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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.08189">arXiv:2411.08189</a> <span> [<a href="https://arxiv.org/pdf/2411.08189">pdf</a>, <a href="https://arxiv.org/format/2411.08189">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/10.1103/PhysRevLett.133.221001">10.1103/PhysRevLett.133.221001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bouyahiaoui%2C+M">M. Bouyahiaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A">A. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a> , et al. (123 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="2411.08189v1-abstract-short" style="display: inline;"> Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.08189v1-abstract-full').style.display = 'inline'; document.getElementById('2411.08189v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.08189v1-abstract-full" style="display: none;"> Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System (H.E.S.S.), covering two orders of magnitude in energy and reaching a proton rejection power of better than $10^{4}$. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from $螕_1 = 3.25$ $\pm$ 0.02 (stat) $\pm$ 0.2 (sys) to $螕_2 = 4.49$ $\pm$ 0.04 (stat) $\pm$ 0.2 (sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.08189v1-abstract-full').style.display = 'none'; document.getElementById('2411.08189v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">main paper: 8 pages, 4 figures, supplemental material: 12 pages, 14 figures, accepted for publication in Physical Review Letters https://journals.aps.org/prl/</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 133, 221001 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.12608">arXiv:2403.12608</a> <span> [<a href="https://arxiv.org/pdf/2403.12608">pdf</a>, <a href="https://arxiv.org/format/2403.12608">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/10.1051/0004-6361/202348651">10.1051/0004-6361/202348651 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <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=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A">A. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a> , et al. (137 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="2403.12608v2-abstract-short" style="display: inline;"> The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy $纬$ rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's $纬$-ray emission between 1 GeV and $\sim$100 TeV, that is… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.12608v2-abstract-full').style.display = 'inline'; document.getElementById('2403.12608v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.12608v2-abstract-full" style="display: none;"> The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy $纬$ rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's $纬$-ray emission between 1 GeV and $\sim$100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing $纬$-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.12608v2-abstract-full').style.display = 'none'; document.getElementById('2403.12608v2-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 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 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">18+6 pages, 15+2 figures. Accepted for publication in A&A. Corresponding authors: M. Meyer, L. Mohrmann, T. Unbehaun. v2: after A&A language editing</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 686, A308 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.13330">arXiv:2402.13330</a> <span> [<a href="https://arxiv.org/pdf/2402.13330">pdf</a>, <a href="https://arxiv.org/format/2402.13330">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/10.1051/0004-6361/202348913">10.1051/0004-6361/202348913 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Curvature in the very-high energy gamma-ray spectrum of M87 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+T+B+C">T. Bulik C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a>, <a href="/search/astro-ph?searchtype=author&query=Cecil%2C+R">R. Cecil</a>, <a href="/search/astro-ph?searchtype=author&query=Celic%2C+J">J. Celic</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a> , et al. (110 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="2402.13330v3-abstract-short" style="display: inline;"> The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2$\,$ hours the H.E.S.S. observations. Our findi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.13330v3-abstract-full').style.display = 'inline'; document.getElementById('2402.13330v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.13330v3-abstract-full" style="display: none;"> The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2$\,$ hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3$\,$TeV at the 4$蟽$ level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4$\,$$渭$m - 40$\,$$渭$m. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.13330v3-abstract-full').style.display = 'none'; document.getElementById('2402.13330v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 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">10 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Rahul Cecil, Iryna Lypova, Manuel Meyer, Perri Zilberman. Supplementary material: https://zenodo.org/records/10781524</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, 685, A96 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.16019">arXiv:2401.16019</a> <span> [<a href="https://arxiv.org/pdf/2401.16019">pdf</a>, <a href="https://arxiv.org/format/2401.16019">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/10.1126/science.adi2048">10.1126/science.adi2048 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bouyahiaou%2C+M">M. Bouyahiaou</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhau%2C+M">M. Breuhau</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</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=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a> , et al. (140 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="2401.16019v1-abstract-short" style="display: inline;"> SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent shift in the apparent position of the gamma-ray emission of the parsec-scale jets. These observations trace the energetic electron population and indicate the gamma rays are produced by inverse-Compton… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16019v1-abstract-full').style.display = 'inline'; document.getElementById('2401.16019v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.16019v1-abstract-full" style="display: none;"> SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent shift in the apparent position of the gamma-ray emission of the parsec-scale jets. These observations trace the energetic electron population and indicate the gamma rays are produced by inverse-Compton scattering. Modelling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system at distances of 25 to 30 parsecs and conclude that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16019v1-abstract-full').style.display = 'none'; document.getElementById('2401.16019v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 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">Submitted 20th Apr. 2023, published 25th January 2024 (accepted version)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science383,402-406(2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.07071">arXiv:2401.07071</a> <span> [<a href="https://arxiv.org/pdf/2401.07071">pdf</a>, <a href="https://arxiv.org/format/2401.07071">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"> TeV flaring activity of the AGN PKS 0625-354 in November 2018 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <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=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Barnard%2C+J">J. Barnard</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+A">A. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a> , et al. (117 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="2401.07071v1-abstract-short" style="display: inline;"> Most $纬$-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of the object PKS 0625-354, its $纬$-ray flux and spectral variability and its broad-band spectral emission with observations from H.E.S.S., Fermi-LAT, Swift-XRT, and U… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.07071v1-abstract-full').style.display = 'inline'; document.getElementById('2401.07071v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.07071v1-abstract-full" style="display: none;"> Most $纬$-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of the object PKS 0625-354, its $纬$-ray flux and spectral variability and its broad-band spectral emission with observations from H.E.S.S., Fermi-LAT, Swift-XRT, and UVOT taken in November 2018. The H.E.S.S. light curve above 200 GeV shows an outburst in the first night of observations followed by a declining flux with a halving time scale of 5.9h. The $纬纬$-opacity constrains the upper limit of the angle between the jet and the line of sight to $\sim10^\circ$. The broad-band spectral energy distribution shows two humps and can be well fitted with a single-zone synchrotron self Compton emission model. We conclude that PKS 0625-354, as an object showing clear features of both blazars and radio galaxies, can be classified as an intermediate active galactic nuclei. Multi-wavelength studies of such intermediate objects exhibiting features of both blazars and radio galaxies are sparse but crucial for the understanding of the broad-band emission of $纬$-ray detected active galactic nuclei in general. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.07071v1-abstract-full').style.display = 'none'; document.getElementById('2401.07071v1-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 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">9 pages, 6 figures, accepted for publication in Astronomy & Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.06181">arXiv:2310.06181</a> <span> [<a href="https://arxiv.org/pdf/2310.06181">pdf</a>, <a href="https://arxiv.org/format/2310.06181">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/10.1038/s41550-023-02052-3">10.1038/s41550-023-02052-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery of a Radiation Component from the Vela Pulsar Reaching 20 Teraelectronvolts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+T+H+E+S+S">The H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a> , et al. (157 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="2310.06181v1-abstract-short" style="display: inline;"> Gamma-ray observations have established energetic isolated pulsars as outstanding particle accelerators and antimatter factories in the Galaxy. There is, however, no consensus regarding the acceleration mechanisms and the radiative processes at play, nor the locations where these take place. The spectra of all observed gamma-ray pulsars to date show strong cutoffs or a break above energies of a fe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.06181v1-abstract-full').style.display = 'inline'; document.getElementById('2310.06181v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.06181v1-abstract-full" style="display: none;"> Gamma-ray observations have established energetic isolated pulsars as outstanding particle accelerators and antimatter factories in the Galaxy. There is, however, no consensus regarding the acceleration mechanisms and the radiative processes at play, nor the locations where these take place. The spectra of all observed gamma-ray pulsars to date show strong cutoffs or a break above energies of a few gigaelectronvolt (GeV). Using the H.E.S.S. array of Cherenkov telescopes, we discovered a novel radiation component emerging beyond this generic GeV cutoff in the Vela pulsar's broadband spectrum. The extension of gamma-ray pulsation energies up to at least 20 teraelectronvolts (TeV) shows that Vela pulsar can accelerate particles to Lorentz factors higher than $4\times10^7$. This is an order of magnitude larger than in the case of the Crab pulsar, the only other pulsar detected in the TeV energy range. Our results challenge the state-of-the-art models for high-energy emission of pulsars while providing a new probe, i.e. the energetic multi-TeV component, for constraining the acceleration and emission processes in their extreme energy limit. