiv:2208.03176</a> <span> [<a href="https://arxiv.org/pdf/2208.03176">pdf</a>, <a href="https://arxiv.org/format/2208.03176">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1016/j.jheap.2022.06.004">10.1016/j.jheap.2022.06.004 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Extragalactic Observatory Science with the ASTRI Mini-Array at the Observatorio del Teide </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Saturni%2C+F+G">F. G. Saturni</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C+H+E">C. H. E. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Balmaverde%2C+B">B. Balmaverde</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=Caccianiga%2C+A">A. Caccianiga</a>, <a href="/search/astro-ph?searchtype=author&query=Capalbi%2C+M">M. Capalbi</a>, <a href="/search/astro-ph?searchtype=author&query=Lamastra%2C+A">A. Lamastra</a>, <a href="/search/astro-ph?searchtype=author&query=Lombardi%2C+S">S. Lombardi</a>, <a href="/search/astro-ph?searchtype=author&query=Lucarelli%2C+F">F. Lucarelli</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</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=Pino%2C+E+M+d+G+D">E. M. de Gouveia Dal Pino</a>, <a href="/search/astro-ph?searchtype=author&query=Della+Ceca%2C+R">R. Della Ceca</a>, <a href="/search/astro-ph?searchtype=author&query=Green%2C+J+G">J. G. Green</a>, <a href="/search/astro-ph?searchtype=author&query=Pagliaro%2C+A">A. Pagliaro</a>, <a href="/search/astro-ph?searchtype=author&query=Righi%2C+C">C. Righi</a>, <a href="/search/astro-ph?searchtype=author&query=Tavecchio%2C+F">F. Tavecchio</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Wolter%2C+A">A. Wolter</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%B6ttcher%2C+M">M. B枚ttcher</a>, <a href="/search/astro-ph?searchtype=author&query=Brunetti%2C+G">G. Brunetti</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+P">P. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulgarelli%2C+A">A. Bulgarelli</a> , et al. (25 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.03176v1-abstract-short" style="display: inline;"> The ASTRI Mini-Array is a next-generation system of nine imaging atmospheric Cherenkov telescopes that is going to be built at the Observatorio del Teide site. After a first phase, in which the instrument will be operated as an experiment prioritizing a schedule of primary science cases, an observatory phase is foreseen in which other significant targets will be pointed. We focus on the observatio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.03176v1-abstract-full').style.display = 'inline'; document.getElementById('2208.03176v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.03176v1-abstract-full" style="display: none;"> The ASTRI Mini-Array is a next-generation system of nine imaging atmospheric Cherenkov telescopes that is going to be built at the Observatorio del Teide site. After a first phase, in which the instrument will be operated as an experiment prioritizing a schedule of primary science cases, an observatory phase is foreseen in which other significant targets will be pointed. We focus on the observational feasibility of extragalactic sources and on astrophysical processes that best complement and expand the ASTRI Mini-Array core science, presenting the most relevant examples that are at reach of detection over long-term time scales and whose observation can provide breakthrough achievements in the very-high energy extragalactic science. Such examples cover a wide range of $纬$-ray emitters, including the study of AGN low states in the multi-TeV energy range, the possible detection of Seyfert galaxies with long exposures and the searches of dark matter lines above 10 TeV. Simulations of the presented objects show that the instrument performance will be competitive at multi-TeV energies with respect to current arrays of Cherenkov telescopes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.03176v1-abstract-full').style.display = 'none'; document.getElementById('2208.03176v1-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 10 figures, 7 tables, published on JHEAp</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of High Energy Astrophysics 35 (2022), 91-111 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2205.03023">arXiv:2205.03023</a> <span> [<a href="https://arxiv.org/pdf/2205.03023">pdf</a>, <a href="https://arxiv.org/format/2205.03023">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/10.1051/0004-6361/202243294">10.1051/0004-6361/202243294 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> XMM-Newton and Swift observations of supergiant high mass X-ray binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">Carlo Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">Enrico Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Patrizia Romano</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2205.03023v1-abstract-short" style="display: inline;"> Wind-fed supergiant X-ray binaries are precious laboratories not only to study accretion under extreme gravity and magnetic field conditions, but also to probe still highly debated properties of massive star winds. These includes the so-called clumps, originated from the inherent instability of line driven winds, and larger structures. In this paper, we report on the results of the last (and not y… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.03023v1-abstract-full').style.display = 'inline'; document.getElementById('2205.03023v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.03023v1-abstract-full" style="display: none;"> Wind-fed supergiant X-ray binaries are precious laboratories not only to study accretion under extreme gravity and magnetic field conditions, but also to probe still highly debated properties of massive star winds. These includes the so-called clumps, originated from the inherent instability of line driven winds, and larger structures. In this paper, we report on the results of the last (and not yet published) monitoring campaigns that our group has been carrying out since 2007 with both XMM-Newton and the Swift Neil Gehrels observatory. Data collected with the EPIC cameras on-board XMM-Newton allow us to carry out a detailed hardness ratio-resolved spectral analysis that can be used as an efficient way to detect spectral variations associated to the presence of clumps. Long-term observations with the XRT on-board Swift, evenly sampling the X-ray emission of supergiant X-ray binaries over many different orbital cycles, are exploited to look for the presence of large scale structures in the medium surrounding the compact objects. The results reported in this paper represent the outcomes of the concluded observational campaigns we carried out on the supergiant X-ray binaries 4U 1907+09, IGR J16393-4643, IGR J19140+0951, and XTE J1855-026, as well as the supergiant fast X-ray transients IGR J17503-2636, IGR J18410-0535, and IGR J11215-5952. All results are discussed in the context of wind-fed supergiant X-ray binaries and shall ideally serve to optimally shape the next observational campaigns aimed at sources in the same classes. We show in one of the paper appendices that IGR J17315-3221, preliminary classified in the literature as a possible supergiant X-ray binary discovered by INTEGRAL, is the product of a data analysis artifact and should thus be disregarded for future studies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.03023v1-abstract-full').style.display = 'none'; document.getElementById('2205.03023v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 664, A99 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.16347">arXiv:2203.16347</a> <span> [<a href="https://arxiv.org/pdf/2203.16347">pdf</a>, <a href="https://arxiv.org/ps/2203.16347">ps</a>, <a href="https://arxiv.org/format/2203.16347">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/stac907">10.1093/mnras/stac907 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Symbiotic X-ray binaries Sct X-1, 4U 1700+24 and IGR J17329-2731 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">E. Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">C. Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Oskinova%2C+L">L. Oskinova</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.16347v1-abstract-short" style="display: inline;"> Symbiotic X-ray binaries are systems hosting a neutron star accreting form the wind of a late type companion. These are rare objects and so far only a handful of them are known. One of the most puzzling aspects of the symbiotic X-ray binaries is the possibility that they contain strongly magnetized neutron stars. These are expected to be evolutionary much younger compared to their evolved companio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.16347v1-abstract-full').style.display = 'inline'; document.getElementById('2203.16347v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.16347v1-abstract-full" style="display: none;"> Symbiotic X-ray binaries are systems hosting a neutron star accreting form the wind of a late type companion. These are rare objects and so far only a handful of them are known. One of the most puzzling aspects of the symbiotic X-ray binaries is the possibility that they contain strongly magnetized neutron stars. These are expected to be evolutionary much younger compared to their evolved companions and could thus be formed through the (yet poorly known) accretion induced collapse of a white dwarf. In this paper, we perform a broad-band X-ray and soft $纬$-ray spectroscopy of two known symbiotic binaries, Sct X-1 and 4U 1700+24, looking for the presence of cyclotron scattering features that could confirm the presence of strongly magnetized NSs. We exploited available Chandra, Swift, and NuSTAR data. We find no evidence of cyclotron resonant scattering features (CRSFs) in the case of Sct X-1 but in the case of 4U 1700+24 we suggest the presence of a possible CRSF at $\sim$16 keV and its first harmonic at $\sim$31 keV, although we could not exclude alternative spectral models for the broad-band fit. If confirmed by future observations, 4U 1700+24 could be the second symbiotic X-ray binary with a highly magnetized accretor. We also report about our long-term monitoring of the last discovered symbiotic X-ray binary IGR J17329-2731 performed with Swift/XRT. The monitoring revealed that, as predicted, in 2017 this object became a persistent and variable source, showing X-ray flares lasting for a few days and intriguing obscuration events that are interpreted in the context of clumpy wind accretion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.16347v1-abstract-full').style.display = 'none'; document.getElementById('2203.16347v1-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 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication 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/2202.09946">arXiv:2202.09946</a> <span> [<a href="https://arxiv.org/pdf/2202.09946">pdf</a>, <a href="https://arxiv.org/ps/2202.09946">ps</a>, <a href="https://arxiv.org/format/2202.09946">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142973">10.1051/0004-6361/202142973 