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.06181v1-abstract-full').style.display = 'none'; document.getElementById('2310.06181v1-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 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">38 pages, 6 figures. This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in Nature Astronomy, Nat Astron (2023), and is available online at https://doi.org/10.1038/s41550-023-02052-3</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.06035">arXiv:2310.06035</a> <span> [<a href="https://arxiv.org/pdf/2310.06035">pdf</a>, <a href="https://arxiv.org/format/2310.06035">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </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/10.1051/0004-6361/202346863">10.1051/0004-6361/202346863 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Planetary system architectures with low-mass inner planets: Direct imaging exploration of mature systems beyond 1 au </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Desgrange%2C+C">Celia Desgrange</a>, <a href="/search/astro-ph?searchtype=author&query=Milli%2C+J">Julien Milli</a>, <a href="/search/astro-ph?searchtype=author&query=Chauvin%2C+G">Gael Chauvin</a>, <a href="/search/astro-ph?searchtype=author&query=Henning%2C+T">Thomas Henning</a>, <a href="/search/astro-ph?searchtype=author&query=Luashvili%2C+A">Anna Luashvili</a>, <a href="/search/astro-ph?searchtype=author&query=Read%2C+M">Matthew Read</a>, <a href="/search/astro-ph?searchtype=author&query=Wyatt%2C+M">Mark Wyatt</a>, <a href="/search/astro-ph?searchtype=author&query=Kennedy%2C+G">Grant Kennedy</a>, <a href="/search/astro-ph?searchtype=author&query=Burn%2C+R">Remo Burn</a>, <a href="/search/astro-ph?searchtype=author&query=Schlecker%2C+M">Martin Schlecker</a>, <a href="/search/astro-ph?searchtype=author&query=Kiefer%2C+F">Flavien Kiefer</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Orazi%2C+V">Valentina D'Orazi</a>, <a href="/search/astro-ph?searchtype=author&query=Messina%2C+S">Sergio Messina</a>, <a href="/search/astro-ph?searchtype=author&query=Rubini%2C+P">Pascal Rubini</a>, <a href="/search/astro-ph?searchtype=author&query=Lagrange%2C+A">Anne-Marie Lagrange</a>, <a href="/search/astro-ph?searchtype=author&query=Babusiaux%2C+C">Carine Babusiaux</a>, <a href="/search/astro-ph?searchtype=author&query=Matra%2C+L">Luca Matra</a>, <a href="/search/astro-ph?searchtype=author&query=Bitsch%2C+B">Bertram Bitsch</a>, <a href="/search/astro-ph?searchtype=author&query=Bonavita%2C+M">Mariangela Bonavita</a>, <a href="/search/astro-ph?searchtype=author&query=Delorme%2C+P">Philippe Delorme</a>, <a href="/search/astro-ph?searchtype=author&query=Matthews%2C+E">Elisabeth Matthews</a>, <a href="/search/astro-ph?searchtype=author&query=Palma-Bifani%2C+P">Paulina Palma-Bifani</a>, <a href="/search/astro-ph?searchtype=author&query=Vigan%2C+A">Arthur Vigan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.06035v1-abstract-short" style="display: inline;"> The discovery of planets orbiting at less than 1 au from their host star and less massive than Saturn in various exoplanetary systems revolutionized our theories of planetary formation. The fundamental question is whether these close-in low-mass planets could have formed in the inner disk interior to 1 au, or whether they formed further out in the planet-forming disk and migrated inward. Exploring… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.06035v1-abstract-full').style.display = 'inline'; document.getElementById('2310.06035v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.06035v1-abstract-full" style="display: none;"> The discovery of planets orbiting at less than 1 au from their host star and less massive than Saturn in various exoplanetary systems revolutionized our theories of planetary formation. The fundamental question is whether these close-in low-mass planets could have formed in the inner disk interior to 1 au, or whether they formed further out in the planet-forming disk and migrated inward. Exploring the role of additional giant planets in these systems may help us to pinpoint their global formation and evolution. We searched for additional substellar companions by using direct imaging in systems known to host close-in small planets. The use of direct imaging complemented by radial velocity and astrometric detection limits enabled us to explore the giant planet and brown dwarf demographics around these hosts to investigate the potential connection between both populations. We carried out a direct imaging survey with VLT/SPHERE to look for outer giant planets and brown dwarf companions in 27 systems hosting close-in low-mass planets discovered by radial velocity. Our sample is composed of very nearby (<20pc) planetary systems, orbiting G-, K-, and M-type mature (0.5-10Gyr) stellar hosts. We performed homogeneous direct imaging data reduction and analysis to search for and characterize point sources, and derived robust statistical detection limits. Of 337 point-source detections, we do not find any new bound companions. We recovered the emblematic very cool T-type brown dwarf GJ229B. Our typical sensitivities in direct imaging range from 5 to 30 MJup beyond 2 au. The non-detection of massive companions is consistent with predictions based on models of planet formation by core accretion. Our pilot study opens the way to a multi-technique approach for the exploration of very nearby exoplanetary systems with future ground-based and space observatories. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.06035v1-abstract-full').style.display = 'none'; document.getElementById('2310.06035v1-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 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">49 pages including 31 pages of appendices and references, 31 figures, A&A, accepted</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 680, A64 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.07872">arXiv:2308.07872</a> <span> [<a href="https://arxiv.org/pdf/2308.07872">pdf</a>, <a href="https://arxiv.org/format/2308.07872">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"> Target of Opportunity observations of flaring blazars with H.E.S.S.$\ $ </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=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=Chibueze%2C+O">O. Chibueze</a>, <a href="/search/astro-ph?searchtype=author&query=Davids%2C+I">I. Davids</a>, <a href="/search/astro-ph?searchtype=author&query=Dmytriiev%2C+A">A. Dmytriiev</a>, <a href="/search/astro-ph?searchtype=author&query=Grolleron%2C+G">G. Grolleron</a>, <a href="/search/astro-ph?searchtype=author&query=Jankowsky%2C+F">F. Jankowsky</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=Luashvili%2C+A">A. Luashvili</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="2308.07872v2-abstract-short" style="display: inline;"> Blazars are the most common class of TeV extragalactic emitters. In the framework of the AGN unified model, they are understood as AGNs with a relativistic jet pointing close the line of sight. They are characterized by extreme variability, observed to be as fast as minutes. These flares are usually observed at multiple wavelengths and their study require fast reaction and coordination among multi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.07872v2-abstract-full').style.display = 'inline'; document.getElementById('2308.07872v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.07872v2-abstract-full" style="display: none;"> Blazars are the most common class of TeV extragalactic emitters. In the framework of the AGN unified model, they are understood as AGNs with a relativistic jet pointing close the line of sight. They are characterized by extreme variability, observed to be as fast as minutes. These flares are usually observed at multiple wavelengths and their study require fast reaction and coordination among multiwavelength observatories. An important part of blazars observations with the H.E.S.S. array of Cherenkov telescopes is thus in the form of Target of Opportunity (ToO) observations. In this contribution the H.E.S.S. blazar ToO program is presented, with a focus on recent results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.07872v2-abstract-full').style.display = 'none'; document.getElementById('2308.07872v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 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">to appear in the proceedings of the ICRC 2023 Conference</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.01692">arXiv:2307.01692</a> <span> [<a href="https://arxiv.org/pdf/2307.01692">pdf</a>, <a href="https://arxiv.org/format/2307.01692">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </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/ace3c0">10.3847/2041-8213/ace3c0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The vanishing of the primary emission region in PKS 1510-089 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Barnard%2C+J">J. Barnard</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernloehr%2C+K">K. Bernloehr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Boettcher%2C+M">M. Boettcher</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>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bouyahiaoui%2C+M">M. Bouyahiaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</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=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a> , et al. (130 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="2307.01692v1-abstract-short" style="display: inline;"> In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01692v1-abstract-full').style.display = 'inline'; document.getElementById('2307.01692v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.01692v1-abstract-full" style="display: none;"> In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy gamma-ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy gamma-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy gamma-ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line-of-sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01692v1-abstract-full').style.display = 'none'; document.getElementById('2307.01692v1-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 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 4 figures, 6 tables; accepted for publication in ApJ Letters; corresponding authors: Joleen Barnard, Markus Boettcher, Hester Schutte, Michael Zacharias</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.17819">arXiv:2306.17819</a> <span> [<a href="https://arxiv.org/pdf/2306.17819">pdf</a>, <a href="https://arxiv.org/format/2306.17819">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"> Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Acharyya%2C+A">A. Acharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Adams%2C+C+B">C. B. Adams</a>, <a href="/search/astro-ph?searchtype=author&query=Archer%2C+A">A. Archer</a>, <a href="/search/astro-ph?searchtype=author&query=Bangale%2C+P">P. Bangale</a>, <a href="/search/astro-ph?searchtype=author&query=Bartkoske%2C+J+T">J. T. Bartkoske</a>, <a href="/search/astro-ph?searchtype=author&query=Batista%2C+P">P. Batista</a>, <a href="/search/astro-ph?searchtype=author&query=Benbow%2C+W">W. Benbow</a>, <a href="/search/astro-ph?searchtype=author&query=Brill%2C+A">A. Brill</a>, <a href="/search/astro-ph?searchtype=author&query=Buckley%2C+J+H">J. H. Buckley</a>, <a href="/search/astro-ph?searchtype=author&query=Christiansen%2C+J+L">J. L. Christiansen</a>, <a href="/search/astro-ph?searchtype=author&query=Chromey%2C+A+J">A. J. Chromey</a>, <a href="/search/astro-ph?searchtype=author&query=Errando%2C+M">M. Errando</a>, <a href="/search/astro-ph?searchtype=author&query=Falcone%2C+A">A. Falcone</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Q">Q. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Foote%2C+G+M">G. M. Foote</a>, <a href="/search/astro-ph?searchtype=author&query=Fortson%2C+L">L. Fortson</a>, <a href="/search/astro-ph?searchtype=author&query=Furniss%2C+A">A. Furniss</a>, <a href="/search/astro-ph?searchtype=author&query=Gallagher%2C+G">G. Gallagher</a>, <a href="/search/astro-ph?searchtype=author&query=Hanlon%2C+W">W. Hanlon</a>, <a href="/search/astro-ph?searchtype=author&query=Hanna%2C+D">D. Hanna</a>, <a href="/search/astro-ph?searchtype=author&query=Hervet%2C+O">O. Hervet</a>, <a href="/search/astro-ph?searchtype=author&query=Hinrichs%2C+C+E">C. E. Hinrichs</a>, <a href="/search/astro-ph?searchtype=author&query=Hoang%2C+J">J. Hoang</a>, <a href="/search/astro-ph?searchtype=author&query=Holder%2C+J">J. Holder</a>, <a href="/search/astro-ph?searchtype=author&query=Humensky%2C+T+B">T. B. Humensky</a> , et al. (185 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="2306.17819v1-abstract-short" style="display: inline;"> We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2$^\circ$ away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ra… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.17819v1-abstract-full').style.display = 'inline'; document.getElementById('2306.17819v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.17819v1-abstract-full" style="display: none;"> We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2$^\circ$ away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the gamma-ray data from Fermi -LAT, VERITAS, and H.E.S.S. require a spectral cut-off near 100 GeV. Both X-ray and gamma-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed gamma-ray spectral cut-off in both leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.17819v1-abstract-full').style.display = 'none'; document.getElementById('2306.17819v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 3 figures, accepted by 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/2306.05132">arXiv:2306.05132</a> <span> [<a href="https://arxiv.org/pdf/2306.05132">pdf</a>, <a href="https://arxiv.org/format/2306.05132">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/10.3847/2041-8213/acd777">10.3847/2041-8213/acd777 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Constraints on the intergalactic magnetic field using Fermi-LAT and H.E.S.S. blazar observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=S.%2C+H+E+S">H. E. S. S.</a>, <a href="/search/astro-ph?searchtype=author&query=Collaborations%2C+F">Fermi-LAT Collaborations</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</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=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Bouyahiaoui%2C+M">M. Bouyahiaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a>, <a href="/search/astro-ph?searchtype=author&query=Celic%2C+J">J. Celic</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Chand%2C+T">T. Chand</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+S">S. Chandra</a> , et al. (113 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="2306.05132v1-abstract-short" style="display: inline;"> Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in the universe. However, the origin, strength, and morphology of this intergalactic magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) the IGMF can be obtained from observations of high-energy g… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05132v1-abstract-full').style.display = 'inline'; document.getElementById('2306.05132v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.05132v1-abstract-full" style="display: none;"> Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in the universe. However, the origin, strength, and morphology of this intergalactic magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) the IGMF can be obtained from observations of high-energy gamma rays from distant blazars. Gamma rays interact with the extragalactic background light to produce electron-positron pairs, which can subsequently initiate electromagnetic cascades. The $纬$-ray signature of the cascade depends on the IGMF since it deflects the pairs. Here we report on a new search for this cascade emission using a combined data set from the Fermi Large Area Telescope and the High Energy Stereoscopic System. Using state-of-the-art Monte Carlo predictions for the cascade signal, our results place a lower limit on the IGMF of $B > 7.1\times10^{-16}$ G for a coherence length of 1 Mpc even when blazar duty cycles as short as 10 yr are assumed. This improves on previous lower limits by a factor of 2. For longer duty cycles of $10^4$ ($10^7$) yr, IGMF strengths below $1.8\times10^{-14}$ G ($3.9\times10^{-14}$ G) are excluded, which rules out specific models for IGMF generation in the early universe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05132v1-abstract-full').style.display = 'none'; document.getElementById('2306.05132v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 7 figures, 4 tables. Accepted for publication in ApJ Letters. Auxiliary data is provided in electronic format at https://zenodo.org/record/8014311</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJ Letters 2023, Volume 950, Number 2 950, L16 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.03919">arXiv:2306.03919</a> <span> [<a href="https://arxiv.org/pdf/2306.03919">pdf</a>, <a href="https://arxiv.org/format/2306.03919">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/stad1722">10.1093/mnras/stad1722 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Variability and evolution of the optical polarization of a sample of gamma-ray blazars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Otero-Santos%2C+J">J. Otero-Santos</a>, <a href="/search/astro-ph?searchtype=author&query=Acosta-Pulido%2C+J+A">J. A. Acosta-Pulido</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=Raiteri%2C+C+M">C. M. Raiteri</a>, <a href="/search/astro-ph?searchtype=author&query=Carnerero%2C+M+I">M. I. Carnerero</a>, <a href="/search/astro-ph?searchtype=author&query=Segura%2C+N+C">N. Castro Segura</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Mart%C3%ADn%2C+O">O. Gonz谩lez-Mart铆n</a>, <a href="/search/astro-ph?searchtype=author&query=Luashvili%2C+A">A. Luashvili</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.03919v1-abstract-short" style="display: inline;"> We present a polarization variability analysis of a sample of 26 $纬$-ray blazars monitored by the Steward Observatory between 2008 and 2018 in the optical band. We investigate the properties and long-term variability of their optical polarization, searching for differences between blazar types. We observe that BL Lac objects are typically less polarized and less variable than flat spectrum radio q… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.03919v1-abstract-full').style.display = 'inline'; document.getElementById('2306.03919v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.03919v1-abstract-full" style="display: none;"> We present a polarization variability analysis of a sample of 26 $纬$-ray blazars monitored by the Steward Observatory between 2008 and 2018 in the optical band. We investigate the properties and long-term variability of their optical polarization, searching for differences between blazar types. We observe that BL Lac objects are typically less polarized and less variable than flat spectrum radio quasars (FSRQs). Moreover, BL Lacs display a distribution of their polarization angle typically oriented in a preferential direction, contrary to the rather random distribution of FSRQs. For the latter blazar type, as well as those sources showing a bright stellar emission, we take into account the depolarizing effect introduced by the broad line region and the host galaxy on the measured polarization degree. In this sample we also observe that BL Lacs present an uncorrelated evolution of the flux and the polarization. Contrary, FSRQs show a correlation before the depolarization correction, that is lost however after considering this effect. In addition, we study the behaviour of the polarization angle, searching for angle rotations in its long-term evolution. We derive that the FSRQs studied here show rotations more frequently than BL Lac objects by a factor $\sim$1.5. During these periods we also observe a systematic decrease of the polarization fraction, as well as a marginal flux increase, not significant however to connect rotations with optical flares. We interpret these results within the extended shock-in-jet scenario, able to explain the overall features observed here for the polarization of the blazar sample. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.03919v1-abstract-full').style.display = 'none'; document.getElementById('2306.03919v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.09607">arXiv:2305.09607</a> <span> [<a href="https://arxiv.org/pdf/2305.09607">pdf</a>, <a href="https://arxiv.org/format/2305.09607">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </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/10.1051/0004-6361/202346056">10.1051/0004-6361/202346056 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</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=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a> , et al. (139 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.09607v1-abstract-short" style="display: inline;"> The origin of the gamma-ray emission from M87 is currently a matter of debate. This work aims to localize the VHE (100 GeV-100 TeV) gamma-ray emission from M87 and probe a potential extended hadronic emission component in the inner Virgo Cluster. The search for a steady and extended gamma-ray signal around M87 can constrain the cosmic-ray energy density and the pressure exerted by the cosmic rays… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.09607v1-abstract-full').style.display = 'inline'; document.getElementById('2305.09607v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.09607v1-abstract-full" style="display: none;"> The origin of the gamma-ray emission from M87 is currently a matter of debate. This work aims to localize the VHE (100 GeV-100 TeV) gamma-ray emission from M87 and probe a potential extended hadronic emission component in the inner Virgo Cluster. The search for a steady and extended gamma-ray signal around M87 can constrain the cosmic-ray energy density and the pressure exerted by the cosmic rays onto the intra-cluster medium, and allow us to investigate the role of the cosmic rays in the active galactic nucleus feedback as a heating mechanism in the Virgo Cluster. H.E.S.S. telescopes are sensitive to VHE gamma rays and have been utilized to observe M87 since 2004. We utilized a Bayesian block analysis to identify M87 emission states with H.E.S.S. observations from 2004 until 2021, dividing them into low, intermediate, and high states. Because of the causality argument, an extended ($\gtrsim$kpc) signal is allowed only in steady emission states. Hence, we fitted the morphology of the 120h low state data and found no significant gamma-ray extension. Therefore, we derived for the low state an upper limit of 58"(corresponding to $\approx$4.6kpc) in the extension of a single-component morphological model described by a rotationally symmetric 2D Gaussian model at 99.7% confidence level. Our results exclude the radio lobes ($\approx$30 kpc) as the principal component of the VHE gamma-ray emission from the low state of M87. The gamma-ray emission is compatible with a single emission region at the radio core of M87. These results, with the help of two multiple-component models, constrain the maximum cosmic-ray to thermal pressure ratio $X_{CR,max.}$$\lesssim$$0.32$ and the total energy in cosmic-ray protons (CRp) to $U_{CR}$$\lesssim$5$\times10^{58}$ erg in the inner 20kpc of the Virgo Cluster for an assumed CRp power-law distribution in momentum with spectral index $伪_{p}$=2.1. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.09607v1-abstract-full').style.display = 'none'; document.getElementById('2305.09607v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 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">15 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Stefan Ohm, Cornelia Arcaro, Natalia 呕ywucka, Mathieu de Naurois</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 675, A138 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.07443">arXiv:2305.07443</a> <span> [<a href="https://arxiv.org/pdf/2305.07443">pdf</a>, <a href="https://arxiv.org/format/2305.07443">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/stad1393">10.1093/mnras/stad1393 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Modelling the variable emission states of $纬$-ray emitting Narrow-Line Seyfert 1 galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Luashvili%2C+A">Anna Luashvili</a>, <a href="/search/astro-ph?searchtype=author&query=Boisson%2C+C">Catherine Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Zech%2C+A">Andreas Zech</a>, <a href="/search/astro-ph?searchtype=author&query=Arrieta-Lobo%2C+M">Maialen Arrieta-Lobo</a>, <a href="/search/astro-ph?searchtype=author&query=Kynoch%2C+D">Daniel Kynoch</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="2305.07443v1-abstract-short" style="display: inline;"> $纬$-ray-emitting narrow-line Seyfert 1 galaxies ($纬$-NLS1) constitute an intriguing small population of Active Galactic Nuclei with $纬$-ray emission resembling low power flat-spectrum radio quasars (FSRQ), but with differing physical properties. They are jetted, $纬… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07443v1-abstract-full').style.display = 'inline'; document.getElementById('2305.07443v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.07443v1-abstract-full" style="display: none;"> $纬$-ray-emitting narrow-line Seyfert 1 galaxies ($纬$-NLS1) constitute an intriguing small population of Active Galactic Nuclei with $纬$-ray emission resembling low power flat-spectrum radio quasars (FSRQ), but with differing physical properties. They are jetted, $纬$/radio-loud Seyfert galaxies, with relatively low black hole masses, accreting at exceptionally high, near-Eddington rates. Certain of these sources exhibit highly variable emission states on relatively short time scales, the physical origin of which remains elusive. In this work, varying emission states of two bona-fide NLS1s, 1H 0323+342 and PMN J0948+0022, and one little studied FSRQ/intermediate object, B2 0954+25A, are examined. For each source, we analyzed quasi-simultaneous multiwavelength data for different states of $纬$-ray activity and present the results of their broad-band emission modelling, taking into account all available physical constraints to limit the range of the model parameters. Two different scenarios are discussed, in the framework of a one-zone leptonic model, where the high energy emission is due to the inverse Compton scattering of the disc and broad line region (BLR) or torus photons by relativistic electrons within the jet. The transition from low to high state is well described by variations of the jet parameters, leaving the external photon fields unchanged. The parameterisation favours an emission scenario with particle injection on a stationary shock inside the jet. When considering all physical constraints, the disc & BLR scenario is preferred for all three sources. We use the multi-epoch modelling to characterize total jet powers and discuss the intrinsic nature of $纬$-NLS1 galaxies and FSRQs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07443v1-abstract-full').style.display = 'none'; document.getElementById('2305.07443v1-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.02631">arXiv:2304.02631</a> <span> [<a href="https://arxiv.org/pdf/2304.02631">pdf</a>, <a href="https://arxiv.org/format/2304.02631">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/10.1051/0004-6361/202245776">10.1051/0004-6361/202245776 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detection of extended gamma-ray emission around the Geminga pulsar with H.E.S.S </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bouyahiaoui%2C+M">M. Bouyahiaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Scheidlin%2C+C+B">C. Burger Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a> , et al. (143 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.02631v1-abstract-short" style="display: inline;"> Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar was discovered by Milagro and later confirmed by HAWC, which are both water Cherenkov detector-based experiments. However, evidence for the Geminga pulsar wind nebula in gamma rays has long evaded detection by imaging atmospheric Cherenko… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.02631v1-abstract-full').style.display = 'inline'; document.getElementById('2304.02631v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.02631v1-abstract-full" style="display: none;"> Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar was discovered by Milagro and later confirmed by HAWC, which are both water Cherenkov detector-based experiments. However, evidence for the Geminga pulsar wind nebula in gamma rays has long evaded detection by imaging atmospheric Cherenkov telescopes (IACTs) despite targeted observations. The detection of gamma-ray emission on angular scales > 2 deg poses a considerable challenge for the background estimation in IACT data analysis. With recent developments in understanding the complementary background estimation techniques of water Cherenkov and atmospheric Cherenkov instruments, the H.E.S.S. IACT array can now confirm the detection of highly extended gamma-ray emission around the Geminga pulsar with a radius of at least 3 deg in the energy range 0.5-40 TeV. We find no indications for statistically significant asymmetries or energy-dependent morphology. A flux normalisation of $(2.8\pm0.7)\times10^{-12}$ cm$^{-2}$s$^{-1}$TeV$^{-1}$ at 1 TeV is obtained within a 1 deg radius region around the pulsar. To investigate the particle transport within the halo of energetic leptons around the pulsar, we fitted an electron diffusion model to the data. The normalisation of the diffusion coefficient obtained of $D_0 = 7.6^{+1.5}_{-1.2} \times 10^{27}$ cm$^2$s$^{-1}$, at an electron energy of 100 TeV, is compatible with values previously reported for the pulsar halo around Geminga, which is considerably below the Galactic average. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.02631v1-abstract-full').style.display = 'none'; document.getElementById('2304.02631v1-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 15 figures, 7 tables. 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 673, A148 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.12855">arXiv:2303.12855</a> <span> [<a href="https://arxiv.org/pdf/2303.12855">pdf</a>, <a href="https://arxiv.org/format/2303.12855">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/10.1088/1475-7516/2023/04/040">10.1088/1475-7516/2023/04/040 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Search for the evaporation of primordial black holes with H.E.S.S </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=collaboration%2C+H+E+S+S">H. E. S. S. collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</a>, <a href="/search/astro-ph?searchtype=author&query=Aschersleben%2C+J">J. Aschersleben</a>, <a href="/search/astro-ph?searchtype=author&query=Boettcher%2C+M">M. Boettcher</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzo%2C+R">R. Batzo</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Caro%2C+S">S. Caro</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a>, <a href="/search/astro-ph?searchtype=author&query=Celic%2C+J">J. Celic</a> , et al. (124 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="2303.12855v1-abstract-short" style="display: inline;"> Primordial Black Holes (PBHs) are hypothetical black holes predicted to have been formed from density fluctuations in the early Universe. PBHs with an initial mass around $10^{14}-10^{15}$g are expected to end their evaporation at present times in a burst of particles and very-high-energy (VHE) gamma rays. Those gamma rays may be detectable by the High Energy Stereoscopic System (H.E.S.S.), an arr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12855v1-abstract-full').style.display = 'inline'; document.getElementById('2303.12855v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.12855v1-abstract-full" style="display: none;"> Primordial Black Holes (PBHs) are hypothetical black holes predicted to have been formed from density fluctuations in the early Universe. PBHs with an initial mass around $10^{14}-10^{15}$g are expected to end their evaporation at present times in a burst of particles and very-high-energy (VHE) gamma rays. Those gamma rays may be detectable by the High Energy Stereoscopic System (H.E.S.S.), an array of imaging atmospheric Cherenkov telescopes. This paper reports on the search for evaporation bursts of VHE gamma rays with H.E.S.S., ranging from 10 to 120 seconds, as expected from the final stage of PBH evaporation and using a total of 4816 hours of observations. The most constraining upper limit on the burst rate of local PBHs is $2000$ pc$^{-3}$ yr$^{-1}$ for a burst interval of 120 seconds, at the 95\% confidence level. The implication of these measurements for PBH dark matter are also discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.12855v1-abstract-full').style.display = 'none'; document.getElementById('2303.12855v1-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 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 JCAP, corresponding authors: F.Brun, J-F. Glicenstein, V. Marandon, T. Tavernier</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.13663">arXiv:2302.13663</a> <span> [<a href="https://arxiv.org/pdf/2302.13663">pdf</a>, <a href="https://arxiv.org/format/2302.13663">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/10.1051/0004-6361/202245459">10.1051/0004-6361/202245459 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> HESS J1809$-$193: a halo of escaped electrons around a pulsar wind nebula? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=Borowska%2C+J">J. Borowska</a>, <a href="/search/astro-ph?searchtype=author&query=Bouyahiaoui%2C+M">M. Bouyahiaoui</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+B">B. Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a> , et al. (130 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="2302.13663v1-abstract-short" style="display: inline;"> Context. HESS J1809$-$193 is an unassociated very-high-energy $纬$-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809$-$1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of $纬$-ray emission up to energies of $\sim$100 TeV with the HAWC observatory has… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.13663v1-abstract-full').style.display = 'inline'; document.getElementById('2302.13663v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.13663v1-abstract-full" style="display: none;"> Context. HESS J1809$-$193 is an unassociated very-high-energy $纬$-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809$-$1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of $纬$-ray emission up to energies of $\sim$100 TeV with the HAWC observatory has led to renewed interest in HESS J1809$-$193. Aims. We aim to understand the origin of the $纬$-ray emission of HESS J1809$-$193. Methods. We analysed 93.2 h of data taken on HESS J1809$-$193 above 0.27 TeV with the High Energy Stereoscopic System (H.E.S.S.), using a multi-component, three-dimensional likelihood analysis. In addition, we provide a new analysis of 12.5 yr of Fermi-LAT data above 1 GeV within the region of HESS J1809$-$193. The obtained results are interpreted in a time-dependent modelling framework. Results. For the first time, we were able to resolve the emission detected with H.E.S.S. into two components: an extended component that exhibits a spectral cut-off at $\sim$13 TeV, and a compact component that is located close to PSR J1809$-$1917 and shows no clear spectral cut-off. The Fermi-LAT analysis also revealed extended $纬$-ray emission, on scales similar to that of the extended H.E.S.S. component. Conclusions. Our modelling indicates that based on its spectrum and spatial extent, the extended H.E.S.S. component is likely caused by inverse Compton emission from old electrons that form a halo around the pulsar wind nebula. The compact component could be connected to either the pulsar wind nebula or the supernova remnant and molecular clouds. Due to its comparatively steep spectrum, modelling the Fermi-LAT emission together with the H.E.S.S. components is not straightforward. (abridged) <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.13663v1-abstract-full').style.display = 'none'; document.getElementById('2302.13663v1-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 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">14 pages, 10 figures. Accepted for publication in A&A. Corresponding authors: Vikas Joshi, Lars Mohrmann</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 672, A103 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.09785">arXiv:2209.09785</a> <span> [<a href="https://arxiv.org/pdf/2209.09785">pdf</a>, <a href="https://arxiv.org/format/2209.09785">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/stac2686">10.1093/mnras/stac2686 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Gamma-ray observations of MAXI J1820+070 during the 2018 outburst </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Abe%2C+H">H. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+S">S. Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Acciari%2C+V+A">V. A. Acciari</a>, <a href="/search/astro-ph?searchtype=author&query=Aniello%2C+T">T. Aniello</a>, <a href="/search/astro-ph?searchtype=author&query=Ansoldi%2C+S">S. Ansoldi</a>, <a href="/search/astro-ph?searchtype=author&query=Antonelli%2C+L+A">L. A. Antonelli</a>, <a href="/search/astro-ph?searchtype=author&query=Engels%2C+A+A">A. Arbet Engels</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Artero%2C+M">M. Artero</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+K">K. Asano</a>, <a href="/search/astro-ph?searchtype=author&query=Baack%2C+D">D. Baack</a>, <a href="/search/astro-ph?searchtype=author&query=Babi%C4%87%2C+A">A. Babi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Baquero%2C+A">A. Baquero</a>, <a href="/search/astro-ph?searchtype=author&query=de+Almeida%2C+U+B">U. Barres de Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Barrio%2C+J+A">J. A. Barrio</a>, <a href="/search/astro-ph?searchtype=author&query=Batkovi%C4%87%2C+I">I. Batkovi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Baxter%2C+J">J. Baxter</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+J+B">J. Becerra Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Bednarek%2C+W">W. Bednarek</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+E">E. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardos%2C+M">M. Bernardos</a>, <a href="/search/astro-ph?searchtype=author&query=Berti%2C+A">A. Berti</a>, <a href="/search/astro-ph?searchtype=author&query=Besenrieder%2C+J">J. Besenrieder</a>, <a href="/search/astro-ph?searchtype=author&query=Bhattacharyya%2C+W">W. Bhattacharyya</a>, <a href="/search/astro-ph?searchtype=author&query=Bigongiari%2C+C">C. Bigongiari</a> , et al. (418 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="2209.09785v2-abstract-short" style="display: inline;"> MAXI J1820+070 is a low-mass X-ray binary with a black hole as a compact object. This binary underwent an exceptionally bright X-ray outburst from March to October 2018, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 hours of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS expe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.09785v2-abstract-full').style.display = 'inline'; document.getElementById('2209.09785v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.09785v2-abstract-full" style="display: none;"> MAXI J1820+070 is a low-mass X-ray binary with a black hole as a compact object. This binary underwent an exceptionally bright X-ray outburst from March to October 2018, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 hours of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to ~ 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential high-energy and very-high-energy gamma-ray emitting region should be located at a distance from the black hole ranging between 10^11 and 10^13 cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.09785v2-abstract-full').style.display = 'none'; document.getElementById('2209.09785v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 5 figures. Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.10921">arXiv:2207.10921</a> <span> [<a href="https://arxiv.org/pdf/2207.10921">pdf</a>, <a href="https://arxiv.org/format/2207.10921">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/10.1051/0004-6361/202244323">10.1051/0004-6361/202244323 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A deep spectromorphological study of the $纬$-ray emission surrounding the young massive stellar cluster Westerlund 1 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Bradascio%2C+F">F. Bradascio</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Burger-Scheidlin%2C+C">C. Burger-Scheidlin</a>, <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Chand%2C+T">T. Chand</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+S">S. Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+A">A. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chibueze%2C+O">O. Chibueze</a>, <a href="/search/astro-ph?searchtype=author&query=Cristofari%2C+P">P. Cristofari</a>, <a href="/search/astro-ph?searchtype=author&query=Mbarubucyeye%2C+J+D">J. Damascene Mbarubucyeye</a>, <a href="/search/astro-ph?searchtype=author&query=Djannati-Ata%C3%AF%2C+A">A. Djannati-Ata茂</a> , et al. (134 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.10921v2-abstract-short" style="display: inline;"> Young massive stellar clusters are extreme environments and potentially provide the means for efficient particle acceleration. Indeed, they are increasingly considered as being responsible for a significant fraction of cosmic rays (CRs) accelerated within the Milky Way. Westerlund 1, the most massive known young stellar cluster in our Galaxy is a prime candidate for studying this hypothesis. While… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.10921v2-abstract-full').style.display = 'inline'; document.getElementById('2207.10921v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.10921v2-abstract-full" style="display: none;"> Young massive stellar clusters are extreme environments and potentially provide the means for efficient particle acceleration. Indeed, they are increasingly considered as being responsible for a significant fraction of cosmic rays (CRs) accelerated within the Milky Way. Westerlund 1, the most massive known young stellar cluster in our Galaxy is a prime candidate for studying this hypothesis. While the very-high-energy $纬$-ray source HESS J1646-458 has been detected in the vicinity of Westerlund 1 in the past, its association could not be firmly identified. We aim to identify the physical processes responsible for the $纬$-ray emission around Westerlund 1 and thus to better understand the role of massive stellar clusters in the acceleration of Galactic CRs. Using 164 hours of data recorded with the High Energy Stereoscopic System (H.E.S.S.), we carried out a deep spectromorphological study of the $纬$-ray emission of HESS J1646-458. We furthermore employed H I and CO observations of the region to infer the presence of gas that could serve as target material for interactions of accelerated CRs. We detected large-scale ($\sim 2^\circ$ diameter) $纬$-ray emission with a complex morphology, exhibiting a shell-like structure and showing no significant variation with $纬$-ray energy. The combined energy spectrum of the emission extends to several tens of TeV, and is uniform across the entire source region. We did not find a clear correlation of the $纬$-ray emission with gas clouds as identified through H I and CO observations. We conclude that, of the known objects within the region, only Westerlund 1 can explain the bulk of the $纬$-ray emission. Several CR acceleration sites and mechanisms are conceivable, and discussed in detail. (abridged) <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.10921v2-abstract-full').style.display = 'none'; document.getElementById('2207.10921v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 9 figures. Corresponding authors: L. Mohrmann, S. Ohm, R. Rauth, A. Specovius. v2: corrected affiliation of M. Vecchi (still incorrect in journal version)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 666, A124 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.10471">arXiv:2207.10471</a> <span> [<a href="https://arxiv.org/pdf/2207.10471">pdf</a>, <a href="https://arxiv.org/format/2207.10471">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/10.1103/PhysRevLett.129.111101">10.1103/PhysRevLett.129.111101 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Search for dark matter annihilation signals in the H.E.S.S. Inner Galaxy Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Abdalla%2C+H">H. Abdalla</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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=Armand%2C+C">C. Armand</a>, <a href="/search/astro-ph?searchtype=author&query=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Baghmanyan%2C+V">V. Baghmanyan</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernlohr%2C+K">K. Bernlohr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Bottcher%2C+M">M. Bottcher</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Chand%2C+T">T. Chand</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+A">A. Chen</a> , et al. (116 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.10471v1-abstract-short" style="display: inline;"> The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented gamma-ray survey of the Galactic Center (GC) region, ${\it i.e.}$, the Inner Galaxy Survey, at very high energies ($\gtrsim$ 100 GeV) performed with the H.E.S.S. array… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.10471v1-abstract-full').style.display = 'inline'; document.getElementById('2207.10471v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.10471v1-abstract-full" style="display: none;"> The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented gamma-ray survey of the Galactic Center (GC) region, ${\it i.e.}$, the Inner Galaxy Survey, at very high energies ($\gtrsim$ 100 GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant gamma-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section $\langle 蟽v\rangle$. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach $\langle 蟽v\rangle$ values of $\rm 3.7\times10^{-26} cm^3s^{-1}$ for 1.5 TeV DM mass in the $W^+W^-$ annihilation channel, and $\rm 1.2 \times 10^{-26} cm^3s^{-1}$ for 0.7 TeV DM mass in the $蟿^+蟿^-$ annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based $纬$-ray observations thus probe $\langle 蟽v\rangle$ values expected from thermal-relic annihilating TeV DM particles. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.10471v1-abstract-full').style.display = 'none'; document.getElementById('2207.10471v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted in Phys. Rev. Lett., includes Supplemental materials. 5+10 pages, 2+8 figures, 4 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 129, 111101 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.08851">arXiv:2202.08851</a> <span> [<a href="https://arxiv.org/pdf/2202.08851">pdf</a>, <a href="https://arxiv.org/format/2202.08851">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/stac475">10.1093/mnras/stac475 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A statistical study of the optical spectral variability in gamma-ray blazars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Otero-Santos%2C+J">J. Otero-Santos</a>, <a href="/search/astro-ph?searchtype=author&query=Acosta-Pulido%2C+J+A">J. A. Acosta-Pulido</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=Luashvili%2C+A">A. Luashvili</a>, <a href="/search/astro-ph?searchtype=author&query=Segura%2C+N+C">N. Castro Segura</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Mart%C3%ADn%2C+O">O. Gonz谩lez-Mart铆n</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=Carnerero%2C+M+I">M. I. Carnerero</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="2202.08851v1-abstract-short" style="display: inline;"> Blazars optical emission is generally dominated by relativistic jets, although the host galaxy, accretion disk and broad line region (BLR) may also contribute significantly. Disentangling their contributions has been challenging for years due to the dominance of the jet. To quantify the contributions to the spectral variability, we use the statistical technique for dimensionality reduction Non-Neg… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.08851v1-abstract-full').style.display = 'inline'; document.getElementById('2202.08851v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.08851v1-abstract-full" style="display: none;"> Blazars optical emission is generally dominated by relativistic jets, although the host galaxy, accretion disk and broad line region (BLR) may also contribute significantly. Disentangling their contributions has been challenging for years due to the dominance of the jet. To quantify the contributions to the spectral variability, we use the statistical technique for dimensionality reduction Non-Negative Matrix Factorization on a spectroscopic data set of 26 $纬$-ray blazars. This technique allows to model large numbers of spectra in terms of a reduced number of components.We use a priori knowledge to obtain components associated to meaningful physical processes. The sources are classified according to their optical spectrum as host-galaxy dominated BL Lac objects (BL Lacs), BL Lacs, or Flat Spectrum Radio Quasars (FSRQs). Host-galaxy sources show less variability, as expected, and bluer-when-brighter trends, as the other BL Lacs. For FSRQs, more complicated colour-flux behaviours are observed: redder-when-brighter for low states saturating above a certain level and, in some cases, turning to bluer-when-brighter. We are able to reproduce the variability observed during 10 years using only 2 to 4 components, depending on the type. The simplest scenario corresponds to host-galaxy blazars, whose spectra are reconstructed using the stellar population and a power law for the jet. BL Lac spectra are reproduced using from 2 to 4 power laws. Different components can be associated to acceleration/cooling processes taking place in the jet. The reconstruction of FSRQs also incorporates a QSO-like component to account for the BLR, plus a very steep power law, associated to the accretion disk. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.08851v1-abstract-full').style.display = 'none'; document.getElementById('2202.08851v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in 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/2202.08201">arXiv:2202.08201</a> <span> [<a href="https://arxiv.org/pdf/2202.08201">pdf</a>, <a href="https://arxiv.org/format/2202.08201">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/10.1126/science.abn0567">10.1126/science.abn0567 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Time-resolved hadronic particle acceleration in the recurrent Nova RS Ophiuchi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Baghmanyan%2C+V">V. Baghmanyan</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Chand%2C+T">T. Chand</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+A">A. Chen</a> , et al. (150 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="2202.08201v2-abstract-short" style="display: inline;"> Recurrent Novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated by ejected material slamming into the companion star's wind, accelerates particles to very-high-energies. We report very-high-energy (VHE, $\gtrsim100$\,GeV) gamma rays from the recurrent nova RS\,Ophiuchi up to a month afte… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.08201v2-abstract-full').style.display = 'inline'; document.getElementById('2202.08201v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.08201v2-abstract-full" style="display: none;"> Recurrent Novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated by ejected material slamming into the companion star's wind, accelerates particles to very-high-energies. We report very-high-energy (VHE, $\gtrsim100$\,GeV) gamma rays from the recurrent nova RS\,Ophiuchi up to a month after its 2021 outburst, using the High Energy Stereoscopic System. The VHE emission has a similar temporal profile to lower-energy GeV emission, indicating a common origin, with a two-day delay in peak flux. These observations constrain models of time-dependent particle energization, favouring a hadronic emission scenario over the leptonic alternative. This confirms that shocks in dense winds provide favourable environments for efficient cosmic-ray acceleration to very-high-energies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.08201v2-abstract-full').style.display = 'none'; document.getElementById('2202.08201v2-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 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 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">Submitted 1st Nov. 2021, first release 10th March 2022 (accepted version)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.05839">arXiv:2201.05839</a> <span> [<a href="https://arxiv.org/pdf/2201.05839">pdf</a>, <a href="https://arxiv.org/ps/2201.05839">ps</a>, <a href="https://arxiv.org/format/2201.05839">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/10.1051/0004-6361/202243096">10.1051/0004-6361/202243096 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evidence for gamma-ray emission from the remnant of Kepler's supernova based on deep H.E.S.S. observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernloehr%2C+K">K. Bernloehr</a>, <a href="/search/astro-ph?searchtype=author&query=Boettcher%2C+M">M. Boettcher</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>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a>, <a href="/search/astro-ph?searchtype=author&query=Casanova%2C+S">S. Casanova</a>, <a href="/search/astro-ph?searchtype=author&query=Cerruti%2C+M">M. Cerruti</a>, <a href="/search/astro-ph?searchtype=author&query=Chand%2C+T">T. Chand</a> , et al. (136 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="2201.05839v3-abstract-short" style="display: inline;"> Observations with imaging atmospheric Cherenkov telescopes (IACTs) have enhanced our knowledge of nearby supernova (SN) remnants with ages younger than 500 years by establishing Cassiopeia A and the remnant of Tycho's SN as very-high-energy (VHE) gamma-ray sources. The remnant of Kepler's SN, which is the product of the most recent naked-eye supernova in our Galaxy, is comparable in age to the oth… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.05839v3-abstract-full').style.display = 'inline'; document.getElementById('2201.05839v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.05839v3-abstract-full" style="display: none;"> Observations with imaging atmospheric Cherenkov telescopes (IACTs) have enhanced our knowledge of nearby supernova (SN) remnants with ages younger than 500 years by establishing Cassiopeia A and the remnant of Tycho's SN