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> IBIS-A: The IBIS data Archive. High resolution observations of the solar photosphere and chromosphere with contextual data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ermolli%2C+I">Ilaria Ermolli</a>, <a href="/search/astro-ph?searchtype=author&query=Giorgi%2C+F">Fabrizio Giorgi</a>, <a href="/search/astro-ph?searchtype=author&query=Murabito%2C+M">Mariarita Murabito</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">Marco Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Guido%2C+V">Vincenzo Guido</a>, <a href="/search/astro-ph?searchtype=author&query=Molinaro%2C+M">Marco Molinaro</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">Salvatore L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Viavattene%2C+G">Giorgio Viavattene</a>, <a href="/search/astro-ph?searchtype=author&query=Cauzzi%2C+G">Gianna Cauzzi</a>, <a href="/search/astro-ph?searchtype=author&query=Criscuoli%2C+S">Serena Criscuoli</a>, <a href="/search/astro-ph?searchtype=author&query=Reardon%2C+K+P">Kevin P. Reardon</a>, <a href="/search/astro-ph?searchtype=author&query=Tritschler%2C+A">Alexandra Tritschler</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="2202.09946v1-abstract-short" style="display: inline;"> The IBIS data Archive (IBIS-A) stores data acquired with the Interferometric BIdimensional Spectropolarimeter (IBIS), which was operated at the Dunn Solar Telescope of the US National Solar Observatory from 2003 to 2019. The instrument provided series of high-resolution narrowband spectropolarimetric imaging observations of the photosphere and chromosphere in the range 5800$-$8600 脜~ and co-tempor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.09946v1-abstract-full').style.display = 'inline'; document.getElementById('2202.09946v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.09946v1-abstract-full" style="display: none;"> The IBIS data Archive (IBIS-A) stores data acquired with the Interferometric BIdimensional Spectropolarimeter (IBIS), which was operated at the Dunn Solar Telescope of the US National Solar Observatory from 2003 to 2019. The instrument provided series of high-resolution narrowband spectropolarimetric imaging observations of the photosphere and chromosphere in the range 5800$-$8600 脜~ and co-temporal broadband observations in the same spectral range and with the same field of view of the polarimetric data. We present the data currently stored in IBIS-A, as well as the interface utilized to explore such data and facilitate its scientific exploitation. To this purpose we also describe the use of IBIS-A data in recent and undergoing studies relevant to solar physics and space weather research. IBIS-A includes raw and calibrated observations, as well as science-ready data. The latter comprise maps of the circular, linear, and net circular polarization, and of the magnetic and velocity fields derived for a significant fraction of the series available in the archive. IBIS-A furthermore contains links to observations complementary to the IBIS data, such as co-temporal high-resolution observations of the solar atmosphere available from the instruments onboard the Hinode and IRIS satellites, and full-disc multiband images from INAF solar telescopes. IBIS-A currently consists of 30 TB of data taken with IBIS during 28 observing campaigns performed in 2008 and from 2012 to 2019 on 159 days. Metadata and movies of each calibrated and science-ready series are also available to help users evaluating observing conditions. IBIS-A represents a unique resource for investigating the plasma processes in the solar atmosphere and the solar origin of space weather events. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.09946v1-abstract-full').style.display = 'none'; document.getElementById('2202.09946v1-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 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">22 pages, 13 figures, accepted for publication in Astronomy and Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 661, A74 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.08972">arXiv:2111.08972</a> <span> [<a href="https://arxiv.org/pdf/2111.08972">pdf</a>, <a href="https://arxiv.org/ps/2111.08972">ps</a>, <a href="https://arxiv.org/format/2111.08972">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s11207-021-01932-z">10.1007/s11207-021-01932-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the evolution of a sub-C class flare: a showcase for the capabilities of the revamped Catania Solar Telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">Salvo L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Costa%2C+P">Pierfrancesco Costa</a>, <a href="/search/astro-ph?searchtype=author&query=Falco%2C+M">Mariachiara Falco</a>, <a href="/search/astro-ph?searchtype=author&query=Buttaccio%2C+S">Salvatore Buttaccio</a>, <a href="/search/astro-ph?searchtype=author&query=Costa%2C+A">Alessandro Costa</a>, <a href="/search/astro-ph?searchtype=author&query=Martinetti%2C+E">Eugenio Martinetti</a>, <a href="/search/astro-ph?searchtype=author&query=Occhipinti%2C+G">Giovanni Occhipinti</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Ventura%2C+R">Rita Ventura</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">Giuseppe E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Zuccarello%2C+F">Francesca Zuccarello</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2111.08972v2-abstract-short" style="display: inline;"> Solar flares are occasionally responsible for severe Space Weather events, which can affect space-borne and ground-based infrastructures, endangering anthropic technological activities and even human health and safety. Thus, an essential activity in the framework of Space Weather monitoring is devoted to the observation of the activity level of the Sun. In this context, the acquisition system of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.08972v2-abstract-full').style.display = 'inline'; document.getElementById('2111.08972v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.08972v2-abstract-full" style="display: none;"> Solar flares are occasionally responsible for severe Space Weather events, which can affect space-borne and ground-based infrastructures, endangering anthropic technological activities and even human health and safety. Thus, an essential activity in the framework of Space Weather monitoring is devoted to the observation of the activity level of the Sun. In this context, the acquisition system of the Catania Solar Telescope has been recently upgraded in order to improve its contribution to the European Space Agency (ESA) - Space Weather Service Network through the ESA Portal, which represents the main asset for Space Weather in Europe. Here, we describe the hardware and software upgrades of the Catania Solar Telescope and the main data products provided by this facility, which include full-disc images of the photosphere and chromosphere, together with a detailed characterization of the sunspot groups. As a showcase of the observational capabilities of the revamped Catania Solar Telescope, we report the analysis of a B5.4 class flare occurred on 2020 December 7, simultaneously observed by the IRIS and SDO satellites. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.08972v2-abstract-full').style.display = 'none'; document.getElementById('2111.08972v2-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 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.11031">arXiv:2110.11031</a> <span> [<a href="https://arxiv.org/pdf/2110.11031">pdf</a>, <a href="https://arxiv.org/format/2110.11031">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="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</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/ac282f">10.3847/2041-8213/ac282f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Exploring the Solar Wind from its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter - Parker Solar Probe Quadrature </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">Ester Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">Alessandro Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">Giuseppe E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S">Silvio Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=Habbal%2C+S">Shadia Habbal</a>, <a href="/search/astro-ph?searchtype=author&query=Perrone%2C+D">Denise Perrone</a>, <a href="/search/astro-ph?searchtype=author&query=Pinto%2C+R+F">Rui F. Pinto</a>, <a href="/search/astro-ph?searchtype=author&query=Sorriso-Valvo%2C+L">Luca Sorriso-Valvo</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Woodham%2C+L+D">Lloyd D. Woodham</a>, <a href="/search/astro-ph?searchtype=author&query=Zank%2C+G+P">Gary P. Zank</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Bale%2C+S+D">Stuart D. Bale</a>, <a href="/search/astro-ph?searchtype=author&query=Kasper%2C+J+C">Justin C. Kasper</a>, <a href="/search/astro-ph?searchtype=author&query=Auch%C3%A8re%2C+F">Fr茅d茅ric Auch猫re</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+R">Roberto Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">Gerardo Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Case%2C+A+W">Anthony W. Case</a>, <a href="/search/astro-ph?searchtype=author&query=Casini%2C+C">Chiara Casini</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">Marta Casti</a>, <a href="/search/astro-ph?searchtype=author&query=Chioetto%2C+P">Paolo Chioetto</a> , et al. (46 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="2110.11031v1-abstract-short" style="display: inline;"> This Letter addresses the first Solar Orbiter (SO) -- Parker Solar Probe (PSP) quadrature, occurring on January 18, 2021, to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO ca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.11031v1-abstract-full').style.display = 'inline'; document.getElementById('2110.11031v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.11031v1-abstract-full" style="display: none;"> This Letter addresses the first Solar Orbiter (SO) -- Parker Solar Probe (PSP) quadrature, occurring on January 18, 2021, to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO can be tracked to PSP, orbiting at 0.1 au, thus allowing the local properties of the solar wind to be linked to the coronal source region from where it originated. Thanks to the close approach of PSP to the Sun and the simultaneous Metis observation of the solar corona, the flow-aligned magnetic field and the bulk kinetic energy flux density can be empirically inferred along the coronal current sheet with an unprecedented accuracy, allowing in particular estimation of the Alfv茅n radius at 8.7 solar radii during the time of this event. This is thus the very first study of the same solar wind plasma as it expands from the sub-Alfv茅nic solar corona to just above the Alfv茅n surface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.11031v1-abstract-full').style.display = 'none'; document.getElementById('2110.11031v1-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 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Telloni, D., Andretta, V., Antonucci, E., et al. 2021, ApJL, 920, L14 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.01995">arXiv:2110.01995</a> <span> [<a href="https://arxiv.org/pdf/2110.01995">pdf</a>, <a href="https://arxiv.org/ps/2110.01995">ps</a>, <a href="https://arxiv.org/format/2110.01995">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> <p class="title is-5 mathjax"> A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei -- Preliminary Results </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Foschini%2C+L">L. Foschini</a>, <a href="/search/astro-ph?searchtype=author&query=Lister%2C+M+L">M. L. Lister</a>, <a href="/search/astro-ph?searchtype=author&query=Ant%C3%B3n%2C+S">S. Ant贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Berton%2C+M">M. Berton</a>, <a href="/search/astro-ph?searchtype=author&query=Ciroi%2C+S">S. Ciroi</a>, <a href="/search/astro-ph?searchtype=author&query=March%C3%A3%2C+M+J+M">M. J. M. March茫</a>, <a href="/search/astro-ph?searchtype=author&query=Tornikoski%2C+M">M. Tornikoski</a>, <a href="/search/astro-ph?searchtype=author&query=J%C3%A4rvel%C3%A4%2C+E">E. J盲rvel盲</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Bont%C3%A0%2C+E+D">E. Dalla Bont脿</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="2110.01995v1-abstract-short" style="display: inline;"> We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT). Our aim is to prepare a list of jetted AGN with known redshifts and classifications to be used to calibrate jet power. We searched in the available literature for all the published optical spectra and multiwavelength studies useful… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.01995v1-abstract-full').style.display = 'inline'; document.getElementById('2110.01995v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.01995v1-abstract-full" style="display: none;"> We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT). Our aim is to prepare a list of jetted AGN with known redshifts and classifications to be used to calibrate jet power. We searched in the available literature for all the published optical spectra and multiwavelength studies useful to characterize the sources. We found new, missed, or even forgotten information leading to a substantial change in the redshift values and classification of many sources. We present here the preliminary results of this analysis and some statistics based on the gamma-ray sources with right ascension within the interval $0^{\rm h}-12^{\rm h}$ (J2000). Although flat-spectrum radio quasars and BL Lac objects are still the dominant populations, there is a significant increase in the number of other objects, such as misaligned AGN, narrow-line Seyfert 1 galaxies, and Seyfert galaxies. We also introduced two new classes of objects: changing-look AGN and ambiguous sources. About one third of the sources remain unclassified. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.01995v1-abstract-full').style.display = 'none'; document.getElementById('2110.01995v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">19 pages, 2 figures, 1 table. Accepted for publication on Universe (MDPI). The full list is available on the published article</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.01272">arXiv:2110.01272</a> <span> [<a href="https://arxiv.org/pdf/2110.01272">pdf</a>, <a href="https://arxiv.org/format/2110.01272">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/10.1088/1674-4527/21/12/313">10.1088/1674-4527/21/12/313 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Comparative case study of two methods to assess the eruptive potential of selected active regions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zuccarello%2C+F">Francesca Zuccarello</a>, <a href="/search/astro-ph?searchtype=author&query=Ermolli%2C+I">Ilaria Ermolli</a>, <a href="/search/astro-ph?searchtype=author&query=Korsos%2C+M+B">Marianna B. Korsos</a>, <a href="/search/astro-ph?searchtype=author&query=Giorgi%2C+F">Fabrizio Giorgi</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">Salvo L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Erdelyi%2C+R">Robertus Erdelyi</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</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="2110.01272v2-abstract-short" style="display: inline;"> Solar eruptive events, like flares and coronal mass ejections, are characterized by the rapid release of energy that can give rise to emission of radiation across the entire electromagnetic spectrum and to an abrupt significant increase in the kinetic energy of particles. These energetic phenomena can have important effects on the Space Weather conditions and therefore it is necessary to understan… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.01272v2-abstract-full').style.display = 'inline'; document.getElementById('2110.01272v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.01272v2-abstract-full" style="display: none;"> Solar eruptive events, like flares and coronal mass ejections, are characterized by the rapid release of energy that can give rise to emission of radiation across the entire electromagnetic spectrum and to an abrupt significant increase in the kinetic energy of particles. These energetic phenomena can have important effects on the Space Weather conditions and therefore it is necessary to understand their origin, in particular, what is the eruptive potential of an active region (AR). In these case studies, we compare two distinct methods that were used in previous works to investigate the variations of some characteristic physical parameters during the pre-flare states of flaring ARs. These methods consider: i) the magnetic flux evolution and the magnetic helicity accumulation, and ii) the fractal and multi-fractal properties of flux concentrations in ARs. Our comparative analysis is based on time series of photospheric data obtained by the Solar Dynamics Observatory between March 2011 and June 2013. We selected two distinct samples of ARs: one is distinguished by the occurrence of more energetic M- and X-class flare events, that may have a rapid effect on not just the near-Earth space, but also on the terrestrial environment; the second is characterized by no-flares or having just few C- and B-class flares. We found that the two tested methods complement each other in their ability to assess the eruptive potentials of ARs and could be employed to identify ARs prone to flaring activity. Based on the presented case study, we suggest that using a combination of different methods may aid to identify more reliably the eruptive potentials of ARs and help to better understand the pre-flare states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.01272v2-abstract-full').style.display = 'none'; document.getElementById('2110.01272v2-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.05957">arXiv:2108.05957</a> <span> [<a href="https://arxiv.org/pdf/2108.05957">pdf</a>, <a href="https://arxiv.org/ps/2108.05957">ps</a>, <a href="https://arxiv.org/format/2108.05957">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/10.1051/0004-6361/202039821">10.1051/0004-6361/202039821 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Effects of the chromospheric Ly伪 line profile shape on the determination of the solar wind HI outflow velocity using the Doppler dimming technique </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">G. E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Dolei%2C+S">S. Dolei</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">S. L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Ventura%2C+R">R. Ventura</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Frassetto%2C+F">F. Frassetto</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S+M">S. M. Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Zangrilli%2C+L">L. Zangrilli</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="2108.05957v1-abstract-short" style="display: inline;"> The determination of solar wind outflow velocity is fundamental in order to probe the mechanisms of wind acceleration in the corona. We aim to study, via the Doppler dimming technique, the effects that the chromospheric Ly伪 line profile shape causes on the determination of the outflow speed of coronal HI atoms. The Doppler dimming technique takes into account the decrease of coronal Ly伪 radiation… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.05957v1-abstract-full').style.display = 'inline'; document.getElementById('2108.05957v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.05957v1-abstract-full" style="display: none;"> The determination of solar wind outflow velocity is fundamental in order to probe the mechanisms of wind acceleration in the corona. We aim to study, via the Doppler dimming technique, the effects that the chromospheric Ly伪 line profile shape causes on the determination of the outflow speed of coronal HI atoms. The Doppler dimming technique takes into account the decrease of coronal Ly伪 radiation in regions where HI atoms flow out in the solar wind. Starting from UV observations (UVCS/SOHO) of the coronal Ly伪 line and simultaneous measurements of pB (LASCO/SOHO and Mk3/MLSO), we studied the effect of the pumping chromospheric Ly伪 line profile through measurements from SOHO/SUMER, UVSP/SMM and LPSP/OSO-8, taken from representative on-disk regions and as a function of time during the solar activity cycle. In particular, we considered the effect of four chromospheric line parameters: line width, depth of the central reversal, asymmetry and distance of the peaks. We find that the range of variability of these parameters is of about 50% for the width, 69% for the depth of the central reversal, 35% for the asymmetry, and 50% for the distance of the peaks. Then, we find that the variability of the pumping Ly伪 profile affects the estimates of the coronal HI velocity by about 9-12%. Therefore, this uncertainty is smaller than other physical quantities uncertainties, and a constant in time and unique shape of the Ly伪 profile over the solar disk can be adopted in order to estimate the solar wind outflow velocity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.05957v1-abstract-full').style.display = 'none'; document.getElementById('2108.05957v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">12 pages, 10 figures, 1 table, it will appear in "Astronomy & Astrophysics", accepted for "ESPM-16" and "SWICo 2021", the uploaded abstract is abridged</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 652, A85 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.03911">arXiv:2108.03911</a> <span> [<a href="https://arxiv.org/pdf/2108.03911">pdf</a>, <a href="https://arxiv.org/ps/2108.03911">ps</a>, <a href="https://arxiv.org/format/2108.03911">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/10.22323/1.395.0784">10.22323/1.395.0784 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Prospects for Galactic transient sources detection with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=L%C3%B3pez-Oramas%2C+A">A. L贸pez-Oramas</a>, <a href="/search/astro-ph?searchtype=author&query=Bulgarelli%2C+A">A. Bulgarelli</a>, <a