as very-high-energy (VHE) gamma-ray sources. The remnant of Kepler's SN, which is the product of the most recent naked-eye supernova in our Galaxy, is comparable in age to the other two, but is significantly more distant. If the gamma-ray luminosities of the remnants of Tycho's and Kepler's SNe are similar, then the latter is expected to be one of the faintest gamma-ray sources within reach of the current generation IACT arrays. Here we report evidence at a statistical level of 4.6 sigma for a VHE signal from the remnant of Kepler's SN based on deep observations by the High Energy Stereoscopic System (H.E.S.S.) with an exposure of 152 hours. The measured integral flux above an energy of 226 GeV is ~0.3% of the flux of the Crab Nebula. The spectral energy distribution (SED) reveals a gamma-ray emitting component connecting the VHE emission observed with H.E.S.S. to the emission observed at GeV energies with Fermi-LAT. The overall SED is similar to that of the remnant of Tycho's SN, possibly indicating the same non-thermal emission processes acting in both these young remnants of thermonuclear SNe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.05839v3-abstract-full').style.display = 'none'; document.getElementById('2201.05839v3-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 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in Astronomy and Astrophysics. A typo in the normalization constant in Sect. 4 was corrected</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 662, A65 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.00069">arXiv:2201.00069</a> <span> [<a href="https://arxiv.org/pdf/2201.00069">pdf</a>, <a href="https://arxiv.org/format/2201.00069">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </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/stac1601">10.1093/mnras/stac1601 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A MeerKAT, e-MERLIN, H.E.S.S. and Swift search for persistent and transient emission associated with three localised FRBs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chibueze%2C+J+O">James O. Chibueze</a>, <a href="/search/astro-ph?searchtype=author&query=Caleb%2C+M">M. Caleb</a>, <a href="/search/astro-ph?searchtype=author&query=Spitler%2C+L">L. Spitler</a>, <a href="/search/astro-ph?searchtype=author&query=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Schussler%2C+F">F. Schussler</a>, <a href="/search/astro-ph?searchtype=author&query=Stappers%2C+B+W">B. W. Stappers</a>, <a href="/search/astro-ph?searchtype=author&query=Venter%2C+C">C. Venter</a>, <a href="/search/astro-ph?searchtype=author&query=Heywood%2C+I">I. Heywood</a>, <a href="/search/astro-ph?searchtype=author&query=Richards%2C+A+M+S">A. M. S. Richards</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+D+R+A">D. R. A. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Kramer%2C+M">M. Kramer</a>, <a href="/search/astro-ph?searchtype=author&query=Beswick%2C+R">R. Beswick</a>, <a href="/search/astro-ph?searchtype=author&query=Bezuidenhout%2C+M+C">M. C. Bezuidenhout</a>, <a href="/search/astro-ph?searchtype=author&query=Breton%2C+R+P">R. P. Breton</a>, <a href="/search/astro-ph?searchtype=author&query=Driessen%2C+L+N">L. N. Driessen</a>, <a href="/search/astro-ph?searchtype=author&query=Jankowski%2C+F">F. Jankowski</a>, <a href="/search/astro-ph?searchtype=author&query=Keane%2C+E+F">E. F. Keane</a>, <a href="/search/astro-ph?searchtype=author&query=Malenta%2C+M">M. Malenta</a>, <a href="/search/astro-ph?searchtype=author&query=Mickaliger%2C+M">M. Mickaliger</a>, <a href="/search/astro-ph?searchtype=author&query=Morello%2C+V">V. Morello</a>, <a href="/search/astro-ph?searchtype=author&query=Qiu%2C+H">H. Qiu</a>, <a href="/search/astro-ph?searchtype=author&query=Rajwade%2C+K">K. Rajwade</a>, <a href="/search/astro-ph?searchtype=author&query=Sanidas%2C+S">S. Sanidas</a>, <a href="/search/astro-ph?searchtype=author&query=Surnis%2C+M">M. Surnis</a>, <a href="/search/astro-ph?searchtype=author&query=Scragg%2C+T+W">T. W. Scragg</a> , et al. (134 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="2201.00069v1-abstract-short" style="display: inline;"> We report on a search for persistent radio emission from the one-off Fast Radio Burst (FRB) 20190714A, as well as from two repeating FRBs, 20190711A and 20171019A, using the MeerKAT radio telescope. For FRB 20171019A we also conducted simultaneous observations with the High Energy Stereoscopic System (H.E.S.S.) in very high energy gamma rays and searched for signals in the ultraviolet, optical, an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.00069v1-abstract-full').style.display = 'inline'; document.getElementById('2201.00069v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.00069v1-abstract-full" style="display: none;"> We report on a search for persistent radio emission from the one-off Fast Radio Burst (FRB) 20190714A, as well as from two repeating FRBs, 20190711A and 20171019A, using the MeerKAT radio telescope. For FRB 20171019A we also conducted simultaneous observations with the High Energy Stereoscopic System (H.E.S.S.) in very high energy gamma rays and searched for signals in the ultraviolet, optical, and X-ray bands. For this FRB, we obtain a UV flux upper limit of 1.39x10^-16 erg/cm^-2/s/Amstrong, X-ray limit of ~ 6.6x10^-14 erg/cm^-2/s and a limit on the very-high-energy gamma-ray flux (Phi) (E > 120 GeV) < 1.7 x 10^-12 erg/cm^-2/s. We obtain a radio upper limit of ~15 microJy/beam for persistent emission at the locations of both FRBs 20190711A and 20171019A, but detect diffuse radio emission with a peak brightness of ~53 microJy/beam associated with FRB 20190714A at z = 0.2365. This represents the first detection of the radio continuum emission potentially associated with the host (galaxy) of FRB 20190714A, and is only the third known FRB to have such an association. Given the possible association of a faint persistent source, FRB 20190714A may potentially be a repeating FRB whose age lies between that of FRB 20121102A and FRB 20180916A. A parallel search for repeat bursts from these FRBs revealed no new detections down to a fluence of 0.08 Jy ms for a 1 ms duration burst. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.00069v1-abstract-full').style.display = 'none'; document.getElementById('2201.00069v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 9 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.08307">arXiv:2112.08307</a> <span> [<a href="https://arxiv.org/pdf/2112.08307">pdf</a>, <a href="https://arxiv.org/format/2112.08307">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/ac2e04">10.3847/1538-4357/ac2e04 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> H.E.S.S. follow-up observations of Binary Black Hole Coalescence events during the second and third Gravitational Waves observing runs of Advanced LIGO and Advanced Virgo </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=collaboration%2C+H+E+S+S">H. E. S. S. collaboration</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=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Baghmanyan%2C+V">V. Baghmanyan</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Batzofin%2C+R">R. Batzofin</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a>, <a href="/search/astro-ph?searchtype=author&query=Bulik%2C+T">T. Bulik</a>, <a href="/search/astro-ph?searchtype=author&query=Bylund%2C+T">T. Bylund</a>, <a href="/search/astro-ph?searchtype=author&query=Cangemi%2C+F">F. Cangemi</a>, <a href="/search/astro-ph?searchtype=author&query=Caroff%2C+S">S. Caroff</a> , et al. (129 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="2112.08307v1-abstract-short" style="display: inline;"> We report on the observations of four well-localized binary black hole (BBH) mergers by the High Energy Stereoscopic System (H.E.S.S.) during the second and third observing runs of Advanced LIGO and Advanced Virgo, O2 and O3. H.E.S.S. can observe $\mathrm{20\,deg^2}$ of the sky at a time and follows up gravitational-wave (GW) events by ``tiling'' localization regions to maximize the covered locali… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.08307v1-abstract-full').style.display = 'inline'; document.getElementById('2112.08307v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.08307v1-abstract-full" style="display: none;"> We report on the observations of four well-localized binary black hole (BBH) mergers by the High Energy Stereoscopic System (H.E.S.S.) during the second and third observing runs of Advanced LIGO and Advanced Virgo, O2 and O3. H.E.S.S. can observe $\mathrm{20\,deg^2}$ of the sky at a time and follows up gravitational-wave (GW) events by ``tiling'' localization regions to maximize the covered localization probability. During O2 and O3, H.E.S.S. observed large portions of the localization regions, between 35\% and 75\%, for four BBH mergers (GW170814, GW190512\_180714, GW190728\_064510, and S200224ca). For these four GW events, we find no significant signal from a pointlike source in any of the observations, and set upper limits on the very high energy ($>$100 GeV) $纬$-ray emission. The 1-10 TeV isotropic luminosity of these GW events is below $10^{45}$ erg s$^{-1}$ at the times of the H.E.S.S. observations, around the level of the low-luminosity GRB 190829A. Assuming no changes are made to how follow-up observations are conducted, H.E.S.S. can expect to observe over 60 GW events per year in the fourth GW observing run, O4, of which eight would be observable with minimal latency. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.08307v1-abstract-full').style.display = 'none'; document.getElementById('2112.08307v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJ, 923, 109 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.00636">arXiv:2110.00636</a> <span> [<a href="https://arxiv.org/pdf/2110.00636">pdf</a>, <a href="https://arxiv.org/format/2110.00636">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/ac0fe1">10.3847/1538-4357/ac0fe1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Searching for TeV gamma-ray emission from SGR\,1935+2154 during its 2020 X-ray and radio bursting phase </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</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=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</a>, <a href="/search/astro-ph?searchtype=author&query=Ang%7Funer%2C+E+O">E. O. Anguner</a>, <a href="/search/astro-ph?searchtype=author&query=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Armand%2C+C">C. Armand</a>, <a href="/search/astro-ph?searchtype=author&query=Armstrong%2C+T">T. Armstrong</a>, <a href="/search/astro-ph?searchtype=author&query=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Baghmanyan%2C+V">V. Baghmanyan</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Barnacka%2C+A">A. Barnacka</a>, <a href="/search/astro-ph?searchtype=author&query=Barnard%2C+M">M. Barnard</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%7Fohr%2C+K">K. Bernlohr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=B%7Fottcher%2C+M">M. Bottcher</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>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a> , et al. (230 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="2110.00636v1-abstract-short" style="display: inline;"> Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRB) -- enigmatic powerful radio pulses with durations of several milliseconds and high brightness temperatures. The first observational evidence for this scenario was obtained in 2020 April when a FRB was detected from the direction of the Galactic magnetar and soft gamma-ray repeater SGR\,1935+2154. The FRB was preced… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.00636v1-abstract-full').style.display = 'inline'; document.getElementById('2110.00636v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.00636v1-abstract-full" style="display: none;"> Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRB) -- enigmatic powerful radio pulses with durations of several milliseconds and high brightness temperatures. The first observational evidence for this scenario was obtained in 2020 April when a FRB was detected from the direction of the Galactic magnetar and soft gamma-ray repeater SGR\,1935+2154. The FRB was preceded by two gamma-ray outburst alerts by the BAT instrument aboard the Swift satellite, which triggered follow-up observations by the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. has observed SGR\,1935+2154 for 2 hr on 2020 April 28. The observations are coincident with X-ray bursts from the magnetar detected by INTEGRAL and Fermi-GBM, thus providing the first very high energy (VHE) gamma-ray observations of a magnetar in a flaring state. High-quality data acquired during these follow-up observations allow us to perform a search for short-time transients. No significant signal at energies $E>0.6$~TeV is found and upper limits on the persistent and transient emission are derived. We here present the analysis of these observations and discuss the obtained results and prospects of the H.E.S.S. follow-up program for soft gamma-ray repeaters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.00636v1-abstract-full').style.display = 'none'; document.getElementById('2110.00636v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 October, 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">Received 2021 June 13; accepted 2021 June 28; published 2021 September 29</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.11894">arXiv:2109.11894</a> <span> [<a href="https://arxiv.org/pdf/2109.11894">pdf</a>, <a href="https://arxiv.org/format/2109.11894">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/ac29b7">10.3847/1538-4357/ac29b7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of the gamma-ray binary HESS J0632+057 with the H.E.S.S., MAGIC, and VERITAS telescopes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Adams%2C+C+B">C. B. Adams</a>, <a href="/search/astro-ph?searchtype=author&query=Benbow%2C+W">W. Benbow</a>, <a href="/search/astro-ph?searchtype=author&query=Brill%2C+A">A. Brill</a>, <a href="/search/astro-ph?searchtype=author&query=Buckley%2C+J+H">J. H. Buckley</a>, <a href="/search/astro-ph?searchtype=author&query=Capasso%2C+M">M. Capasso</a>, <a href="/search/astro-ph?searchtype=author&query=Chromey%2C+A+J">A. J. Chromey</a>, <a href="/search/astro-ph?searchtype=author&query=Errando%2C+M">M. Errando</a>, <a href="/search/astro-ph?searchtype=author&query=Falcone%2C+A">A. Falcone</a>, <a href="/search/astro-ph?searchtype=author&query=Farrell%2C+K+A">K. A. Farrell</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Q">Q. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Finley%2C+J+P">J P. Finley</a>, <a href="/search/astro-ph?searchtype=author&query=Foote%2C+G">G. Foote</a>, <a href="/search/astro-ph?searchtype=author&query=Fortson%2C+L">L. Fortson</a>, <a href="/search/astro-ph?searchtype=author&query=Furniss%2C+A">A. Furniss</a>, <a href="/search/astro-ph?searchtype=author&query=Gent%2C+A">A. Gent</a>, <a href="/search/astro-ph?searchtype=author&query=Gillanders%2C+G+H">G. H. Gillanders</a>, <a href="/search/astro-ph?searchtype=author&query=Giuri%2C+C">C. Giuri</a>, <a href="/search/astro-ph?searchtype=author&query=Gueta%2C+O">O. Gueta</a>, <a href="/search/astro-ph?searchtype=author&query=Hanna%2C+D">D. Hanna</a>, <a href="/search/astro-ph?searchtype=author&query=Hassan%2C+T">T. Hassan</a>, <a href="/search/astro-ph?searchtype=author&query=Hervet%2C+O">O. Hervet</a>, <a href="/search/astro-ph?searchtype=author&query=Holder%2C+J">J. Holder</a>, <a href="/search/astro-ph?searchtype=author&query=Hona%2C+B">B. Hona</a>, <a href="/search/astro-ph?searchtype=author&query=Humensky%2C+T+B">T. B. Humensky</a>, <a href="/search/astro-ph?searchtype=author&query=Jin%2C+W">W. Jin</a> , et al. (387 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="2109.11894v1-abstract-short" style="display: inline;"> The results of gamma-ray observations of the binary system HESS J0632+057 collected during 450 hours over 15 years, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these obs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.11894v1-abstract-full').style.display = 'inline'; document.getElementById('2109.11894v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.11894v1-abstract-full" style="display: none;"> The results of gamma-ray observations of the binary system HESS J0632+057 collected during 450 hours over 15 years, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H伪 emission line. A significant detection of the modulation of the VHE gamma-ray fluxes with a period of 316.7+-4.4 days is reported, consistent with the period of 317.3+-0.7 days obtained with a refined analysis of X-ray data. The analysis of data of four orbital cycles with dense observational coverage reveals short timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over the time scale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but can not find any correlation of optical H伪 parameters with X-ray or gamma-ray energy fluxes in simultaneous observations. The key finding is that the emission of HESS J0632+057 in the X-ray and gamma-ray energy bands is highly variable on different time scales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.11894v1-abstract-full').style.display = 'none'; document.getElementById('2109.11894v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication by 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/2106.00551">arXiv:2106.00551</a> <span> [<a href="https://arxiv.org/pdf/2106.00551">pdf</a>, <a href="https://arxiv.org/format/2106.00551">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/abff59">10.3847/1538-4357/abff59 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Search for dark matter annihilation signals from unidentified Fermi-LAT objects with H.E.S.S </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+H+E+S+S">H. E. S. S. Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Abdallah%2C+H">H. Abdallah</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Benkhali%2C+F+A">F. Ait Benkhali</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=Arcaro%2C+C">C. Arcaro</a>, <a href="/search/astro-ph?searchtype=author&query=Armand%2C+C">C. Armand</a>, <a href="/search/astro-ph?searchtype=author&query=Armstrong%2C+T">T. Armstrong</a>, <a href="/search/astro-ph?searchtype=author&query=Ashkar%2C+H">H. Ashkar</a>, <a href="/search/astro-ph?searchtype=author&query=Backes%2C+M">M. Backes</a>, <a href="/search/astro-ph?searchtype=author&query=Baghmanyan%2C+V">V. Baghmanyan</a>, <a href="/search/astro-ph?searchtype=author&query=Martins%2C+V+B">V. Barbosa Martins</a>, <a href="/search/astro-ph?searchtype=author&query=Barnacka%2C+A">A. Barnacka</a>, <a href="/search/astro-ph?searchtype=author&query=Barnard%2C+M">M. Barnard</a>, <a href="/search/astro-ph?searchtype=author&query=Becherini%2C+Y">Y. Becherini</a>, <a href="/search/astro-ph?searchtype=author&query=Berge%2C+D">D. Berge</a>, <a href="/search/astro-ph?searchtype=author&query=Bernl%C3%B6hr%2C+K">K. Bernl枚hr</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+B">B. Bi</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=Boisson%2C+C">C. Boisson</a>, <a href="/search/astro-ph?searchtype=author&query=Bolmont%2C+J">J. Bolmont</a>, <a href="/search/astro-ph?searchtype=author&query=de+Lavergne%2C+M+d+B">M. de Bony de Lavergne</a>, <a href="/search/astro-ph?searchtype=author&query=Breuhaus%2C+M">M. Breuhaus</a>, <a href="/search/astro-ph?searchtype=author&query=Brose%2C+R">R. Brose</a>, <a href="/search/astro-ph?searchtype=author&query=Brun%2C+F">F. Brun</a> , et al. (205 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="2106.00551v2-abstract-short" style="display: inline;"> Cosmological $N$-body simulations show that Milky Way-sized galaxies harbor a population of unmerged dark matter subhalos. These subhalos could shine in gamma-rays and be eventually detected in gamma-ray surveys as unidentified sources. We performed a thorough selection among unidentified Fermi-LAT Objects (UFOs) to identify them as possible TeV-scale dark matter subhalo candidates. We search for… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.00551v2-abstract-full').style.display = 'inline'; document.getElementById('2106.00551v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.00551v2-abstract-full" style="display: none;"> Cosmological $N$-body simulations show that Milky Way-sized galaxies harbor a population of unmerged dark matter subhalos. These subhalos could shine in gamma-rays and be eventually detected in gamma-ray surveys as unidentified sources. We performed a thorough selection among unidentified Fermi-LAT Objects (UFOs) to identify them as possible TeV-scale dark matter subhalo candidates. We search for very-high-energy (E $\gtrsim$ 100 GeV) gamma-ray emissions using H.E.S.S. observations towards four selected UFOs. Since no significant very-high-energy gamma-ray emission is detected in any dataset of the four observed UFOs nor in the combined UFO dataset, strong constraints are derived on the product of the velocity-weighted annihilation cross section $\langle 蟽v \rangle$ by the $J$-factor for the dark matter models. The 95% C.L. observed upper limits derived from combined H.E.S.S. observations reach $\langle 蟽v \rangle J$ values of 3.7$\times$10$^{-5}$ and 8.1$\times$10$^{-6}$ GeV$^2$cm$^{-2}$s$^{-1}$ in the $W^+W^-$ and $蟿^+蟿^-$ channels, respectively, for a 1 TeV dark matter mass. Focusing on thermal WIMPs, the H.E.S.S. constraints restrict the $J$-factors to lie in the range 6.1$\times$10$^{19}$ - 2.0$\times$10$^{21}$ GeV$^2$cm$^{-5}$, and the masses to lie between 0.2 and 6 TeV in the $W^+W^-$ channel. For the $蟿^+蟿^-$ channel, the $J$-factors lie in the range 7.0$\times$10$^{19}$ - 7.1$\times$10$^{20}$ GeV$^2$cm$^{-5}$ and the masses lie between 0.2 and 0.5 TeV. Assuming model-dependent predictions from cosmological N-body simulations on the $J$-factor distribution for Milky Way-sized galaxies, the dark matter models with masses greater than 0.3 TeV for the UFO emissions can be ruled out at high confidence level. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.00551v2-abstract-full').style.display = 'none'; document.getElementById('2106.00551v2-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 1 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">11 pages, 7 figures, matches accepted version in The Astrophysical Journal</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J., 918, 17 (2021) </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 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