href="/search/astro-ph?searchtype=author&query=Chaty%2C+S">S. Chaty</a>, <a href="/search/astro-ph?searchtype=author&query=Chernyakova%2C+M">M. Chernyakova</a>, <a href="/search/astro-ph?searchtype=author&query=Gnatyk%2C+R">R. Gnatyk</a>, <a href="/search/astro-ph?searchtype=author&query=Hnatyk%2C+B">B. Hnatyk</a>, <a href="/search/astro-ph?searchtype=author&query=Kantzas%2C+D">D. Kantzas</a>, <a href="/search/astro-ph?searchtype=author&query=Markoff%2C+S">S. Markoff</a>, <a href="/search/astro-ph?searchtype=author&query=McKeague%2C+S">S. McKeague</a>, <a href="/search/astro-ph?searchtype=author&query=Mereghetti%2C+S">S. Mereghetti</a>, <a href="/search/astro-ph?searchtype=author&query=Mestre%2C+E">E. Mestre</a>, <a href="/search/astro-ph?searchtype=author&query=di+Piano%2C+A">A. di Piano</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sadeh%2C+I">I. Sadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Sergijenko%2C+O">O. Sergijenko</a>, <a href="/search/astro-ph?searchtype=author&query=Sidoli%2C+L">L. Sidoli</a>, <a href="/search/astro-ph?searchtype=author&query=Spolon%2C+A">A. Spolon</a>, <a href="/search/astro-ph?searchtype=author&query=Wilhelmi%2C+E+d+O">E. de O帽a Wilhelmi</a>, <a href="/search/astro-ph?searchtype=author&query=Piano%2C+G">G. Piano</a>, <a href="/search/astro-ph?searchtype=author&query=Zampieri%2C+L">L. Zampieri</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="2108.03911v1-abstract-short" style="display: inline;"> Several types of Galactic sources, like magnetars, microquasars, novae or pulsar wind nebulae flares, display transient emission in the X-ray band. Some of these sources have also shown emission at MeV--GeV energies. However, none of these Galactic transients have ever been detected in the very-high-energy (VHE; E$>$100 GeV) regime by any Imaging Air Cherenkov Telescope (IACT). The Galactic Transi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.03911v1-abstract-full').style.display = 'inline'; document.getElementById('2108.03911v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.03911v1-abstract-full" style="display: none;"> Several types of Galactic sources, like magnetars, microquasars, novae or pulsar wind nebulae flares, display transient emission in the X-ray band. Some of these sources have also shown emission at MeV--GeV energies. However, none of these Galactic transients have ever been detected in the very-high-energy (VHE; E$>$100 GeV) regime by any Imaging Air Cherenkov Telescope (IACT). The Galactic Transient task force is a part of the Transient Working group of the Cherenkov Telescope Array (CTA) Consortium. The task force investigates the prospects of detecting the VHE counterpart of such sources, as well as their study following Target of Opportunity (ToO) observations. In this contribution, we will show some of the results of exploring the capabilities of CTA to detect and observe Galactic transients; we assume different array configurations and observing strategies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.03911v1-abstract-full').style.display = 'none'; document.getElementById('2108.03911v1-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 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">37th International Cosmic Ray Conference (ICRC2021)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.13223">arXiv:2107.13223</a> <span> [<a href="https://arxiv.org/pdf/2107.13223">pdf</a>, <a href="https://arxiv.org/format/2107.13223">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> The CoMET multiperspective event tracker for wide field-of-view gamma-ray astronomy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=CoMET+Collaboration"> CoMET Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Mezek%2C+G+K">Ga拧per Kukec Mezek</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Yvonne Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">Tomas Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Ernenwein%2C+J">Jean-Pierre Ernenwein</a>, <a href="/search/astro-ph?searchtype=author&query=Punch%2C+M">Michael Punch</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Patrizia Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Saleh%2C+A">Ahmed Saleh</a>, <a href="/search/astro-ph?searchtype=author&query=Senniappan%2C+M">Mohanraj Senniappan</a>, <a href="/search/astro-ph?searchtype=author&query=Thoudam%2C+S">Satyendra Thoudam</a>, <a href="/search/astro-ph?searchtype=author&query=Tluczykont%2C+M">Martin Tluczykont</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">Stefano Vercellone</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="2107.13223v1-abstract-short" style="display: inline;"> The CoMET R&D project focuses on the development of a new technique for the observation of very high-energy (VHE) $纬$-rays from the ground at energies above ~200 GeV, thus covering emission from soft-spectrum sources. The CoMET array under study combines 1242 particle detector units, distributed over a circular area of ~160 m in diameter and placed at a very high altitude (5.1 km), with atmospheri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.13223v1-abstract-full').style.display = 'inline'; document.getElementById('2107.13223v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.13223v1-abstract-full" style="display: none;"> The CoMET R&D project focuses on the development of a new technique for the observation of very high-energy (VHE) $纬$-rays from the ground at energies above ~200 GeV, thus covering emission from soft-spectrum sources. The CoMET array under study combines 1242 particle detector units, distributed over a circular area of ~160 m in diameter and placed at a very high altitude (5.1 km), with atmospheric Cherenkov light detectors. The atmospheric Cherenkov light detectors, inspired by the "HiSCORE" design and improved for the energy range of interest, can be operated together with the particle detectors during clear nights. As such, the instrument becomes a Cosmic Multiperspective Event Tracker (CoMET). CoMET is expected to improve the reconstruction of arrival direction, energy and shower maximum determination for $纬$-ray-induced showers during darkness, which is crucial for the reduction of background contamination from cosmic rays. Prototypes of both particle and atmospheric Cherenkov light detectors are already installed at Linnaeus University in Sweden, while in parallel we simulate the full detector response and estimate the reconstruction improvement for $纬$-ray events. In this contribution, we present Monte-Carlo simulations of the detector array, consisting of CORSIKA shower simulations and custom detector response simulations, together with the coupling of particle and atmospheric Cherenkov light information, the reconstruction strategy of the complete array and the detection performance on point-like VHE $纬$-ray sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.13223v1-abstract-full').style.display = 'none'; document.getElementById('2107.13223v1-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, 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">9 pages, 4 figures, Proceedings of the 37th International Cosmic Ray Conference (ONLINE ICRC2021), Berlin (Germany)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.13344">arXiv:2106.13344</a> <span> [<a href="https://arxiv.org/pdf/2106.13344">pdf</a>, <a href="https://arxiv.org/format/2106.13344">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/10.1051/0004-6361/202140980">10.1051/0004-6361/202140980 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First light observations of the solar wind in the outer corona with the Metis coronagraph </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">G. E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">C. Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">A. Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">L. Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Y+M">Y. M. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">G. Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">M. Casti</a>, <a href="/search/astro-ph?searchtype=author&query=Fabi%2C+M">M. Fabi</a> , et al. (43 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="2106.13344v1-abstract-short" style="display: inline;"> The investigation of the wind in the solar corona initiated with the observations of the resonantly scattered UV emission of the coronal plasma obtained with UVCS-SOHO, designed to measure the wind outflow speed by applying the Doppler dimming diagnostics. Metis on Solar Orbiter complements the UVCS spectroscopic observations, performed during solar activity cycle 23, by simultaneously imaging the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13344v1-abstract-full').style.display = 'inline'; document.getElementById('2106.13344v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.13344v1-abstract-full" style="display: none;"> The investigation of the wind in the solar corona initiated with the observations of the resonantly scattered UV emission of the coronal plasma obtained with UVCS-SOHO, designed to measure the wind outflow speed by applying the Doppler dimming diagnostics. Metis on Solar Orbiter complements the UVCS spectroscopic observations, performed during solar activity cycle 23, by simultaneously imaging the polarized visible light and the HI Ly-alpha corona in order to obtain high-spatial and temporal resolution maps of the outward velocity of the continuously expanding solar atmosphere. The Metis observations, on May 15, 2020, provide the first HI Ly-alpha images of the extended corona and the first instantaneous map of the speed of the coronal plasma outflows during the minimum of solar activity and allow us to identify the layer where the slow wind flow is observed. The polarized visible light (580-640 nm), and the UV HI Ly-alpha (121.6 nm) coronal emissions, obtained with the two Metis channels, are combined in order to measure the dimming of the UV emission relative to a static corona. This effect is caused by the outward motion of the coronal plasma along the direction of incidence of the chromospheric photons on the coronal neutral hydrogen. The plasma outflow velocity is then derived as a function of the measured Doppler dimming. The static corona UV emission is simulated on the basis of the plasma electron density inferred from the polarized visible light. This study leads to the identification, in the velocity maps of the solar corona, of the high-density layer about +/-10 deg wide, centered on the extension of a quiet equatorial streamer present at the East limb where the slowest wind flows at about (160 +/- 18) km/s from 4 Rs to 6 Rs. Beyond the boundaries of the high-density layer, the wind velocity rapidly increases, marking the transition between slow and fast wind in the corona. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13344v1-abstract-full').style.display = 'none'; document.getElementById('2106.13344v1-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, 2021, Forthcoming article </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.12536">arXiv:2106.12536</a> <span> [<a href="https://arxiv.org/pdf/2106.12536">pdf</a>, <a href="https://arxiv.org/format/2106.12536">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/10.1051/0004-6361/202141409">10.1051/0004-6361/202141409 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Hunting for the nature of the enigmatic narrow-line Seyfert 1 galaxy PKS 2004-447 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Berton%2C+M">M. Berton</a>, <a href="/search/astro-ph?searchtype=author&query=Peluso%2C+G">G. Peluso</a>, <a href="/search/astro-ph?searchtype=author&query=Marziani%2C+P">P. Marziani</a>, <a href="/search/astro-ph?searchtype=author&query=Komossa%2C+S">S. Komossa</a>, <a href="/search/astro-ph?searchtype=author&query=Foschini%2C+L">L. Foschini</a>, <a href="/search/astro-ph?searchtype=author&query=Ciroi%2C+S">S. Ciroi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S">S. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Congiu%2C+E">E. Congiu</a>, <a href="/search/astro-ph?searchtype=author&query=Gallo%2C+L+C">L. C. Gallo</a>, <a href="/search/astro-ph?searchtype=author&query=Bj%C3%B6rklund%2C+I">I. Bj枚rklund</a>, <a href="/search/astro-ph?searchtype=author&query=Crepaldi%2C+L">L. Crepaldi</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Mille%2C+F">F. Di Mille</a>, <a href="/search/astro-ph?searchtype=author&query=J%C3%A4rvel%C3%A4%2C+E">E. J盲rvel盲</a>, <a href="/search/astro-ph?searchtype=author&query=Kotilainen%2C+J">J. Kotilainen</a>, <a href="/search/astro-ph?searchtype=author&query=Kreikenbohm%2C+A">A. Kreikenbohm</a>, <a href="/search/astro-ph?searchtype=author&query=Morrell%2C+N">N. Morrell</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sani%2C+E">E. Sani</a>, <a href="/search/astro-ph?searchtype=author&query=Terreran%2C+G">G. Terreran</a>, <a href="/search/astro-ph?searchtype=author&query=Tornikoski%2C+M">M. Tornikoski</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Vietri%2C+A">A. Vietri</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="2106.12536v2-abstract-short" style="display: inline;"> Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that, in some cases, can harbor powerful relativistic jets. One of them, PKS 2004-447, shows gamma-ray emission, and underwent its first recorded multifrequency flare in 2019. However, past studies revealed that in radio this source can be classified as a compact steep-spectrum source (CSS), suggesting that, unlike o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.12536v2-abstract-full').style.display = 'inline'; document.getElementById('2106.12536v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.12536v2-abstract-full" style="display: none;"> Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that, in some cases, can harbor powerful relativistic jets. One of them, PKS 2004-447, shows gamma-ray emission, and underwent its first recorded multifrequency flare in 2019. However, past studies revealed that in radio this source can be classified as a compact steep-spectrum source (CSS), suggesting that, unlike other gamma-ray sources, the relativistic jets of PKS 2004-447 have a large inclination with respect to the line of sight. We present here a set of spectroscopic observations of this object, aimed at carefully measuring its black hole mass and Eddington ratio, determining the properties of its emission lines, and characterizing its long term variability. We find that the black hole mass is $(1.5\pm0.2)\times10^7$ M$_\odot$, and the Eddington ratio is 0.08. Both values are within the typical range of NLS1s. The spectra also suggest that the 2019 flare was caused mainly by the relativistic jet, while the accretion disk played a minor role during the event. In conclusion, we confirm that PKS 2004-447 is one of the rare examples of gamma-ray emitting CSS/NLS1s hybrid, and that these two classes of objects are likely connected in the framework of AGN evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.12536v2-abstract-full').style.display = 'none'; document.getElementById('2106.12536v2-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 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">14 pages, 8 figures, 4 tables, resubmitted to A&A after minor comments from the referee</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 654, A125 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.11638">arXiv:2106.11638</a> <span> [<a href="https://arxiv.org/pdf/2106.11638">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-021-26981-7">10.1038/s41467-021-26981-7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Direct evidence: twisted flux tube emergence creates solar active regions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=MacTaggart%2C+D">David MacTaggart</a>, <a href="/search/astro-ph?searchtype=author&query=Prior%2C+C">Chris Prior</a>, <a href="/search/astro-ph?searchtype=author&query=Raphaldini%2C+B">Breno Raphaldini</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Paolo Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S">Salvatore Guglielmino</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="2106.11638v1-abstract-short" style="display: inline;"> The magnetic nature of the formation of solar active regions lies at the heart of understanding solar activity and, in particular, solar eruptions. A widespread model, used in many theoretical studies, simulations and the interpretation of observations is that the basic structure of an active region is created by the emergence of a large tube of pre-twisted magnetic field. Despite plausible reason… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.11638v1-abstract-full').style.display = 'inline'; document.getElementById('2106.11638v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.11638v1-abstract-full" style="display: none;"> The magnetic nature of the formation of solar active regions lies at the heart of understanding solar activity and, in particular, solar eruptions. A widespread model, used in many theoretical studies, simulations and the interpretation of observations is that the basic structure of an active region is created by the emergence of a large tube of pre-twisted magnetic field. Despite plausible reasons and the availability of various proxies suggesting the veracity of this model, there has not yet been any direct observational evidence of the emergence of large twisted magnetic flux tubes. Thus, the fundamental question, "are active regions formed by large twisted flux tubes?" has remained open. In this work, we answer this question in the affirmative and provide direct evidence to support this. We do this by investigating a robust topological quantity, called magnetic winding, in solar observations. This quantity, combined with other signatures that are currently available, provides the first direct evidence that large twisted flux tubes do emerge to create active regions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.11638v1-abstract-full').style.display = 'none'; document.getElementById('2106.11638v1-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.08952">arXiv:2106.08952</a> <span>  </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="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Feedback on the ASTRONET Science Vision and Infrastructure Roadmap from the CTA Consortium </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Araudo%2C+A">A. Araudo</a>, <a href="/search/astro-ph?searchtype=author&query=Carosi%2C+A">A. Carosi</a>, <a href="/search/astro-ph?searchtype=author&query=Hofmann%2C+W">W. Hofmann</a>, <a href="/search/astro-ph?searchtype=author&query=Iocco%2C+F">F. Iocco</a>, <a href="/search/astro-ph?searchtype=author&query=Lenain%2C+J+-">J. -P. Lenain</a>, <a href="/search/astro-ph?searchtype=author&query=Lindfors%2C+E">E. Lindfors</a>, <a href="/search/astro-ph?searchtype=author&query=Lopez%2C+A">A. Lopez</a>, <a href="/search/astro-ph?searchtype=author&query=Meyer%2C+M">M. Meyer</a>, <a href="/search/astro-ph?searchtype=author&query=Morlino%2C+G">G. Morlino</a>, <a href="/search/astro-ph?searchtype=author&query=Olmi%2C+B">B. Olmi</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Santander%2C+M">M. Santander</a>, <a href="/search/astro-ph?searchtype=author&query=Tibaldo%2C+L">L. Tibaldo</a>, <a href="/search/astro-ph?searchtype=author&query=Zanin%2C+R">R. Zanin</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="2106.08952v1-abstract-short" style="display: inline;"> Feedback on the ASTRONET Science Vision and Infrastructure Roadmap from the CTA Consortium. </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.08952v1-abstract-full" style="display: none;"> Feedback on the ASTRONET Science Vision and Infrastructure Roadmap from the CTA Consortium. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.08952v1-abstract-full').style.display = 'none'; document.getElementById('2106.08952v1-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Submitted as input to the ASTRONET Science Vision and Infrastructure roadmap on behalf of the CTA consortium</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.05971">arXiv:2106.05971</a> <span> [<a href="https://arxiv.org/pdf/2106.05971">pdf</a>, <a href="https://arxiv.org/format/2106.05971">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="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Probing extreme environments with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A+M">A. M. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">A. Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Chernyakova%2C+M">M. Chernyakova</a>, <a href="/search/astro-ph?searchtype=author&query=Hassan%2C+T">T. Hassan</a>, <a href="/search/astro-ph?searchtype=author&query=Lenain%2C+J+-">J. -P. Lenain</a>, <a href="/search/astro-ph?searchtype=author&query=Manganaro%2C+M">M. Manganaro</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sol%2C+H">H. Sol</a>, <a href="/search/astro-ph?searchtype=author&query=Tavecchio%2C+F">F. Tavecchio</a>, <a href="/search/astro-ph?searchtype=author&query=Vercellone%2C+S">S. Vercellone</a>, <a href="/search/astro-ph?searchtype=author&query=Zampieri%2C+L">L. Zampieri</a>, <a href="/search/astro-ph?searchtype=author&query=Zanin%2C+R">R. Zanin</a>, <a href="/search/astro-ph?searchtype=author&query=Zech%2C+A">A. Zech</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Anguner%2C+E+O">E. O. Anguner</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=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Balazs%2C+C">C. Balazs</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=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=Bissaldi%2C+E">E. Bissaldi</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</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="2106.05971v1-abstract-short" style="display: inline;"> The physics of the non-thermal Universe provides information on the acceleration mechanisms in extreme environments, such as black holes and relativistic jets, neutron stars, supernovae or clusters of galaxies. In the presence of magnetic fields, particles can be accelerated towards relativistic energies. As a consequence, radiation along the entire electromagnetic spectrum can be observed, and ex… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.05971v1-abstract-full').style.display = 'inline'; document.getElementById('2106.05971v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.05971v1-abstract-full" style="display: none;"> The physics of the non-thermal Universe provides information on the acceleration mechanisms in extreme environments, such as black holes and relativistic jets, neutron stars, supernovae or clusters of galaxies. In the presence of magnetic fields, particles can be accelerated towards relativistic energies. As a consequence, radiation along the entire electromagnetic spectrum can be observed, and extreme environments are also the most likely sources of multi-messenger emission. The most energetic part of the electromagnetic spectrum corresponds to the very-high-energy (VHE, E>100 GeV) gamma-ray regime, which can be extensively studied with ground based Imaging Atmospheric Cherenkov Telescopes (IACTs). The results obtained by the current generation of IACTs, such as H.E.S.S., MAGIC, and VERITAS, demonstrate the crucial importance of the VHE band in understanding the non-thermal emission of extreme environments in our Universe. In some objects, the energy output in gamma rays can even outshine the rest of the broadband spectrum. The Cherenkov Telescope Array (CTA) is the next generation of IACTs, which, with cutting edge technology and a strategic configuration of ~100 telescopes distributed in two observing sites, in the northern and southern hemispheres, will reach better sensitivity, angular and energy resolution, and broader energy coverage than currently operational IACTs. With CTA we can probe the most extreme environments and considerably boost our knowledge of the non-thermal Universe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.05971v1-abstract-full').style.display = 'none'; document.getElementById('2106.05971v1-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Submitted as input to ASTRONET Science Vision and Infrastructure roadmap on behalf of the CTA consortium</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.04936">arXiv:2106.04936</a> <span> [<a href="https://arxiv.org/pdf/2106.04936">pdf</a>, <a href="https://arxiv.org/ps/2106.04936">ps</a>, <a href="https://arxiv.org/format/2106.04936">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/10.1051/0004-6361/202141034">10.1051/0004-6361/202141034 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Penumbral decay observed in active region NOAA 12585 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Murabito%2C+M">M. Murabito</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S+L">S. L. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Ermolli%2C+I">I. Ermolli</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Jafarzadeh%2C+S">S. Jafarzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=van+der+Voort%2C+L+H+M+R">L. H. M. Rouppe van der Voort</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="2106.04936v1-abstract-short" style="display: inline;"> The physical conditions leading the sunspot penumbra decay are poorly understood so far. We investigate the photospheric magnetic and velocity properties of a sunspot penumbra during the decay phase to advance the current knowledge of the conditions leading to this process. A penumbral decay was observed with the CRISP instrument at the Swedish 1m Solar Telescope on 2016 September 4 and 5 in activ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.04936v1-abstract-full').style.display = 'inline'; document.getElementById('2106.04936v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.04936v1-abstract-full" style="display: none;"> The physical conditions leading the sunspot penumbra decay are poorly understood so far. We investigate the photospheric magnetic and velocity properties of a sunspot penumbra during the decay phase to advance the current knowledge of the conditions leading to this process. A penumbral decay was observed with the CRISP instrument at the Swedish 1m Solar Telescope on 2016 September 4 and 5 in active region NOAA 12585. During these days, full-Stokes spectropolarimetric scans along the Fe I 630 nm line pair were acquired over more than one hour. We inverted these observations with the VFISV code in order to obtain the evolution of the magnetic and velocity properties. We complement the study with data from instruments onboard the Solar Dynamics Observatory and Hinode space missions. The studied penumbra disappears progressively in both time and space. The magnetic flux evolution seems to be linked to the presence of Moving Magnetic Features (MMFs). Decreasing Stokes V signals are observed. Evershed flows and horizontal fields were detected even after the disappearance of the penumbral sector. The analyzed penumbral decay seems to result from the interaction between opposite polarity fields in type III MMFs and penumbra, while the presence of overlying canopies rules the evolution in the different penumbral sectors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.04936v1-abstract-full').style.display = 'none'; document.getElementById('2106.04936v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">13 pages, 11 figures, accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 653, A93 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.03621">arXiv:2106.03621</a> <span> [<a href="https://arxiv.org/pdf/2106.03621">pdf</a>, <a href="https://arxiv.org/format/2106.03621">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> <p class="title is-5 mathjax"> Multi-messenger and transient astrophysics with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bo%C5%A1njak%2C+%C5%BD">沤. Bo拧njak</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A+M">A. M. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Carosi%2C+A">A. Carosi</a>, <a href="/search/astro-ph?searchtype=author&query=Chernyakova%2C+M">M. Chernyakova</a>, <a href="/search/astro-ph?searchtype=author&query=Cristofari%2C+P">P. Cristofari</a>, <a href="/search/astro-ph?searchtype=author&query=Longo%2C+F">F. Longo</a>, <a href="/search/astro-ph?searchtype=author&query=L%C3%B3pez-Oramas%2C+A">A. L贸pez-Oramas</a>, <a href="/search/astro-ph?searchtype=author&query=Santander%2C+M">M. Santander</a>, <a href="/search/astro-ph?searchtype=author&query=Satalecka%2C+K">K. Satalecka</a>, <a href="/search/astro-ph?searchtype=author&query=Sch%C3%BCssler%2C+F">F. Sch眉ssler</a>, <a href="/search/astro-ph?searchtype=author&query=Sergijenko%2C+O">O. Sergijenko</a>, <a href="/search/astro-ph?searchtype=author&query=Stamerra%2C+A">A. Stamerra</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Anguner%2C+E+O">E. O. Anguner</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=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Balazs%2C+C">Csaba Balazs</a>, <a href="/search/astro-ph?searchtype=author&query=Baroncelli%2C+L">L. Baroncelli</a>, <a href="/search/astro-ph?searchtype=author&query=Tjus%2C+J+B">J. Becker Tjus</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=Bissaldi%2C+E">E. Bissaldi</a>, <a href="/search/astro-ph?searchtype=author&query=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a> , et al. (120 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="2106.03621v1-abstract-short" style="display: inline;"> The discovery of gravitational waves, high-energy neutrinos or the very-high-energy counterpart of gamma-ray bursts has revolutionized the high-energy and transient astrophysics community. The development of new instruments and analysis techniques will allow the discovery and/or follow-up of new transient sources. We describe the prospects for the Cherenkov Telescope Array (CTA), the next-generati… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.03621v1-abstract-full').style.display = 'inline'; document.getElementById('2106.03621v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.03621v1-abstract-full" style="display: none;"> The discovery of gravitational waves, high-energy neutrinos or the very-high-energy counterpart of gamma-ray bursts has revolutionized the high-energy and transient astrophysics community. The development of new instruments and analysis techniques will allow the discovery and/or follow-up of new transient sources. We describe the prospects for the Cherenkov Telescope Array (CTA), the next-generation ground-based gamma-ray observatory, for multi-messenger and transient astrophysics in the decade ahead. CTA will explore the most extreme environments via very-high-energy observations of compact objects, stellar collapse events, mergers and cosmic-ray accelerators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.03621v1-abstract-full').style.display = 'none'; document.getElementById('2106.03621v1-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Submitted to ASTRONET roadmap on behalf of the CTA consortium</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.03599">arXiv:2106.03599</a> <span> [<a href="https://arxiv.org/pdf/2106.03599">pdf</a>, <a href="https://arxiv.org/format/2106.03599">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> <p class="title is-5 mathjax"> Origin and role of relativistic cosmic particles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Araudo%2C+A">A. Araudo</a>, <a href="/search/astro-ph?searchtype=author&query=Morlino%2C+G">G. Morlino</a>, <a href="/search/astro-ph?searchtype=author&query=Olmi%2C+B">B. Olmi</a>, <a href="/search/astro-ph?searchtype=author&query=Acero%2C+F">F. Acero</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Adam%2C+R">R. Adam</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+R+A">R. Alves Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Anguner%2C+E+O">E. O. Anguner</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=Ascasibar%2C+Y">Y. Ascasibar</a>, <a href="/search/astro-ph?searchtype=author&query=Balazs%2C+C">C. Balazs</a>, <a href="/search/astro-ph?searchtype=author&query=Tjus%2C+J+B">J. Becker Tjus</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=Bissaldi%2C+E">E. Bissaldi</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bordas%2C+P">P. Bordas</a>, <a href="/search/astro-ph?searchtype=author&query=Bo%C5%A1njak%2C+%C5%BD">沤. Bo拧njak</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A+M">A. M. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burton%2C+M">M. Burton</a>, <a href="/search/astro-ph?searchtype=author&query=Bucciantini%2C+N">N. Bucciantini</a>, <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a>, <a href="/search/astro-ph?searchtype=author&query=Caraveo%2C+P">P. Caraveo</a>, <a href="/search/astro-ph?searchtype=author&query=Cardillo%2C+M">M. Cardillo</a> , et al. (99 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="2106.03599v2-abstract-short" style="display: inline;"> This white paper briefly summarizes the importance of the study of relativistic cosmic rays, both as a constituent of our Universe, and through their impact on stellar and galactic evolution. The focus is on what can be learned over the coming decade through ground-based gamma-ray observations over the 20 GeV to 300 TeV range. The majority of the material is drawn directly from "Science with the C… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.03599v2-abstract-full').style.display = 'inline'; document.getElementById('2106.03599v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.03599v2-abstract-full" style="display: none;"> This white paper briefly summarizes the importance of the study of relativistic cosmic rays, both as a constituent of our Universe, and through their impact on stellar and galactic evolution. The focus is on what can be learned over the coming decade through ground-based gamma-ray observations over the 20 GeV to 300 TeV range. The majority of the material is drawn directly from "Science with the Cherenkov Telescope Array", which describes the overall science case for CTA. We request that authors wishing to cite results contained in this white paper cite the original work. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.03599v2-abstract-full').style.display = 'none'; document.getElementById('2106.03599v2-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Submitted as input to ASTRONET Science Vision and Infrastructure roadmap on behalf of the CTA consortium. arXiv admin note: text overlap with arXiv:1709.07997</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.03582">arXiv:2106.03582</a> <span> [<a href="https://arxiv.org/pdf/2106.03582">pdf</a>, <a href="https://arxiv.org/format/2106.03582">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> </div> <p class="title is-5 mathjax"> Probing Dark Matter and Fundamental Physics with the Cherenkov Telescope Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Iocco%2C+F">F. Iocco</a>, <a href="/search/astro-ph?searchtype=author&query=Meyer%2C+M">M. Meyer</a>, <a href="/search/astro-ph?searchtype=author&query=Doro%2C+M">M. Doro</a>, <a href="/search/astro-ph?searchtype=author&query=Hofmann%2C+W">W. Hofmann</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A9rez-Romero%2C+J">J. P茅rez-Romero</a>, <a href="/search/astro-ph?searchtype=author&query=Zaharijas%2C+G">G. Zaharijas</a>, <a href="/search/astro-ph?searchtype=author&query=Aguirre-Santaella%2C+A">A. Aguirre-Santaella</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Anguner%2C+E+O">E. O. Anguner</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=Ascasibar%2C+Y">Y. Ascasibar</a>, <a href="/search/astro-ph?searchtype=author&query=Bal%C3%A1zs%2C+C">C. Bal谩zs</a>, <a href="/search/astro-ph?searchtype=author&query=Beck%2C+G">G. Beck</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=Bringmann%2C+T">T. Bringmann</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A+M">A. M. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Burton%2C+M+G">M. G. Burton</a>, <a href="/search/astro-ph?searchtype=author&query=Chaty%2C+M+C+S">M. Cardillo S. Chaty</a>, <a href="/search/astro-ph?searchtype=author&query=Cotter%2C+G">G. Cotter</a>, <a href="/search/astro-ph?searchtype=author&query=della+Volpe%2C+D">D. della Volpe</a>, <a href="/search/astro-ph?searchtype=author&query=Djannati-Ata%C3%AF%2C+A">A. Djannati-Ata茂</a>, <a href="/search/astro-ph?searchtype=author&query=Eckner%2C+C">C. Eckner</a>, <a href="/search/astro-ph?searchtype=author&query=Emery%2C+G">G. Emery</a>, <a href="/search/astro-ph?searchtype=author&query=Fedorova%2C+E">E. Fedorova</a> , et al. (49 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.03582v2-abstract-short" style="display: inline;"> Astrophysical observations provide strong evidence that more than 80% of all matter in the Universe is in the form of dark matter (DM). Two leading candidates of particles beyond the Standard Model that could constitute all or a fraction of the DM content are the so-called Weakly Interacting Massive Particles (WIMPs) and Axion-Like Particles (ALPs). The upcoming Cherenkov Telescope Array, which wi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.03582v2-abstract-full').style.display = 'inline'; document.getElementById('2106.03582v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.03582v2-abstract-full" style="display: none;"> Astrophysical observations provide strong evidence that more than 80% of all matter in the Universe is in the form of dark matter (DM). Two leading candidates of particles beyond the Standard Model that could constitute all or a fraction of the DM content are the so-called Weakly Interacting Massive Particles (WIMPs) and Axion-Like Particles (ALPs). The upcoming Cherenkov Telescope Array, which will observe gamma rays between 20 GeV and 300 TeV with unprecedented sensitivity, will have unique capabilities to search for these DM candidates. A particularly promising target for WIMP searches is the Galactic Center. WIMPs with annihilation cross sections correctly producing the DM relic density will be detectable with CTA, assuming an Einasto-like density profile and WIMP masses between 200 GeV and 10 TeV. Regarding new physics beyond DM, CTA observations will also enable tests of fundamental symmetries of nature such as Lorentz invariance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.03582v2-abstract-full').style.display = 'none'; document.getElementById('2106.03582v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">Submitted as input to the ASTRONET Science Vision and Infrastructure roadmap on behalf of the CTA consortium</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.13700">arXiv:2104.13700</a> <span> [<a href="https://arxiv.org/pdf/2104.13700">pdf</a>, <a href="https://arxiv.org/format/2104.13700">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/10.1051/0004-6361/202140930">10.1051/0004-6361/202140930 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Cosmic-ray flux predictions and observations for and with Metis on board Solar Orbiter </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Grimani%2C+C">C. Grimani</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Chioetto%2C+P">P. Chioetto</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fabi%2C+M">M. Fabi</a>, <a href="/search/astro-ph?searchtype=author&query=Gissot%2C+S">S. Gissot</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Persici%2C+A">A. Persici</a>, <a href="/search/astro-ph?searchtype=author&query=Plainaki%2C+C">C. Plainaki</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Sabbatini%2C+F">F. Sabbatini</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">M. Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">G. Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G">G. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">M. Casti</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Frassetto%2C+F">F. Frassetto</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a> , et al. (19 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="2104.13700v2-abstract-short" style="display: inline;"> The Metis coronagraph is one of the remote sensing instruments hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted to carry out the first simultaneous imaging of the solar corona in both visible light (VL) and ultraviolet (UV). High-energy particles penetrate spacecraft materials and may limit the performance of on-board instruments. A study of galactic cosmic-ray (GCR) tracks obs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.13700v2-abstract-full').style.display = 'inline'; document.getElementById('2104.13700v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.13700v2-abstract-full" style="display: none;"> The Metis coronagraph is one of the remote sensing instruments hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted to carry out the first simultaneous imaging of the solar corona in both visible light (VL) and ultraviolet (UV). High-energy particles penetrate spacecraft materials and may limit the performance of on-board instruments. A study of galactic cosmic-ray (GCR) tracks observed in the first VL images gathered by Metis during the commissioning phase for a total of 60 seconds of exposure time is presented here. A similar analysis is planned for the UV channel. A prediction of the GCR flux up to hundreds of GeV is made here for the first part of the Solar Orbiter mission to study the Metis coronagraph performance. GCR model predictions are compared to observations gathered on board Solar Orbiter by the EPD/HET experiment in the range 10 MeV-100 MeV in the summer 2020 and with previous measurements. Estimated cosmic-ray fluxes above 70 MeV n$^{-1}$ have been also parameterized and used for Monte Carlo simulations aiming at reproducing the cosmic-ray track observations in the Metis coronagraph VL images. The same parameterizations can also be used to study the performance of other detectors. By comparing observations of cosmic-ray tracks in the Metis VL images with FLUKA Monte Carlo simulations of cosmic-ray interactions in the VL detector, it is found that cosmic rays fire a fraction of the order of 10$^{-4}$ of the whole image pixel sample. Therefore, cosmic rays do not affect sensibly the quality of Metis VL images. It is also found that the overall efficiency for cosmic-ray identification in the Metis VL images is approximately equal to the contribution of Z$>$2 particles. As a result, the Metis coronagraph may play the role of a proton monitor for long-term GCR variations during the overall mission duration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.13700v2-abstract-full').style.display = 'none'; document.getElementById('2104.13700v2-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">11 pages, 7 figures, accepted for publication on 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 656, A15 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.01349">arXiv:2010.01349</a> <span> [<a href="https://arxiv.org/pdf/2010.01349">pdf</a>, <a href="https://arxiv.org/format/2010.01349">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1475-7516/2021/02/048">10.1088/1475-7516/2021/02/048 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Consortium%2C+T+C+T+A">The Cherenkov Telescope Array Consortium</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Abdalla%2C+H">H. Abdalla</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+H">H. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Acero%2C+F">F. Acero</a>, <a href="/search/astro-ph?searchtype=author&query=Acharyya%2C+A">A. Acharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Adam%2C+R">R. Adam</a>, <a href="/search/astro-ph?searchtype=author&query=Agudo%2C+I">I. Agudo</a>, <a href="/search/astro-ph?searchtype=author&query=Aguirre-Santaella%2C+A">A. Aguirre-Santaella</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+R">R. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+J">J. Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Alispach%2C+C">C. Alispach</a>, <a href="/search/astro-ph?searchtype=author&query=Aloisio%2C+R">R. Aloisio</a>, <a href="/search/astro-ph?searchtype=author&query=B%2C+R+A">R. Alves B</a>, <a href="/search/astro-ph?searchtype=author&query=Amati%2C+L">L. Amati</a>, <a href="/search/astro-ph?searchtype=author&query=Amato%2C+E">E. Amato</a>, <a href="/search/astro-ph?searchtype=author&query=Ambrosi%2C+G">G. Ambrosi</a>, <a href="/search/astro-ph?searchtype=author&query=Ang%C3%BCner%2C+E+O">E. O. Ang眉ner</a>, <a href="/search/astro-ph?searchtype=author&query=Araudo%2C+A">A. Araudo</a>, <a href="/search/astro-ph?searchtype=author&query=Armstrong%2C+T">T. Armstrong</a>, <a href="/search/astro-ph?searchtype=author&query=Arqueros%2C+F">F. Arqueros</a>, <a href="/search/astro-ph?searchtype=author&query=Arrabito%2C+L">L. Arrabito</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+K">K. Asano</a>, <a href="/search/astro-ph?searchtype=author&query=Ascas%C3%ADbar%2C+Y">Y. Ascas铆bar</a>, <a href="/search/astro-ph?searchtype=author&query=Ashley%2C+M">M. Ashley</a> , et al. (474 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="2010.01349v2-abstract-short" style="display: inline;"> The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for $纬$-ray astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of $纬$-ray cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nucle… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.01349v2-abstract-full').style.display = 'inline'; document.getElementById('2010.01349v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.01349v2-abstract-full" style="display: none;"> The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for $纬$-ray astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of $纬$-ray cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of $纬$-ray absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift $z=2$ and to constrain or detect $纬$-ray halos up to intergalactic-magnetic-field strengths of at least 0.3pG. Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from $纬$-ray astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of $纬$-ray cosmology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.01349v2-abstract-full').style.display = 'none'; document.getElementById('2010.01349v2-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">71 pages (including affiliations and references), 13 figures, 6 tables. Accepted in JCAP; matches published version. Corresponding authors: Jonathan Biteau, Julien Lefaucheur, Humberto Martinez-Huerta, Manuel Meyer, Santiago Pita, Ievgen Vovk</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> JCAP 02 (2021) 048 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.03244">arXiv:2009.03244</a> <span> [<a href="https://arxiv.org/pdf/2009.03244">pdf</a>, <a href="https://arxiv.org/format/2009.03244">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/10.1016/j.newar.2020.101546">10.1016/j.newar.2020.101546 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Advances in Understanding High-Mass X-ray Binaries with INTEGRAL and Future Directions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kretschmar%2C+P">Peter Kretschmar</a>, <a href="/search/astro-ph?searchtype=author&query=F%C3%BCrst%2C+F">Felix F眉rst</a>, <a href="/search/astro-ph?searchtype=author&query=Sidoli%2C+L">Lara Sidoli</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">Enrico Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Alfonso-Garz%C3%B3n%2C+J">Julia Alfonso-Garz贸n</a>, <a href="/search/astro-ph?searchtype=author&query=Bodaghee%2C+A">Arash Bodaghee</a>, <a href="/search/astro-ph?searchtype=author&query=Chaty%2C+S">Sylvain Chaty</a>, <a href="/search/astro-ph?searchtype=author&query=Chernyakova%2C+M">Masha Chernyakova</a>, <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">Carlo Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Manousakis%2C+A">Antonios Manousakis</a>, <a href="/search/astro-ph?searchtype=author&query=Negueruela%2C+I">Ignacio Negueruela</a>, <a href="/search/astro-ph?searchtype=author&query=Postnov%2C+K">Konstantin Postnov</a>, <a href="/search/astro-ph?searchtype=author&query=Paizis%2C+A">Adamantia Paizis</a>, <a href="/search/astro-ph?searchtype=author&query=Reig%2C+P">Pablo Reig</a>, <a href="/search/astro-ph?searchtype=author&query=Rodes-Roca%2C+J+J">Jos茅 Joaqu铆n Rodes-Roca</a>, <a href="/search/astro-ph?searchtype=author&query=Tsygankov%2C+S">Sergey Tsygankov</a>, <a href="/search/astro-ph?searchtype=author&query=Bird%2C+A+J">Antony J. Bird</a>, <a href="/search/astro-ph?searchtype=author&query=K%C3%BChnel%2C+M+B+n">Matthias Bissinger n茅 K眉hnel</a>, <a href="/search/astro-ph?searchtype=author&query=Blay%2C+P">Pere Blay</a>, <a href="/search/astro-ph?searchtype=author&query=Caballero%2C+I">Isabel Caballero</a>, <a href="/search/astro-ph?searchtype=author&query=Coe%2C+M+J">Malcolm J. Coe</a>, <a href="/search/astro-ph?searchtype=author&query=Domingo%2C+A">Albert Domingo</a>, <a href="/search/astro-ph?searchtype=author&query=Doroshenko%2C+V">Victor Doroshenko</a>, <a href="/search/astro-ph?searchtype=author&query=Ducci%2C+L">Lorenzo Ducci</a>, <a href="/search/astro-ph?searchtype=author&query=Falanga%2C+M">Maurizio Falanga</a> , et al. (26 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="2009.03244v1-abstract-short" style="display: inline;"> High mass X-ray binaries are among the brightest X-ray sources in the Milky Way, as well as in nearby Galaxies. Thanks to their highly variable emissions and complex phenomenology, they have attracted the interest of the high energy astrophysical community since the dawn of X-ray Astronomy. In more recent years, they have challenged our comprehension of physical processes in many more energy bands… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.03244v1-abstract-full').style.display = 'inline'; document.getElementById('2009.03244v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.03244v1-abstract-full" style="display: none;"> High mass X-ray binaries are among the brightest X-ray sources in the Milky Way, as well as in nearby Galaxies. Thanks to their highly variable emissions and complex phenomenology, they have attracted the interest of the high energy astrophysical community since the dawn of X-ray Astronomy. In more recent years, they have challenged our comprehension of physical processes in many more energy bands, ranging from the infrared to very high energies. In this review, we provide a broad but concise summary of the physical processes dominating the emission from high mass X-ray binaries across virtually the whole electromagnetic spectrum. These comprise the interaction of stellar winds with the high gravitational and magnetic fields of compact objects, the behaviour of matter under extreme magnetic and gravity conditions, and the perturbation of the massive star evolutionary processes by presence in a binary system. We highlight the role of the INTEGRAL mission in the discovery of many of the most interesting objects in the high mass X-ray binary class and its contribution in reviving the interest for these sources over the past two decades. We show how the INTEGRAL discoveries have not only contributed to significantly increase the number of high mass X-ray binaries known, thus advancing our understanding of the population as a whole, but also have opened new windows of investigation that stimulated the multi-wavelength approach nowadays common in most astrophysical research fields. We conclude the review by providing an overview of future facilities being planned from the X-ray to the very high energy domain that will hopefully help us in finding an answer to the many questions left open after more than 18 years of INTEGRAL scientific observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.03244v1-abstract-full').style.display = 'none'; document.getElementById('2009.03244v1-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 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">61 pages, 22 figures, 1 table, will be published in New Astronomy Reviews</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2008.04657">arXiv:2008.04657</a> <span> [<a href="https://arxiv.org/pdf/2008.04657">pdf</a>, <a href="https://arxiv.org/format/2008.04657">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/10.1051/0004-6361/202038278">10.1051/0004-6361/202038278 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Monitoring clumpy wind accretion in supergiant fast X-ray transients with XMM-Newto </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ferrigno%2C+C">Carlo Ferrigno</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">Enrico Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">Patrizia Romano</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2008.04657v1-abstract-short" style="display: inline;"> Supergiant fast X-ray transients (SFXTs) are a sub-class of supergiant high mass X-ray binaries hosting a neutron star accreting from the stellar wind of a massive OB companion. Compared to the classical systems, SFXTs display a pronounced variability in X-rays that has long been (at least partly) ascribed to the presence of clumps in the stellar wind. We report here on the first set of results of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.04657v1-abstract-full').style.display = 'inline'; document.getElementById('2008.04657v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.04657v1-abstract-full" style="display: none;"> Supergiant fast X-ray transients (SFXTs) are a sub-class of supergiant high mass X-ray binaries hosting a neutron star accreting from the stellar wind of a massive OB companion. Compared to the classical systems, SFXTs display a pronounced variability in X-rays that has long been (at least partly) ascribed to the presence of clumps in the stellar wind. We report here on the first set of results of an on-going XMM-Newton observational program aimed at searching for spectroscopic variability during the X-ray flares and outbursts of the SFXTs. The goal of the paper is to present the observational program and show that the obtained results are according to expectations, with a number of flares (between one and four) generally observed per source and per observation (20~ks-long, on average). We base our work on a systematic and uniform analysis method optimized to consistently search for spectral signatures of a variable absorption column density, as well as other parameters of the spectral continuum. Our preliminary results show that the program is successful and the outcomes of the analysis support previous findings that most of the X-ray flares seem associated to the presence of a massive structure approaching and getting accreted by the compact object. However, we cannot rule out that other mechanisms are at work together with clumps to enhance the X-ray variability of SFXTs. This is expected according to current theoretical models. The success of these observations shows that our observational program can be a powerful instrument to deepen our understanding of the X-ray variability in SFXTs. Further observations will help us in achieving a statistically robust sample. This is required to conduct, in the future, a systematic analysis on the whole SFXT class with the ultimate goal of disentangling the role of different mechanisms giving rise to these events. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.04657v1-abstract-full').style.display = 'none'; document.getElementById('2008.04657v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication on A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 642, A73 (2020) </p> </li> </ol> <nav 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