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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Zhang%2C+S&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Zhang%2C+S&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+S&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+S&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+S&start=150" class="pagination-link " aria-label="Page 4" aria-current="page">4 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+S&start=200" class="pagination-link " aria-label="Page 5" aria-current="page">5 </a> </li> <li><span class="pagination-ellipsis">…</span></li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.09580">arXiv:2501.09580</a> <span> [<a href="https://arxiv.org/pdf/2501.09580">pdf</a>, <a href="https://arxiv.org/format/2501.09580">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> <p class="title is-5 mathjax"> An Intermediate-mass Black Hole Lurking in A Galactic Halo Caught Alive during Outburst </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jin%2C+C+-">C. -C. Jin</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+D+-">D. -Y. Li</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+N">N. Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L+-">L. -X. Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+H+-">H. -Q. Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+J+-">J. -Z. Zhu</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+C+-">C. -W. Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Rau%2C+A">A. Rau</a>, <a href="/search/astro-ph?searchtype=author&query=Baldini%2C+P">P. Baldini</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+T+-">T. -G. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+H+-">H. -Y. Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Yuan%2C+W">W. Yuan</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+C">C. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Shu%2C+X+-">X. -W. Shu</a>, <a href="/search/astro-ph?searchtype=author&query=Shen%2C+R+-">R. -F. Shen</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Y+-">Y. -L. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wen%2C+S+-">S. -X. Wen</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+Q+-">Q. -Y. Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Y+-">Y. -B. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Thomsen%2C+L+L">L. L. Thomsen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Z+-">Z. -J. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+W+-">W. -J. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Coleiro%2C+A">A. Coleiro</a>, <a href="/search/astro-ph?searchtype=author&query=Eyles-Ferris%2C+R">R. Eyles-Ferris</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+X">X. Fang</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="2501.09580v1-abstract-short" style="display: inline;"> Stellar-mass and supermassive black holes abound in the Universe, whereas intermediate-mass black holes (IMBHs) of ~10^2-10^5 solar masses in between are largely missing observationally, with few cases found only. Here we report the real-time discovery of a long-duration X-ray transient, EP240222a, accompanied by an optical flare with prominent H and He emission lines revealed by prompt follow-up… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.09580v1-abstract-full').style.display = 'inline'; document.getElementById('2501.09580v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.09580v1-abstract-full" style="display: none;"> Stellar-mass and supermassive black holes abound in the Universe, whereas intermediate-mass black holes (IMBHs) of ~10^2-10^5 solar masses in between are largely missing observationally, with few cases found only. Here we report the real-time discovery of a long-duration X-ray transient, EP240222a, accompanied by an optical flare with prominent H and He emission lines revealed by prompt follow-up observations. Its observed properties evidence an IMBH located unambiguously in the halo of a nearby galaxy and flaring by tidally disrupting a star -- the only confirmed off-nucleus IMBH-tidal disruption event so far. This work demonstrates the potential of sensitive time-domain X-ray surveys, complemented by timely multi-wavelength follow-ups, in probing IMBHs, their environments, demographics, origins and connections to stellar-mass and supermassive black holes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.09580v1-abstract-full').style.display = 'none'; document.getElementById('2501.09580v1-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">64 pages, 15 figures, submitted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.09276">arXiv:2501.09276</a> <span> [<a href="https://arxiv.org/pdf/2501.09276">pdf</a>, <a href="https://arxiv.org/format/2501.09276">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"> Search for neutrino doublets and triplets using 11.4 years of IceCube data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Abbasi%2C+R">R. Abbasi</a>, <a href="/search/astro-ph?searchtype=author&query=Ackermann%2C+M">M. Ackermann</a>, <a href="/search/astro-ph?searchtype=author&query=Adams%2C+J">J. Adams</a>, <a href="/search/astro-ph?searchtype=author&query=Agarwalla%2C+S+K">S. K. Agarwalla</a>, <a href="/search/astro-ph?searchtype=author&query=Aguilar%2C+J+A">J. A. Aguilar</a>, <a href="/search/astro-ph?searchtype=author&query=Ahlers%2C+M">M. Ahlers</a>, <a href="/search/astro-ph?searchtype=author&query=Alameddine%2C+J+M">J. M. Alameddine</a>, <a href="/search/astro-ph?searchtype=author&query=Amin%2C+N+M">N. M. Amin</a>, <a href="/search/astro-ph?searchtype=author&query=Andeen%2C+K">K. Andeen</a>, <a href="/search/astro-ph?searchtype=author&query=Arg%C3%BCelles%2C+C">C. Arg眉elles</a>, <a href="/search/astro-ph?searchtype=author&query=Ashida%2C+Y">Y. Ashida</a>, <a href="/search/astro-ph?searchtype=author&query=Athanasiadou%2C+S">S. Athanasiadou</a>, <a href="/search/astro-ph?searchtype=author&query=Axani%2C+S+N">S. N. Axani</a>, <a href="/search/astro-ph?searchtype=author&query=Babu%2C+R">R. Babu</a>, <a href="/search/astro-ph?searchtype=author&query=Bai%2C+X">X. Bai</a>, <a href="/search/astro-ph?searchtype=author&query=V.%2C+A+B">A. Balagopal V.</a>, <a href="/search/astro-ph?searchtype=author&query=Baricevic%2C+M">M. Baricevic</a>, <a href="/search/astro-ph?searchtype=author&query=Barwick%2C+S+W">S. W. Barwick</a>, <a href="/search/astro-ph?searchtype=author&query=Bash%2C+S">S. Bash</a>, <a href="/search/astro-ph?searchtype=author&query=Basu%2C+V">V. Basu</a>, <a href="/search/astro-ph?searchtype=author&query=Bay%2C+R">R. Bay</a>, <a href="/search/astro-ph?searchtype=author&query=Beatty%2C+J+J">J. J. Beatty</a>, <a href="/search/astro-ph?searchtype=author&query=Tjus%2C+J+B">J. Becker Tjus</a>, <a href="/search/astro-ph?searchtype=author&query=Beise%2C+J">J. Beise</a>, <a href="/search/astro-ph?searchtype=author&query=Bellenghi%2C+C">C. Bellenghi</a> , et al. (402 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="2501.09276v1-abstract-short" style="display: inline;"> We report a search for high-energy astrophysical neutrino multiplets, detections of multiple neutrino clusters in the same direction within 30 days, based on an analysis of 11.4 years of IceCube data. A new search method optimized for transient neutrino emission with a monthly time scale is employed, providing a higher sensitivity to neutrino fluxes. This result is sensitive to neutrino transient… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.09276v1-abstract-full').style.display = 'inline'; document.getElementById('2501.09276v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.09276v1-abstract-full" style="display: none;"> We report a search for high-energy astrophysical neutrino multiplets, detections of multiple neutrino clusters in the same direction within 30 days, based on an analysis of 11.4 years of IceCube data. A new search method optimized for transient neutrino emission with a monthly time scale is employed, providing a higher sensitivity to neutrino fluxes. This result is sensitive to neutrino transient emission, reaching per-flavor flux of approximately $10^{-10}\ {\rm erg}\ {\rm cm}^{-2}\ {\rm sec}^{-1}$ from the Northern sky in the energy range $E\gtrsim 50$~TeV. The number of doublets and triplets identified in this search is compatible with the atmospheric background hypothesis, which leads us to set limits on the nature of neutrino transient sources with emission timescales of one month. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.09276v1-abstract-full').style.display = 'none'; document.getElementById('2501.09276v1-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.09248">arXiv:2501.09248</a> <span> [<a href="https://arxiv.org/pdf/2501.09248">pdf</a>, <a href="https://arxiv.org/format/2501.09248">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A universal break in energy functions of three hyperactive repeating fast radio bursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wu%2C+Q">Q. Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+F+Y">F. Y. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+Z+Y">Z. Y. Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+P">P. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+H">H. Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y+K">Y. K. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+D+J">D. J. Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Niu%2C+J+R">J. R. Niu</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+W+Y">W. Y. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Yi%2C+S+X">S. X. Yi</a>, <a href="/search/astro-ph?searchtype=author&query=Hua%2C+Z+Q">Z. Q. Hua</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S+B">S. B. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Han%2C+J+L">J. L. Han</a>, <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+W+W">W. W. Zhu</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+K+J">K. J. Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+D">D. Li</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+X+F">X. F. Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+Z+G">Z. G. Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+B">B. Zhang</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="2501.09248v1-abstract-short" style="display: inline;"> Fast radio bursts (FRBs) are millisecond-duration pulses occurring at cosmological distances with a mysterious origin. Observations show that at least some FRBs are produced by magnetars. All magnetar-powered FRB models require some triggering mechanisms, among which the most popular is the crust cracking of a neutron star, which is called starquake. However, so far there has been no decisive evid… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.09248v1-abstract-full').style.display = 'inline'; document.getElementById('2501.09248v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.09248v1-abstract-full" style="display: none;"> Fast radio bursts (FRBs) are millisecond-duration pulses occurring at cosmological distances with a mysterious origin. Observations show that at least some FRBs are produced by magnetars. All magnetar-powered FRB models require some triggering mechanisms, among which the most popular is the crust cracking of a neutron star, which is called starquake. However, so far there has been no decisive evidence for this speculation. Here we report the energy functions of the three most active repeating FRBs, which show a universal break around $10^{38}$ erg. Such a break is similar to that of the frequency-magnitude relationship of earthquakes. The break and change of the power-law indices below and above it can be well understood within the framework of FRBs triggered by starquakes in the magnetar models. The seed of weak FRBs can grow both on the magnetar surface and in the deeper crust. In contrast, the triggering of strong FRBs is confined by the crustal thickness and the seed of strong FRBs can only grow on the surface. This difference in dimensionality causes a break in the scaling properties from weak to strong FRBs, occurring at a point where the penetration depth of starquakes equals the crustal thickness. Our result, together with the earthquake-like temporal properties of these FRBs, strongly supports that FRBs are triggered by starquakes, providing a new opportunity to study the physical properties of the neutron star crust. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.09248v1-abstract-full').style.display = 'none'; document.getElementById('2501.09248v1-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 6 figures. Accepted for publication in The Astrophysical Journal Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.08685">arXiv:2501.08685</a> <span> [<a href="https://arxiv.org/pdf/2501.08685">pdf</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/10.1051/0004-6361/202450898">10.1051/0004-6361/202450898 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The putative center in NGC 1052 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Baczko%2C+A">Anne-Kathrin Baczko</a>, <a href="/search/astro-ph?searchtype=author&query=Kadler%2C+M">Matthias Kadler</a>, <a href="/search/astro-ph?searchtype=author&query=Ros%2C+E">Eduardo Ros</a>, <a href="/search/astro-ph?searchtype=author&query=Fromm%2C+C+M">Christian M. Fromm</a>, <a href="/search/astro-ph?searchtype=author&query=Wielgus%2C+M">Maciek Wielgus</a>, <a href="/search/astro-ph?searchtype=author&query=Perucho%2C+M">Manel Perucho</a>, <a href="/search/astro-ph?searchtype=author&query=Krichbaum%2C+T+P">Thomas P. Krichbaum</a>, <a href="/search/astro-ph?searchtype=author&query=Balokovi%C4%87%2C+M">Mislav Balokovi膰</a>, <a href="/search/astro-ph?searchtype=author&query=Blackburn%2C+L">Lindy Blackburn</a>, <a href="/search/astro-ph?searchtype=author&query=Chan%2C+C">Chi-kwan Chan</a>, <a href="/search/astro-ph?searchtype=author&query=Issaoun%2C+S">Sara Issaoun</a>, <a href="/search/astro-ph?searchtype=author&query=Janssen%2C+M">Michael Janssen</a>, <a href="/search/astro-ph?searchtype=author&query=Ricci%2C+L">Luca Ricci</a>, <a href="/search/astro-ph?searchtype=author&query=Akiyama%2C+K">Kazunori Akiyama</a>, <a href="/search/astro-ph?searchtype=author&query=Albentosa-Ru%C3%ADz%2C+E">Ezequiel Albentosa-Ru铆z</a>, <a href="/search/astro-ph?searchtype=author&query=Alberdi%2C+A">Antxon Alberdi</a>, <a href="/search/astro-ph?searchtype=author&query=Alef%2C+W">Walter Alef</a>, <a href="/search/astro-ph?searchtype=author&query=Algaba%2C+J+C">Juan Carlos Algaba</a>, <a href="/search/astro-ph?searchtype=author&query=Anantua%2C+R">Richard Anantua</a>, <a href="/search/astro-ph?searchtype=author&query=Asada%2C+K">Keiichi Asada</a>, <a href="/search/astro-ph?searchtype=author&query=Azulay%2C+R">Rebecca Azulay</a>, <a href="/search/astro-ph?searchtype=author&query=Bach%2C+U">Uwe Bach</a>, <a href="/search/astro-ph?searchtype=author&query=Ball%2C+D">David Ball</a>, <a href="/search/astro-ph?searchtype=author&query=Bandyopadhyay%2C+B">Bidisha Bandyopadhyay</a>, <a href="/search/astro-ph?searchtype=author&query=Barrett%2C+J">John Barrett</a> , et al. (262 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="2501.08685v1-abstract-short" style="display: inline;"> Many active galaxies harbor powerful relativistic jets, however, the detailed mechanisms of their formation and acceleration remain poorly understood. To investigate the area of jet acceleration and collimation with the highest available angular resolution, we study the innermost region of the bipolar jet in the nearby low-ionization nuclear emission-line region (LINER) galaxy NGC 1052. We combine… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.08685v1-abstract-full').style.display = 'inline'; document.getElementById('2501.08685v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.08685v1-abstract-full" style="display: none;"> Many active galaxies harbor powerful relativistic jets, however, the detailed mechanisms of their formation and acceleration remain poorly understood. To investigate the area of jet acceleration and collimation with the highest available angular resolution, we study the innermost region of the bipolar jet in the nearby low-ionization nuclear emission-line region (LINER) galaxy NGC 1052. We combined observations of NGC 1052 taken with VLBA, GMVA, and EHT over one week in the spring of 2017. For the first time, NGC 1052 was detected with the EHT, providing a size of the central region in-between both jet bases of 250 RS (Schwarzschild radii) perpendicular to the jet axes. This size estimate supports previous studies of the jets expansion profile which suggest two breaks of the profile at around 300 RS and 10000 RS distances to the core. Furthermore, we estimated the magnetic field to be 1.25 Gauss at a distance of 22 渭as from the central engine by fitting a synchrotron-self absorption spectrum to the innermost emission feature, which shows a spectral turn-over at about 130 GHz. Assuming a purely poloidal magnetic field, this implies an upper limit on the magnetic field strength at the event horizon of 26000 Gauss, which is consistent with previous measurements. The complex, low-brightness, double-sided jet structure in NGC 1052 makes it a challenge to detect the source at millimeter (mm) wavelengths. However, our first EHT observations have demonstrated that detection is possible up to at least 230 GHz. This study offers a glimpse through the dense surrounding torus and into the innermost central region, where the jets are formed. This has enabled us to finally resolve this region and provide improved constraints on its expansion and magnetic field strength. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.08685v1-abstract-full').style.display = 'none'; document.getElementById('2501.08685v1-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 10 figures, published in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, 692, A205 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.07415">arXiv:2501.07415</a> <span> [<a href="https://arxiv.org/pdf/2501.07415">pdf</a>, <a href="https://arxiv.org/format/2501.07415">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> <p class="title is-5 mathjax"> First mid-infrared detection and modeling of a flare from Sgr A* </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=von+Fellenberg%2C+S+D">Sebastiano D. von Fellenberg</a>, <a href="/search/astro-ph?searchtype=author&query=Roychowdhury%2C+T">Tamojeet Roychowdhury</a>, <a href="/search/astro-ph?searchtype=author&query=Michail%2C+J+M">Joseph M. Michail</a>, <a href="/search/astro-ph?searchtype=author&query=Sumners%2C+Z">Zach Sumners</a>, <a href="/search/astro-ph?searchtype=author&query=Sanger-Johnson%2C+G">Grace Sanger-Johnson</a>, <a href="/search/astro-ph?searchtype=author&query=Fazio%2C+G+G">Giovanni G. Fazio</a>, <a href="/search/astro-ph?searchtype=author&query=Haggard%2C+D">Daryl Haggard</a>, <a href="/search/astro-ph?searchtype=author&query=Hora%2C+J+L">Joseph L. Hora</a>, <a href="/search/astro-ph?searchtype=author&query=Philippov%2C+A">Alexander Philippov</a>, <a href="/search/astro-ph?searchtype=author&query=Ripperda%2C+B">Bart Ripperda</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+H+A">Howard A. Smith</a>, <a href="/search/astro-ph?searchtype=author&query=Willner%2C+S+P">S. P. Willner</a>, <a href="/search/astro-ph?searchtype=author&query=Witzel%2C+G">Gunther Witzel</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuo Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Becklin%2C+E+E">Eric E. Becklin</a>, <a href="/search/astro-ph?searchtype=author&query=Bower%2C+G+C">Geoffrey C. Bower</a>, <a href="/search/astro-ph?searchtype=author&query=Chandra%2C+S">Sunil Chandra</a>, <a href="/search/astro-ph?searchtype=author&query=Do%2C+T">Tuan Do</a>, <a href="/search/astro-ph?searchtype=author&query=Marin%2C+M+G">Macarena Garcia Marin</a>, <a href="/search/astro-ph?searchtype=author&query=Gurwell%2C+M+A">Mark A. Gurwell</a>, <a href="/search/astro-ph?searchtype=author&query=Ford%2C+N+M">Nicole M. Ford</a>, <a href="/search/astro-ph?searchtype=author&query=Hada%2C+K">Kazuhiro Hada</a>, <a href="/search/astro-ph?searchtype=author&query=Markoff%2C+S">Sera Markoff</a>, <a href="/search/astro-ph?searchtype=author&query=Morris%2C+M+R">Mark R. Morris</a>, <a href="/search/astro-ph?searchtype=author&query=Neilsen%2C+J">Joey Neilsen</a> , et al. (2 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="2501.07415v1-abstract-short" style="display: inline;"> The time-variable emission from the accretion flow of Sgr A*, the supermassive black hole at the Galactic Center, has long been examined in the radio-to-mm, near-infrared (NIR), and X-ray regimes of the electromagnetic spectrum. However, until now, sensitivity and angular resolution have been insufficient in the crucial mid-infrared (MIR) regime. The MIRI instrument on JWST has changed that, and w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.07415v1-abstract-full').style.display = 'inline'; document.getElementById('2501.07415v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.07415v1-abstract-full" style="display: none;"> The time-variable emission from the accretion flow of Sgr A*, the supermassive black hole at the Galactic Center, has long been examined in the radio-to-mm, near-infrared (NIR), and X-ray regimes of the electromagnetic spectrum. However, until now, sensitivity and angular resolution have been insufficient in the crucial mid-infrared (MIR) regime. The MIRI instrument on JWST has changed that, and we report the first MIR detection of Sgr A*. The detection was during a flare that lasted about 40 minutes, a duration similar to NIR and X-ray flares, and the source's spectral index steepened as the flare ended. The steepening suggests synchrotron cooling is an important process for Sgr A*'s variability and implies magnetic field strengths $\sim$40--70 Gauss in the emission zone. Observations at $1.3~\mathrm{mm}$ with the Submillimeter Array revealed a counterpart flare lagging the MIR flare by $\approx$10 minutes. The observations can be self-consistently explained as synchrotron radiation from a single population of gradually cooling high-energy electrons accelerated through (a combination of) magnetic reconnection and/or magnetized turbulence. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.07415v1-abstract-full').style.display = 'none'; document.getElementById('2501.07415v1-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, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.07362">arXiv:2501.07362</a> <span> [<a href="https://arxiv.org/pdf/2501.07362">pdf</a>, <a href="https://arxiv.org/format/2501.07362">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/10.1007/s11433-024-2600-3">10.1007/s11433-024-2600-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Science objectives of the Einstein Probe mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yuan%2C+W">Weimin Yuan</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Lixin Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+H">Hua Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Jin%2C+C">Chichuan Jin</a>, <a href="/search/astro-ph?searchtype=author&query=Jonker%2C+P">Peter Jonker</a>, <a href="/search/astro-ph?searchtype=author&query=Kuulkers%2C+E">Erik Kuulkers</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Y">Yuan Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Nandra%2C+K">Kirpal Nandra</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">Paul O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Piro%2C+L">Luigi Piro</a>, <a href="/search/astro-ph?searchtype=author&query=Rau%2C+A">Arne Rau</a>, <a href="/search/astro-ph?searchtype=author&query=Rea%2C+N">Nanda Rea</a>, <a href="/search/astro-ph?searchtype=author&query=Sanders%2C+J">Jeremy Sanders</a>, <a href="/search/astro-ph?searchtype=author&query=Tao%2C+L">Lian Tao</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Junfeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+X">Xuefeng Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+B">Bing Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuangnan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Ai%2C+S">Shunke Ai</a>, <a href="/search/astro-ph?searchtype=author&query=Buchner%2C+J">Johannes Buchner</a>, <a href="/search/astro-ph?searchtype=author&query=Bulbul%2C+E">Esra Bulbul</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+H">Hechao Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+M">Minghua Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yong Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yu-Peng Chen</a> , et al. (71 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="2501.07362v1-abstract-short" style="display: inline;"> The Einstein Probe (EP) is an interdisciplinary mission of time-domain and X-ray astronomy. Equipped with a wide-field lobster-eye X-ray focusing imager, EP will discover cosmic X-ray transients and monitor the X-ray variability of known sources in 0.5-4 keV, at a combination of detecting sensitivity and cadence that is not accessible to the previous and current wide-field monitoring missions. EP… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.07362v1-abstract-full').style.display = 'inline'; document.getElementById('2501.07362v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.07362v1-abstract-full" style="display: none;"> The Einstein Probe (EP) is an interdisciplinary mission of time-domain and X-ray astronomy. Equipped with a wide-field lobster-eye X-ray focusing imager, EP will discover cosmic X-ray transients and monitor the X-ray variability of known sources in 0.5-4 keV, at a combination of detecting sensitivity and cadence that is not accessible to the previous and current wide-field monitoring missions. EP can perform quick characterisation of transients or outbursts with a Wolter-I X-ray telescope onboard. In this paper, the science objectives of the Einstein Probe mission are presented. EP is expected to enlarge the sample of previously known or predicted but rare types of transients with a wide range of timescales. Among them, fast extragalactic transients will be surveyed systematically in soft X-rays, which include 纬-ray bursts and their variants, supernova shock breakouts, and the predicted X-ray transients associated with binary neutron star mergers. EP will detect X-ray tidal disruption events and outbursts from active galactic nuclei, possibly at an early phase of the flares for some. EP will monitor the variability and outbursts of X-rays from white dwarfs, neutron stars and black holes in our and neighbouring galaxies at flux levels fainter than those detectable by the current instruments, and is expected to discover new objects. A large sample of stellar X-ray flares will also be detected and characterised. In the era of multi-messenger astronomy, EP has the potential of detecting the possible X-ray counterparts of gravitational wave events, neutrino sources, and ultra-high energy 纬-ray and cosmic ray sources. EP is expected to help advance the studies of extreme objects/phenomena and their underlying physical processes revealed in the dynamic X-ray universe, as well as studies in other areas of X-ray astronomy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.07362v1-abstract-full').style.display = 'none'; document.getElementById('2501.07362v1-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, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">67 pages, 24 figures, accepted for publication in SCIENCE CHINA Physics, Mechanics & Astronomy</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.05518">arXiv:2501.05518</a> <span> [<a href="https://arxiv.org/pdf/2501.05518">pdf</a>, <a href="https://arxiv.org/format/2501.05518">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> A multi-frequency study of sub-parsec jets with the Event Horizon Telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=R%C3%B6der%2C+J">Jan R枚der</a>, <a href="/search/astro-ph?searchtype=author&query=Wielgus%2C+M">Maciek Wielgus</a>, <a href="/search/astro-ph?searchtype=author&query=Lobanov%2C+A+P">Andrei P. Lobanov</a>, <a href="/search/astro-ph?searchtype=author&query=Krichbaum%2C+T+P">Thomas P. Krichbaum</a>, <a href="/search/astro-ph?searchtype=author&query=Nair%2C+D+G">Dhanya G. Nair</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+S">Sang-Sung Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Ros%2C+E">Eduardo Ros</a>, <a href="/search/astro-ph?searchtype=author&query=Fish%2C+V+L">Vincent L. Fish</a>, <a href="/search/astro-ph?searchtype=author&query=Blackburn%2C+L">Lindy Blackburn</a>, <a href="/search/astro-ph?searchtype=author&query=Chan%2C+C">Chi-kwan Chan</a>, <a href="/search/astro-ph?searchtype=author&query=Issaoun%2C+S">Sara Issaoun</a>, <a href="/search/astro-ph?searchtype=author&query=Janssen%2C+M">Michael Janssen</a>, <a href="/search/astro-ph?searchtype=author&query=Johnson%2C+M+D">Michael D. Johnson</a>, <a href="/search/astro-ph?searchtype=author&query=Doeleman%2C+S+S">Sheperd S. Doeleman</a>, <a href="/search/astro-ph?searchtype=author&query=Bower%2C+G+C">Geoffrey C. Bower</a>, <a href="/search/astro-ph?searchtype=author&query=Crew%2C+G+B">Geoffrey B. Crew</a>, <a href="/search/astro-ph?searchtype=author&query=Tilanus%2C+R+P+J">Remo P. J. Tilanus</a>, <a href="/search/astro-ph?searchtype=author&query=Savolainen%2C+T">Tuomas Savolainen</a>, <a href="/search/astro-ph?searchtype=author&query=Impellizzeri%2C+C+M+V">C. M. Violette Impellizzeri</a>, <a href="/search/astro-ph?searchtype=author&query=Alberdi%2C+A">Antxon Alberdi</a>, <a href="/search/astro-ph?searchtype=author&query=Baczko%2C+A">Anne-Kathrin Baczko</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%B3mez%2C+J+L">Jos茅 L. G贸mez</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+R">Ru-Sen Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Paraschos%2C+G+F">Georgios F. Paraschos</a>, <a href="/search/astro-ph?searchtype=author&query=Traianou%2C+E">Efthalia Traianou</a> , et al. (265 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="2501.05518v1-abstract-short" style="display: inline;"> The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230 GHz, leading to a number of unique studies on black holes and relativistic jets from active galactic nuclei (AGN). In total, eighteen sources were observed: the main science targets, Sgr A* and M87 along with various calibrators. We… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.05518v1-abstract-full').style.display = 'inline'; document.getElementById('2501.05518v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.05518v1-abstract-full" style="display: none;"> The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230 GHz, leading to a number of unique studies on black holes and relativistic jets from active galactic nuclei (AGN). In total, eighteen sources were observed: the main science targets, Sgr A* and M87 along with various calibrators. We investigated the morphology of the sixteen AGN in the EHT 2017 data set, focusing on the properties of the VLBI cores: size, flux density, and brightness temperature. We studied their dependence on the observing frequency in order to compare it with the Blandford-K枚nigl (BK) jet model. We modeled the source structure of seven AGN in the EHT 2017 data set using linearly polarized circular Gaussian components and collected results for the other nine AGN from dedicated EHT publications, complemented by lower frequency data in the 2-86 GHz range. Then, we studied the dependences of the VLBI core flux density, size, and brightness temperature on the frequency measured in the AGN host frame. We compared the observations with the BK jet model and estimated the magnetic field strength dependence on the distance from the central black hole. Our results indicate a deviation from the standard BK model, particularly in the decrease of the brightness temperature with the observing frequency. Either bulk acceleration of the jet material, energy transfer from the magnetic field to the particles, or both are required to explain the observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.05518v1-abstract-full').style.display = 'none'; document.getElementById('2501.05518v1-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.20842">arXiv:2412.20842</a> <span> [<a href="https://arxiv.org/pdf/2412.20842">pdf</a>, <a href="https://arxiv.org/format/2412.20842">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"> Revisiting the flaring activity in early 2015 of BL Lacertae object S5 0716+714 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ouyang%2C+Z">Zhihao Ouyang</a>, <a href="/search/astro-ph?searchtype=author&query=Xiao%2C+H">Hubing Xiao</a>, <a href="/search/astro-ph?searchtype=author&query=Manganaro%2C+M">Marina Manganaro</a>, <a href="/search/astro-ph?searchtype=author&query=Xie%2C+S">Shangchun Xie</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+J">Jingyu Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">Jianzhen Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Xue%2C+R">Rui Xue</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+G">Gege Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shaohua Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Fan%2C+J">Junhui Fan</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="2412.20842v1-abstract-short" style="display: inline;"> In this work, we analyzed multi-wavelength data of the BL Lac object S5 0716+714 to investigate its emission mechanisms during a flaring state observed in early 2015. We examined the temporal behavior and broadband spectral energy distributions (SEDs) during the flare. The size of the $纬$-ray emission region was estimated based on the variability timescale. To explore the multi-wavelength properti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.20842v1-abstract-full').style.display = 'inline'; document.getElementById('2412.20842v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.20842v1-abstract-full" style="display: none;"> In this work, we analyzed multi-wavelength data of the BL Lac object S5 0716+714 to investigate its emission mechanisms during a flaring state observed in early 2015. We examined the temporal behavior and broadband spectral energy distributions (SEDs) during the flare. The size of the $纬$-ray emission region was estimated based on the variability timescale. To explore the multi-wavelength properties of S5 0716+714, we employed three one-zone models: the SSC model, the SSC plus EC model, and the SSC plus pp interactions model, to reproduce the SEDs. Our findings indicate that while the SSC model can describe the SEDs, it requires an extreme Doppler factor. In contrast, the SSC plus EC model successfully fits the SEDs under the assumption of weak external photon fields but requires a high Doppler factor. Additionally, the SSC plus interactions model also reproduces the SEDs, with $纬$-ray emission originating from $蟺^{0}$ decay. However, this model leads to a jet power that exceeds the Eddington luminosity, which remains plausible due to the flaring state or the presence of a highly collimated jet. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.20842v1-abstract-full').style.display = 'none'; document.getElementById('2412.20842v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 5 figures, accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.15955">arXiv:2412.15955</a> <span> [<a href="https://arxiv.org/pdf/2412.15955">pdf</a>, <a href="https://arxiv.org/format/2412.15955">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"> Continuous evolution of the polarization properties in the transient X-ray pulsar RX J0440.9+4431/LS V +44 17 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+Q+C">Q. C. Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Tao%2C+L">L. Tao</a>, <a href="/search/astro-ph?searchtype=author&query=Tsygankov%2C+S+S">S. Sergey Tsygankov</a>, <a href="/search/astro-ph?searchtype=author&query=Mushtukov%2C+A+A">A. Alexander Mushtukov</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+H">H. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Ge%2C+M+Y">M. Y. Ge</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+H+C">H. C. Li</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S+N">S. N. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+L">L. Zhang</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="2412.15955v1-abstract-short" style="display: inline;"> We present a detailed time-resolved and phase-resolved polarimetric analysis of the transient X-ray pulsar RX J0440.9+4431/LS V +44 17, using data from the Imaging X-ray Polarimetry Explorer (IXPE) during the 2023 giant outburst. We conducted a time-resolved analysis by dividing the data into several intervals for each observation. This analysis reveals a continuous rotation of the phase-averaged… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.15955v1-abstract-full').style.display = 'inline'; document.getElementById('2412.15955v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.15955v1-abstract-full" style="display: none;"> We present a detailed time-resolved and phase-resolved polarimetric analysis of the transient X-ray pulsar RX J0440.9+4431/LS V +44 17, using data from the Imaging X-ray Polarimetry Explorer (IXPE) during the 2023 giant outburst. We conducted a time-resolved analysis by dividing the data into several intervals for each observation. This analysis reveals a continuous rotation of the phase-averaged polarization angle (PA) across the observations performed during the super-critical and sub-critical regimes. To investigate the origin of the PA rotation, we performed a pulse phase-resolved polarimetric analysis over four time intervals, each spanning approximately three days. Applying the rotating vector model (RVM), the geometric parameters of the system were determined for each interval. Despite the short time gap of just $\sim$ 20 days, we observed significant variation in the RVM parameters between the first interval and the subsequent three, indicating the presence of an additional polarized component alongside the RVM component. Using a two-polarized component model with the assumption that this additional component remains constant across pulse phases, we calculated the phase-averaged PA and polarized flux of both the variable and constant components. The phase-averaged PA of each component remained relatively stable over time, but the polarized flux of the constant component decreased, while that of the variable component increased. The observed rotation of the PA is attributed to the gradual shift in the polarized flux ratio between the two components and is not directly related to the different accretion regimes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.15955v1-abstract-full').style.display = 'none'; document.getElementById('2412.15955v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">Acceptance for publication in A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.14960">arXiv:2412.14960</a> <span> [<a href="https://arxiv.org/pdf/2412.14960">pdf</a>, <a href="https://arxiv.org/format/2412.14960">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Terrestrial Very-Long-Baseline Atom Interferometry: Summary of the Second Workshop </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Abdalla%2C+A">Adam Abdalla</a>, <a href="/search/astro-ph?searchtype=author&query=Abe%2C+M">Mahiro Abe</a>, <a href="/search/astro-ph?searchtype=author&query=Abend%2C+S">Sven Abend</a>, <a href="/search/astro-ph?searchtype=author&query=Abidi%2C+M">Mouine Abidi</a>, <a href="/search/astro-ph?searchtype=author&query=Aidelsburger%2C+M">Monika Aidelsburger</a>, <a href="/search/astro-ph?searchtype=author&query=Alibabaei%2C+A">Ashkan Alibabaei</a>, <a href="/search/astro-ph?searchtype=author&query=Allard%2C+B">Baptiste Allard</a>, <a href="/search/astro-ph?searchtype=author&query=Antoniadis%2C+J">John Antoniadis</a>, <a href="/search/astro-ph?searchtype=author&query=Arduini%2C+G">Gianluigi Arduini</a>, <a href="/search/astro-ph?searchtype=author&query=Augst%2C+N">Nadja Augst</a>, <a href="/search/astro-ph?searchtype=author&query=Balamatsias%2C+P">Philippos Balamatsias</a>, <a href="/search/astro-ph?searchtype=author&query=Balaz%2C+A">Antun Balaz</a>, <a href="/search/astro-ph?searchtype=author&query=Banks%2C+H">Hannah Banks</a>, <a href="/search/astro-ph?searchtype=author&query=Barcklay%2C+R+L">Rachel L. Barcklay</a>, <a href="/search/astro-ph?searchtype=author&query=Barone%2C+M">Michele Barone</a>, <a href="/search/astro-ph?searchtype=author&query=Barsanti%2C+M">Michele Barsanti</a>, <a href="/search/astro-ph?searchtype=author&query=Bason%2C+M+G">Mark G. Bason</a>, <a href="/search/astro-ph?searchtype=author&query=Bassi%2C+A">Angelo Bassi</a>, <a href="/search/astro-ph?searchtype=author&query=Bayle%2C+J">Jean-Baptiste Bayle</a>, <a href="/search/astro-ph?searchtype=author&query=Baynham%2C+C+F+A">Charles F. A. Baynham</a>, <a href="/search/astro-ph?searchtype=author&query=Beaufils%2C+Q">Quentin Beaufils</a>, <a href="/search/astro-ph?searchtype=author&query=Beldjoudi%2C+S">Slyan Beldjoudi</a>, <a href="/search/astro-ph?searchtype=author&query=Belic%2C+A">Aleksandar Belic</a>, <a href="/search/astro-ph?searchtype=author&query=Bennetts%2C+S">Shayne Bennetts</a>, <a href="/search/astro-ph?searchtype=author&query=Bernabeu%2C+J">Jose Bernabeu</a> , et al. (285 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="2412.14960v1-abstract-short" style="display: inline;"> This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024, building on the initial discussions during the inaugural workshop held at CERN in March 2023. Like the summary of the first workshop, this document records a critical milestone for the international atom interferometry commun… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.14960v1-abstract-full').style.display = 'inline'; document.getElementById('2412.14960v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.14960v1-abstract-full" style="display: none;"> This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024, building on the initial discussions during the inaugural workshop held at CERN in March 2023. Like the summary of the first workshop, this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.14960v1-abstract-full').style.display = 'none'; document.getElementById('2412.14960v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">Summary of the second Terrestrial Very-Long-Baseline Atom Interferometry Workshop held at Imperial College London: https://indico.cern.ch/event/1369392/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.14850">arXiv:2412.14850</a> <span> [<a href="https://arxiv.org/pdf/2412.14850">pdf</a>, <a href="https://arxiv.org/format/2412.14850">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.nima.2024.170146">10.1016/j.nima.2024.170146 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Long-term stability of scientific X-ray CMOS detectors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Liu%2C+M">Mingjun Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+Q">Qinyu Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Ling%2C+Z">Zhixing Ling</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+C">Chen Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Yuan%2C+W">Weimin Yuan</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang-Nan Zhang</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="2412.14850v1-abstract-short" style="display: inline;"> In recent years, complementary metal-oxide-semiconductor (CMOS) sensors have been demonstrated to have significant potential in X-ray astronomy, where long-term reliability is crucial for space X-ray telescopes. This study examines the long-term stability of a scientific CMOS sensor, focusing on its bias, dark current, readout noise, and X-ray spectral performance. The sensor was initially tested… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.14850v1-abstract-full').style.display = 'inline'; document.getElementById('2412.14850v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.14850v1-abstract-full" style="display: none;"> In recent years, complementary metal-oxide-semiconductor (CMOS) sensors have been demonstrated to have significant potential in X-ray astronomy, where long-term reliability is crucial for space X-ray telescopes. This study examines the long-term stability of a scientific CMOS sensor, focusing on its bias, dark current, readout noise, and X-ray spectral performance. The sensor was initially tested at -30 $^\circ$C for 16 months, followed by accelerated aging at 20 $^\circ$C. After a total aging period of 610 days, the bias map, dark current, readout noise, gain, and energy resolution exhibited no observable degradation. There are less than 50 pixels within the 4 k $\times$ 4 k array which show a decrease of the bias under 50 ms integration time by over 10 digital numbers (DNs). First-order kinetic fitting of the gain evolution predicts a gain degeneration of 0.73% over 3 years and 2.41% over 10 years. These results underscore the long-term reliability of CMOS sensors for application in space missions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.14850v1-abstract-full').style.display = 'none'; document.getElementById('2412.14850v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 7 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nuclear Inst. and Methods in Physics Research, A (2025) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.11460">arXiv:2412.11460</a> <span> [<a href="https://arxiv.org/pdf/2412.11460">pdf</a>, <a href="https://arxiv.org/format/2412.11460">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> </div> </div> <p class="title is-5 mathjax"> Observation of a spectral hardening in cosmic ray boron spectrum with the DAMPE space mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=DAMPE+Collaboration"> DAMPE Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=Alemanno%2C+F">F. Alemanno</a>, <a href="/search/astro-ph?searchtype=author&query=Altomare%2C+C">C. Altomare</a>, <a href="/search/astro-ph?searchtype=author&query=An%2C+Q">Q. An</a>, <a href="/search/astro-ph?searchtype=author&query=Azzarello%2C+P">P. Azzarello</a>, <a href="/search/astro-ph?searchtype=author&query=Barbato%2C+F+C+T">F. C. T. Barbato</a>, <a href="/search/astro-ph?searchtype=author&query=Bernardini%2C+P">P. Bernardini</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Boutin%2C+H">H. Boutin</a>, <a href="/search/astro-ph?searchtype=author&query=Cagnoli%2C+I">I. Cagnoli</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+M+S">M. S. Cai</a>, <a href="/search/astro-ph?searchtype=author&query=Casilli%2C+E">E. Casilli</a>, <a href="/search/astro-ph?searchtype=author&query=Catanzani%2C+E">E. Catanzani</a>, <a href="/search/astro-ph?searchtype=author&query=Chang%2C+J">J. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D+Y">D. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J+L">J. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z+F">Z. F. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z+X">Z. X. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Coppin%2C+P">P. Coppin</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+M+Y">M. Y. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+T+S">T. S. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+Y+X">Y. X. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=De+Mitri%2C+I">I. De Mitri</a>, <a href="/search/astro-ph?searchtype=author&query=de+Palma%2C+F">F. de Palma</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Giovanni%2C+A">A. Di Giovanni</a> , et al. (121 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="2412.11460v2-abstract-short" style="display: inline;"> Secondary cosmic ray fluxes are important probes of the propagation and interaction of high-energy particles in the Galaxy. Recent measurements of primary and secondary cosmic ray nuclei have revealed unexpected spectral features that demand a deeper understanding. In this work we report the direct measurement of the cosmic ray boron spectrum from 10 GeV/n to 8 TeV/n with eight years of data colle… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.11460v2-abstract-full').style.display = 'inline'; document.getElementById('2412.11460v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.11460v2-abstract-full" style="display: none;"> Secondary cosmic ray fluxes are important probes of the propagation and interaction of high-energy particles in the Galaxy. Recent measurements of primary and secondary cosmic ray nuclei have revealed unexpected spectral features that demand a deeper understanding. In this work we report the direct measurement of the cosmic ray boron spectrum from 10 GeV/n to 8 TeV/n with eight years of data collected by the Dark Matter Particle Explorer (DAMPE) mission. The measured spectrum shows an evident hardening at $182\pm24$ GeV/n with a spectral power index of $纬_1 = 3.02 \pm 0.01$ before the break and an index change of $螖纬= 0.31 \pm 0.05$ after the break. A simple power law model is disfavored at a confidence level of 8$蟽$. Compared with the hardenings measured in the DAMPE proton and helium spectra, the secondary boron spectrum hardens roughly twice as much as these primaries, which is consistent with a propagation related mechanism to interpret the spectral hardenings of cosmic rays observed at hundreds of GeV/n. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.11460v2-abstract-full').style.display = 'none'; document.getElementById('2412.11460v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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, 10 figures, submitted to PRL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.10983">arXiv:2412.10983</a> <span> [<a href="https://arxiv.org/pdf/2412.10983">pdf</a>, <a href="https://arxiv.org/format/2412.10983">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad9d0b">10.3847/1538-4357/ad9d0b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The JWST-NIRCam View of Sagittarius C. II. Evidence for Magnetically Dominated HII Regions in the CMZ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bally%2C+J">John Bally</a>, <a href="/search/astro-ph?searchtype=author&query=Crowe%2C+S">Samuel Crowe</a>, <a href="/search/astro-ph?searchtype=author&query=Fedriani%2C+R">Rub茅n Fedriani</a>, <a href="/search/astro-ph?searchtype=author&query=Ginsburg%2C+A">Adam Ginsburg</a>, <a href="/search/astro-ph?searchtype=author&query=Sch%C3%B6del%2C+R">Rainer Sch枚del</a>, <a href="/search/astro-ph?searchtype=author&query=Andersen%2C+M">Morten Andersen</a>, <a href="/search/astro-ph?searchtype=author&query=Tan%2C+J+C">Jonathan C. Tan</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhi-Yun Li</a>, <a href="/search/astro-ph?searchtype=author&query=Nogueras-Lara%2C+F">Francisco Nogueras-Lara</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+Y">Yu Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Law%2C+C">Chi-Yan Law</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Q+D">Q. Daniel Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y">Yichen Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Suinan Zhang</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="2412.10983v1-abstract-short" style="display: inline;"> We present JWST-NIRCam narrow-band, 4.05 $渭$m Brackett-$伪$ images of the Sgr C HII region, located in the Central Molecular Zone (CMZ) of the Galaxy. Unlike any HII region in the Solar vicinity, the Sgr C plasma is dominated by filamentary structure in both Brackett-$伪$ and the radio continuum. Some bright filaments, which form a fractured arc with a radius of about 1.85 pc centered on the Sgr C s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.10983v1-abstract-full').style.display = 'inline'; document.getElementById('2412.10983v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.10983v1-abstract-full" style="display: none;"> We present JWST-NIRCam narrow-band, 4.05 $渭$m Brackett-$伪$ images of the Sgr C HII region, located in the Central Molecular Zone (CMZ) of the Galaxy. Unlike any HII region in the Solar vicinity, the Sgr C plasma is dominated by filamentary structure in both Brackett-$伪$ and the radio continuum. Some bright filaments, which form a fractured arc with a radius of about 1.85 pc centered on the Sgr C star-forming molecular clump, likely trace ionization fronts. The brightest filaments form a `$蟺$-shaped' structure in the center of the HII region. Fainter filaments radiate away from the surface of the Sgr C molecular cloud. The filaments are emitting optically thin free-free emission, as revealed by spectral index measurements from 1.28 GHz (MeerKAT) to 97 GHz (ALMA). But, the negative in-band 1 to 2 GHz spectral index in the MeerKAT data alone reveals the presence of a non-thermal component across the entire Sgr C HII region. We argue that the plasma flow in Sgr C is controlled by magnetic fields, which confine the plasma to rope-like filaments or sheets. This results in the measured non-thermal component of low-frequency radio emission plasma, as well as a plasma $尾$ (thermal pressure divided by magnetic pressure) below 1, even in the densest regions. We speculate that all mature HII regions in the CMZ, and galactic nuclei in general, evolve in a magnetically dominated, low plasma $尾$ regime. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.10983v1-abstract-full').style.display = 'none'; document.getElementById('2412.10983v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">31 pages, 19 figures. Accepted for publication in The Astrophysical Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.09806">arXiv:2412.09806</a> <span> [<a href="https://arxiv.org/pdf/2412.09806">pdf</a>, <a href="https://arxiv.org/format/2412.09806">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"> Bounding the photon mass with gravitationally lensed fast radio bursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chang%2C+C">Chen-Ming Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Wei%2C+J">Jun-Jie Wei</a>, <a href="/search/astro-ph?searchtype=author&query=Meng%2C+K">Ke-Lai Meng</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Song-Bo Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+H">Hao-Xuan Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Geng%2C+J">Jin-Jun Geng</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+X">Xue-Feng Wu</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="2412.09806v1-abstract-short" style="display: inline;"> The gravitational time delays of macro-lenses can be used to constrain the rest mass of the photon with high accuracy. Assuming a point-mass $+$ external shear lens model, we prove that an upper limit of the photon mass can be derived directly from two observables--the time delay $螖t$ and the leading-to-trailing flux ratio $R$ of strongly lensed fast radio bursts (FRBs). Using the observed values… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.09806v1-abstract-full').style.display = 'inline'; document.getElementById('2412.09806v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.09806v1-abstract-full" style="display: none;"> The gravitational time delays of macro-lenses can be used to constrain the rest mass of the photon with high accuracy. Assuming a point-mass $+$ external shear lens model, we prove that an upper limit of the photon mass can be derived directly from two observables--the time delay $螖t$ and the leading-to-trailing flux ratio $R$ of strongly lensed fast radio bursts (FRBs). Using the observed values of $螖t$ and $R$ of a lensed FRB candidate, i.e., FRB 20190308C, as a reference, we obtain a strict upper limit of the photon mass between $m_纬< 5.3 \times {10}^{-42}\,\rm kg$, for a given external shear strength of $纬' = 0.01$, and $m_纬 < 2.1 \times 10^{-41}-2.4 \times 10^{-42}\,\text{kg}$, within the external shear range of $0<纬'<1$. This provides the most stringent limit to date on the photon mass through gravitational lensing time delays, improving by 1 to 2 orders of magnitude the previous results obtained from lensed active galactic nuclei. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.09806v1-abstract-full').style.display = 'none'; document.getElementById('2412.09806v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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, 5 figures, submitted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.09571">arXiv:2412.09571</a> <span> [<a href="https://arxiv.org/pdf/2412.09571">pdf</a>, <a href="https://arxiv.org/format/2412.09571">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> <p class="title is-5 mathjax"> Asymmetric Temperature Variations In Protoplanetary disks: I. Linear Theory, Corotating Spirals, and Ring Formation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+Z">Zhaohuan Zhu</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shangjia Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Johnson%2C+T">Ted Johnson</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="2412.09571v2-abstract-short" style="display: inline;"> Protoplanetary disks can exhibit asymmetric temperature variations due to phenomena such as shadows cast by the inner disk or localized heating by young planets. We investigate the disk features induced by these asymmetric temperature variations. We find that spirals are initially excited, then break into two and reconnect to form rings. By carrying out linear analyses, we first study the spiral l… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.09571v2-abstract-full').style.display = 'inline'; document.getElementById('2412.09571v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.09571v2-abstract-full" style="display: none;"> Protoplanetary disks can exhibit asymmetric temperature variations due to phenomena such as shadows cast by the inner disk or localized heating by young planets. We investigate the disk features induced by these asymmetric temperature variations. We find that spirals are initially excited, then break into two and reconnect to form rings. By carrying out linear analyses, we first study the spiral launching mechanism, and find that the effects of azimuthal temperature variations share similarities with effects of external potentials. Specifically, rotating temperature variations launch steady spiral structures at Lindblad resonances, which corotate with the temperature patterns. When the cooling time exceeds the orbital period, these spiral structures are significantly weakened, and a checkerboard pattern may appear. A temperature variation of about 10\% can induce spirals with order unity density perturbations, comparable to those generated by a thermal mass planet. We then study ring formation and find it is related to the coupling between azimuthal temperature variations and spirals outside the resonances. Such coupling leads to a radially varying angular momentum flux, which produces anomalous wave-driven accretion and forms dense rings separated by the wavelength of the waves. Finally, we speculate that spirals induced by temperature variations may contribute to disk accretion through non-linear wave steepening and dissipation. Overall, considering that irradiation determines the temperature structure of protoplanetary disks, the change of irradiation both spatially or/and temporarily may produce observable effects in protoplanetary disks, especially spirals and rings in outer disks beyond tens of AU. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.09571v2-abstract-full').style.display = 'none'; document.getElementById('2412.09571v2-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 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 13 figures, resubmitted to ApJ after the second round of referee comments</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.08790">arXiv:2412.08790</a> <span> [<a href="https://arxiv.org/pdf/2412.08790">pdf</a>, <a href="https://arxiv.org/format/2412.08790">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Magnetic Fields in Massive Star-forming Regions (MagMaR). V. The Magnetic Field at the Onset of High-mass Star Formation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sanhueza%2C+P">Patricio Sanhueza</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+J">Junhao Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Morii%2C+K">Kaho Morii</a>, <a href="/search/astro-ph?searchtype=author&query=Girart%2C+J+M">Josep Miquel Girart</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Q">Qizhou Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Stephens%2C+I+W">Ian W. Stephens</a>, <a href="/search/astro-ph?searchtype=author&query=Jackson%2C+J+M">James M. Jackson</a>, <a href="/search/astro-ph?searchtype=author&query=Cortes%2C+P+C">Paulo C. Cortes</a>, <a href="/search/astro-ph?searchtype=author&query=Koch%2C+P+M">Patrick M. Koch</a>, <a href="/search/astro-ph?searchtype=author&query=Cyganowski%2C+C+J">Claudia J. Cyganowski</a>, <a href="/search/astro-ph?searchtype=author&query=Saha%2C+P">Piyali Saha</a>, <a href="/search/astro-ph?searchtype=author&query=Beuther%2C+H">Henrik Beuther</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Suinan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Beltran%2C+M+T">Maria T. Beltran</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+Y">Yu Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Olguin%2C+F+A">Fernando A. Olguin</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+X">Xing Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Choudhury%2C+S">Spandan Choudhury</a>, <a href="/search/astro-ph?searchtype=author&query=Pattle%2C+K">Kate Pattle</a>, <a href="/search/astro-ph?searchtype=author&query=andez-Lopez%2C+M+F">Manuel Fern andez-Lopez</a>, <a href="/search/astro-ph?searchtype=author&query=Hwang%2C+J">Jihye Hwang</a>, <a href="/search/astro-ph?searchtype=author&query=Kang%2C+J">Ji-hyun Kang</a>, <a href="/search/astro-ph?searchtype=author&query=Karoly%2C+J">Janik Karoly</a>, <a href="/search/astro-ph?searchtype=author&query=Ginsburg%2C+A">Adam Ginsburg</a>, <a href="/search/astro-ph?searchtype=author&query=Lyo%2C+A+-">A. -Ran Lyo</a> , et al. (14 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="2412.08790v1-abstract-short" style="display: inline;"> A complete understanding of the initial conditions of high-mass star formation and what processes determine multiplicity require the study of the magnetic field (B-field) in young, massive cores. Using ALMA 250 GHz polarization (0.3" = 1000 au) and ALMA 220 GHz high-angular resolution observations (0.05" = 160 au), we have performed a full energy analysis including the B-field at core scales and h… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.08790v1-abstract-full').style.display = 'inline'; document.getElementById('2412.08790v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.08790v1-abstract-full" style="display: none;"> A complete understanding of the initial conditions of high-mass star formation and what processes determine multiplicity require the study of the magnetic field (B-field) in young, massive cores. Using ALMA 250 GHz polarization (0.3" = 1000 au) and ALMA 220 GHz high-angular resolution observations (0.05" = 160 au), we have performed a full energy analysis including the B-field at core scales and have assessed what influences the multiplicity inside a massive core previously believed to be in the prestellar phase. With 31 Msun, the G11.92 MM2 core has a young CS outflow with a dynamical time scale of a few thousand years. At high-resolution, the MM2 core fragments into a binary system with a projected separation of 505 au and a binary mass ratio of 1.14. Using the DCF method with an ADF analysis, we estimate in this core a B-field strength of 6.2 mG and a mass-to-flux ratio of 18. The MM2 core is strongly subvirialized with a virial parameter of 0.064, including the B-field. The high mass-to-flux ratio and low virial parameter indicate that this massive core is very likely undergoing runaway collapse, which is in direct contradiction with the core-accretion model. The MM2 core is embedded in a filament that has a velocity gradient consistent with infall. In line with clump-fed scenarios, the core can grow in mass at a rate of 1.9--5.6 x 10^-4 Msun/yr. In spite of the B-field having only a minor contribution to the total energy budget at core scales, it likely plays a more important role at smaller scales by setting the binary properties. Considering energy ratios and a fragmentation criterion at the core scale, the binary could have been formed by core fragmentation. The binary properties (separation and mass ratio), however, are also consistent with radiation-magnetohydrodynamic simulations with super-Alfvenic, supersonic (or sonic) turbulence that form binaries by disk fragmentation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.08790v1-abstract-full').style.display = 'none'; document.getElementById('2412.08790v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publications in ApJ (9 pages, 3 figures, Appendix)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.05785">arXiv:2412.05785</a> <span> [<a href="https://arxiv.org/pdf/2412.05785">pdf</a>, <a href="https://arxiv.org/format/2412.05785">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"> Quenching and recovery of persistent X-ray emission during a superburst in 4U 1820$-$30 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Peng%2C+Z">Zhijiao Peng</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhaosheng Li</a>, <a href="/search/astro-ph?searchtype=author&query=Pan%2C+Y">Yuanyue Pan</a>, <a href="/search/astro-ph?searchtype=author&query=Fu%2C+T">Tao Fu</a>, <a href="/search/astro-ph?searchtype=author&query=Yu%2C+W">Wenhui Yu</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yupeng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shu Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Falanga%2C+M">Maurizio Falanga</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang-Nan Zhang</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="2412.05785v1-abstract-short" style="display: inline;"> We report the superburst from 4U 1820--30 in 2021 observed by Monitor of All-sky X-ray Image (MAXI) and Neutron star Interior Composition Explorer (NICER). During the tail of the superburst, we found that the NICER light curve unexpectedly increased from 1080 to 2204 ${\rm cts~s^{-1}}$ over 6.89 hr. From the time-resolved superburst spectra, we estimated the burst decay time of $\sim2.7$ hr, the i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.05785v1-abstract-full').style.display = 'inline'; document.getElementById('2412.05785v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.05785v1-abstract-full" style="display: none;"> We report the superburst from 4U 1820--30 in 2021 observed by Monitor of All-sky X-ray Image (MAXI) and Neutron star Interior Composition Explorer (NICER). During the tail of the superburst, we found that the NICER light curve unexpectedly increased from 1080 to 2204 ${\rm cts~s^{-1}}$ over 6.89 hr. From the time-resolved superburst spectra, we estimated the burst decay time of $\sim2.7$ hr, the ignition column depth of $\sim0.3\times 10^{12}~{\rm g ~cm^{-2}}$, the energy release per unit mass of $\sim1.7\times 10^{17}~{\rm erg~g^{-1}}$, the fluence of $\sim4.5\times 10^{-4}~{\rm erg~cm^{-2}}$, and the total energy release of $\sim3.8\times10^{42}$ erg. Notably, we found a gradual increase in the Componization flux from $8.9\times 10^{-10}~{\rm erg~s^{-1}~cm^{-2}}$ to the pre-burst level during the superburst. This increase can be interpreted as a consequence of superburst radiation depleting the inner accretion disk, leading to a near-complete quenching of the persistent emission. As the burst radiation decayed, the inner accretion disk gradually returned to its pre-burst state, as evidenced by the best-fit spectral parameters. Additionally, we observed a prominent absorption line that exhibited a gravitational redshift, shifting from 4.16 to 3.60 keV during the recovery phase of persistent emission. This absorption feature likely originates from the inner accretion disk rather than from burst emission on the neutron star (NS) surface. The observed changes in the absorption line energy suggest that the inner disk approached the NS to a distance as close as $\sim16$ km. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.05785v1-abstract-full').style.display = 'none'; document.getElementById('2412.05785v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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, 10 figures, submitted to ApJ, comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.05779">arXiv:2412.05779</a> <span> [<a href="https://arxiv.org/pdf/2412.05779">pdf</a>, <a href="https://arxiv.org/format/2412.05779">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A comprehensive study of type I (thermonuclear) bursts in the new transient SRGA J144459.2$-$604207 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Fu%2C+T">Tao Fu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhaosheng Li</a>, <a href="/search/astro-ph?searchtype=author&query=Pan%2C+Y">Yuanyue Pan</a>, <a href="/search/astro-ph?searchtype=author&query=Ji%2C+L">Long Ji</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yupeng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Kuiper%2C+L">Lucien Kuiper</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">Duncan K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Falanga%2C+M">Maurizio Falanga</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+R">Renxin Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+X">Xiaobo Li</a>, <a href="/search/astro-ph?searchtype=author&query=Ge%2C+M">Mingyu Ge</a>, <a href="/search/astro-ph?searchtype=author&query=Song%2C+L+M">L. M. Song</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shu Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang-Nan Zhang</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="2412.05779v1-abstract-short" style="display: inline;"> We report analysis of $\textit{Insight}$-HXMT observations of the newly discovered accreting millisecond pulsar SRGA J144459.2$-$604207. During the outburst, detected in 2024 February by $\textit{eROSITA}$, the broadband persistent spectrum was well fitted by an absorbed Comptonization model. We detected 60 type I X-ray bursts in the $\textit{Insight}$-HXMT medium energy (ME) data, and 37 were als… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.05779v1-abstract-full').style.display = 'inline'; document.getElementById('2412.05779v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.05779v1-abstract-full" style="display: none;"> We report analysis of $\textit{Insight}$-HXMT observations of the newly discovered accreting millisecond pulsar SRGA J144459.2$-$604207. During the outburst, detected in 2024 February by $\textit{eROSITA}$, the broadband persistent spectrum was well fitted by an absorbed Comptonization model. We detected 60 type I X-ray bursts in the $\textit{Insight}$-HXMT medium energy (ME) data, and 37 were also detected with the low-energy (LE) telescope. By superimposing the $\textit{Insight}$-HXMT/LE/ME/HE light curves of 37 bursts with similar profiles and intensities, we measured a deficit of X-rays in the 40$-$70 keV energy band. By analyzing the time-resolved X-ray burst spectra, we determine the mean ratio of persistent to burst flux of $伪=71\pm7$. We estimate the average hydrogen mass fraction in the fuel at ignition, as $\bar{X} = 0.342 \pm 0.033$, and constrain the burst fuel composition as $X_0\lesssim0.4$. We found that 14 out of 60 X-ray bursts exhibited photospheric expansion, and thus we estimated the distance to the source as $10.03\pm 0.71$ kpc. Combined with $\textit{IXPE}$ observations, the burst recurrence time were increasing from 1.55 to 8 hr as the local mass accretion rate decreasing, which can be described as $螖T_{\rm rec}\sim \dot{m}^{-0.91\pm0.02}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.05779v1-abstract-full').style.display = 'none'; document.getElementById('2412.05779v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 9 figures, submitted to ApJ, comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.05046">arXiv:2412.05046</a> <span> [<a href="https://arxiv.org/pdf/2412.05046">pdf</a>, <a href="https://arxiv.org/format/2412.05046">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"> Observation of Cosmic-Ray Anisotropy in the Southern Hemisphere with Twelve Years of Data Collected by the IceCube Neutrino Observatory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Abbasi%2C+R">R. Abbasi</a>, <a href="/search/astro-ph?searchtype=author&query=Ackermann%2C+M">M. Ackermann</a>, <a href="/search/astro-ph?searchtype=author&query=Adams%2C+J">J. Adams</a>, <a href="/search/astro-ph?searchtype=author&query=Agarwalla%2C+S+K">S. K. Agarwalla</a>, <a href="/search/astro-ph?searchtype=author&query=Aguado%2C+T">T. Aguado</a>, <a href="/search/astro-ph?searchtype=author&query=Aguilar%2C+J+A">J. A. Aguilar</a>, <a href="/search/astro-ph?searchtype=author&query=Ahlers%2C+M">M. Ahlers</a>, <a href="/search/astro-ph?searchtype=author&query=Alameddine%2C+J+M">J. M. Alameddine</a>, <a href="/search/astro-ph?searchtype=author&query=Amin%2C+N+M">N. M. Amin</a>, <a href="/search/astro-ph?searchtype=author&query=Andeen%2C+K">K. Andeen</a>, <a href="/search/astro-ph?searchtype=author&query=Arg%C3%BCelles%2C+C">C. Arg眉elles</a>, <a href="/search/astro-ph?searchtype=author&query=Ashida%2C+Y">Y. Ashida</a>, <a href="/search/astro-ph?searchtype=author&query=Athanasiadou%2C+S">S. Athanasiadou</a>, <a href="/search/astro-ph?searchtype=author&query=Axani%2C+S+N">S. N. Axani</a>, <a href="/search/astro-ph?searchtype=author&query=Babu%2C+R">R. Babu</a>, <a href="/search/astro-ph?searchtype=author&query=Bai%2C+X">X. Bai</a>, <a href="/search/astro-ph?searchtype=author&query=V.%2C+A+B">A. Balagopal V.</a>, <a href="/search/astro-ph?searchtype=author&query=Baricevic%2C+M">M. Baricevic</a>, <a href="/search/astro-ph?searchtype=author&query=Barwick%2C+S+W">S. W. Barwick</a>, <a href="/search/astro-ph?searchtype=author&query=Bash%2C+S">S. Bash</a>, <a href="/search/astro-ph?searchtype=author&query=Basu%2C+V">V. Basu</a>, <a href="/search/astro-ph?searchtype=author&query=Bay%2C+R">R. Bay</a>, <a href="/search/astro-ph?searchtype=author&query=Beatty%2C+J+J">J. J. Beatty</a>, <a href="/search/astro-ph?searchtype=author&query=Tjus%2C+J+B">J. Becker Tjus</a>, <a href="/search/astro-ph?searchtype=author&query=Beise%2C+J">J. Beise</a> , et al. (413 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="2412.05046v1-abstract-short" style="display: inline;"> We analyzed the 7.92$\times 10^{11}$ cosmic-ray-induced muon events collected by the IceCube Neutrino Observatory from May 13, 2011, when the fully constructed experiment started to take data, to May 12, 2023. This dataset provides an up-to-date cosmic-ray arrival direction distribution in the Southern Hemisphere with unprecedented statistical accuracy covering more than a full period length of a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.05046v1-abstract-full').style.display = 'inline'; document.getElementById('2412.05046v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.05046v1-abstract-full" style="display: none;"> We analyzed the 7.92$\times 10^{11}$ cosmic-ray-induced muon events collected by the IceCube Neutrino Observatory from May 13, 2011, when the fully constructed experiment started to take data, to May 12, 2023. This dataset provides an up-to-date cosmic-ray arrival direction distribution in the Southern Hemisphere with unprecedented statistical accuracy covering more than a full period length of a solar cycle. Improvements in Monte Carlo event simulation and better handling of year-to-year differences in data processing significantly reduce systematic uncertainties below the level of statistical fluctuations compared to the previously published results. We confirm the observation of a change in the angular structure of the cosmic-ray anisotropy between 10 TeV and 1 PeV, more specifically in the 100-300 TeV energy range. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.05046v1-abstract-full').style.display = 'none'; document.getElementById('2412.05046v1-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 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.02229">arXiv:2412.02229</a> <span> [<a href="https://arxiv.org/pdf/2412.02229">pdf</a>, <a href="https://arxiv.org/format/2412.02229">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> </div> <p class="title is-5 mathjax"> First Pulsar Polarization Array Limits on Ultralight Axion-like Dark Matter </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Xue%2C+X">Xiao Xue</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+S">Shi Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Luu%2C+H+N">Hoang Nhan Luu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Ren%2C+J">Jing Ren</a>, <a href="/search/astro-ph?searchtype=author&query=Shu%2C+J">Jing Shu</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+Y">Yue Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Zic%2C+A">Andrew Zic</a>, <a href="/search/astro-ph?searchtype=author&query=Bhat%2C+N+D+R">N. D. Ramesh Bhat</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z">Zu-Cheng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Y">Yi Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Hobbs%2C+G">George Hobbs</a>, <a href="/search/astro-ph?searchtype=author&query=Kapur%2C+A">Agastya Kapur</a>, <a href="/search/astro-ph?searchtype=author&query=Manchester%2C+R+N">Richard N. Manchester</a>, <a href="/search/astro-ph?searchtype=author&query=Mandow%2C+R">Rami Mandow</a>, <a href="/search/astro-ph?searchtype=author&query=Mishra%2C+S">Saurav Mishra</a>, <a href="/search/astro-ph?searchtype=author&query=Reardon%2C+D+J">Daniel J. Reardon</a>, <a href="/search/astro-ph?searchtype=author&query=Russell%2C+C+J">Christopher J. Russell</a>, <a href="/search/astro-ph?searchtype=author&query=Shannon%2C+R+M">Ryan M. Shannon</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+S">Shuangqiang Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+L">Lei Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Songbo Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+X">Xingjiang Zhu</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="2412.02229v1-abstract-short" style="display: inline;"> We conduct the first-ever Pulsar Polarization Array (PPA) analysis to detect the ultralight Axion-Like Dark Matter (ALDM) using the polarization data of 22 millisecond pulsars from the third data release of Parkes Pulsar Timing Array. As one of the major dark matter candidates, the ultralight ALDM exhibits a pronounced wave nature on astronomical scales and offers a promising solution to small-sca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02229v1-abstract-full').style.display = 'inline'; document.getElementById('2412.02229v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.02229v1-abstract-full" style="display: none;"> We conduct the first-ever Pulsar Polarization Array (PPA) analysis to detect the ultralight Axion-Like Dark Matter (ALDM) using the polarization data of 22 millisecond pulsars from the third data release of Parkes Pulsar Timing Array. As one of the major dark matter candidates, the ultralight ALDM exhibits a pronounced wave nature on astronomical scales and offers a promising solution to small-scale structure issues within local galaxies. While the linearly polarized pulsar light travels through the ALDM galactic halo, its position angle (PA) can be subject to an oscillation induced by the ALDM Chern-Simons coupling with electromagnetic field. The PPA is thus especially suited for detecting the ultralight ALDM by correlating polarization data across the arrayed pulsars. To accomplish this task, we develop an advanced Bayesian analysis framework that allows us to construct pulsar PA residual time series, model noise contributions properly and search for pulsar cross-correlations. We find that for an ALDM density of $蟻_0=0.4\,\textrm{GeV}/\textrm{cm}^3$, the Parkes PPA offers the best global limits on the ALDM Chern-Simons coupling, namely $\lesssim 10^{-13.5}-10^{-12.2}~{\rm GeV}^{-1}$, for the mass range of $10^{-22} - 10^{-21}~{\rm eV}$. The crucial role of pulsar cross-correlation in recognizing the nature of the derived limits is also highlighted. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02229v1-abstract-full').style.display = 'none'; document.getElementById('2412.02229v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6+15 pages, 10 figures, 2 tables, submitted to the 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/2412.02055">arXiv:2412.02055</a> <span> [<a href="https://arxiv.org/pdf/2412.02055">pdf</a>, <a href="https://arxiv.org/ps/2412.02055">ps</a>, <a href="https://arxiv.org/format/2412.02055">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> </div> <p class="title is-5 mathjax"> The hidden magnetic structures of a solar intermediate filament revealed by the injected flare material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yan%2C+X+L">X. L. Yan</a>, <a href="/search/astro-ph?searchtype=author&query=Xue%2C+Z+K">Z. K. Xue</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J+C">J. C. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+L+H">L. H. Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Ji%2C+K+F">K. F. Ji</a>, <a href="/search/astro-ph?searchtype=author&query=Kong%2C+D+F">D. F. Kong</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+Z">Z. Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Q+L">Q. L. Li</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+L+P">L. P. Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+X+S">X. S. Zhang</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="2412.02055v1-abstract-short" style="display: inline;"> Solar filaments are spectacular objects in the solar atmosphere, consisting of accumulations of cool, dense, and partially ionized plasma suspended in the hot solar corona against gravity. The magnetic structures that support the filament material remain elusive, partly due to the lack of high resolution magnetic field measurements in the chromosphere and corona. In this study, we reconstruct the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02055v1-abstract-full').style.display = 'inline'; document.getElementById('2412.02055v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.02055v1-abstract-full" style="display: none;"> Solar filaments are spectacular objects in the solar atmosphere, consisting of accumulations of cool, dense, and partially ionized plasma suspended in the hot solar corona against gravity. The magnetic structures that support the filament material remain elusive, partly due to the lack of high resolution magnetic field measurements in the chromosphere and corona. In this study, we reconstruct the magnetic structures of a solar intermediate filament using EUV observations and two different methods, to follow the injection of hot material from a B-class solar flare. Our analysis reveals the fine-scale magnetic structures of the filament, including a compact set of mutually wrapped magnetic fields encasing the cool filament material, two groups of helical magnetic structures intertwining with the main filament, and a series of arched magnetic loops positioned along the filament. Additionally, we also find that the northern footpoints of the helical structures are rooted in the same location, while their southern footpoints are rooted in different areas. The results obtained in this study offer new insights into the formation and eruption mechanisms of solar filaments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02055v1-abstract-full').style.display = 'none'; document.getElementById('2412.02055v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">23 pages, 13 figures, accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.01593">arXiv:2412.01593</a> <span> [<a href="https://arxiv.org/pdf/2412.01593">pdf</a>, <a href="https://arxiv.org/format/2412.01593">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> ALMA Observations of Massive Clouds in the Central Molecular Zone: External-Pressure-Confined Dense Cores and Salpeter-like Core Mass Functions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Z">Zhenying Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+X">Xing Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+T">Tie Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Qin%2C+S">Sheng-Li Qin</a>, <a href="/search/astro-ph?searchtype=author&query=Ginsburg%2C+A">Adam Ginsburg</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+Y">Yu Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+H+B">Hauyu Baobab Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Walker%2C+D+L">Daniel L. Walker</a>, <a href="/search/astro-ph?searchtype=author&query=Tang%2C+X">Xindi Tang</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+S">Shanghuo Li</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Q">Qizhou Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Pillai%2C+T">Thushara Pillai</a>, <a href="/search/astro-ph?searchtype=author&query=Kauffmann%2C+J">Jens Kauffmann</a>, <a href="/search/astro-ph?searchtype=author&query=Battersby%2C+C">Cara Battersby</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+S">Siyi Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Suinan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Gu%2C+Q">Qi-Lao Gu</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+F">Fengwei Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+W">Wenyu Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+X">Xunchuan Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Li Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Luo%2C+Q">Qiu-yi Luo</a>, <a href="/search/astro-ph?searchtype=author&query=Mai%2C+X">Xiaofeng Mai</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zi-yang Li</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+D">Dongting Yang</a> , et al. (3 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="2412.01593v1-abstract-short" style="display: inline;"> We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 (1.3 mm) observations of dense cores in three massive molecular clouds within the Central Molecular Zone (CMZ) of the Milky Way, including the Dust Ridge cloud e, Sgr C, and the 20 km s-1 cloud, at a spatial resolution of 2000 au. Among the 834 cores identified from the 1.3 mm continuum, we constrain temperatures and linewidths… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.01593v1-abstract-full').style.display = 'inline'; document.getElementById('2412.01593v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.01593v1-abstract-full" style="display: none;"> We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 (1.3 mm) observations of dense cores in three massive molecular clouds within the Central Molecular Zone (CMZ) of the Milky Way, including the Dust Ridge cloud e, Sgr C, and the 20 km s-1 cloud, at a spatial resolution of 2000 au. Among the 834 cores identified from the 1.3 mm continuum, we constrain temperatures and linewidths of 253 cores using local thermodynamic equilibrium (LTE) methods to fit the H2CO and/or CH3CN spectra. We determine their masses using the 1.3 mm dust continuum and derived temperatures, and then evaluate their virial parameters using the H2CO and/or CH3CN linewidths and construct the core mass functions (CMFs). We find that the contribution of external pressure is crucial for the virial equilibrium of the dense cores in the three clouds, which contrasts with the environment in the Galactic disk where dense cores are already bound even without the contribution of external pressure. We also find that the CMFs show a Salpeter-like slope in the high-mass (>~3-6 Msun) end, a change from previous works with our new temperature estimates. Combined with the possible top-heavy initial mass functions (IMFs) in the CMZ, our result suggests that gas accretion and further fragmentation may play important roles in transforming the CMF to the IMF. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.01593v1-abstract-full').style.display = 'none'; document.getElementById('2412.01593v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">ApJ accepted. The 4 figure sets with numerous panels will be published on the AAS journal website</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.19382">arXiv:2411.19382</a> <span> [<a href="https://arxiv.org/pdf/2411.19382">pdf</a>, <a href="https://arxiv.org/format/2411.19382">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Can the central compact object in HESS J1731--347 be indeed the lightest neutron star observed? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shu-Rui Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Rueda%2C+J+A">Jorge A. Rueda</a>, <a href="/search/astro-ph?searchtype=author&query=Negreiros%2C+R">Rodrigo Negreiros</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.19382v1-abstract-short" style="display: inline;"> The exceptionally low mass of $0.77_{-0.17}^{+0.2} M_{\odot}$ for the central compact object (CCO) XMMU J173203.3 -- 344518 (XMMU J1732) in the supernova remnant (SNR) HESS J1731 -- 347 challenges standard neutron star (NS) formation models. The nearby post-AGB star IRAS 17287 -- 3443 ($\approx 0.6 M_\odot$), also within the SNR, enriches the scenario. To address this puzzle, we advance the possib… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.19382v1-abstract-full').style.display = 'inline'; document.getElementById('2411.19382v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.19382v1-abstract-full" style="display: none;"> The exceptionally low mass of $0.77_{-0.17}^{+0.2} M_{\odot}$ for the central compact object (CCO) XMMU J173203.3 -- 344518 (XMMU J1732) in the supernova remnant (SNR) HESS J1731 -- 347 challenges standard neutron star (NS) formation models. The nearby post-AGB star IRAS 17287 -- 3443 ($\approx 0.6 M_\odot$), also within the SNR, enriches the scenario. To address this puzzle, we advance the possibility that the gravitational collapse of a rotating pre-SN iron core ($\approx 1.2 M_\odot$) could result in a low-mass NS. We show that angular momentum conservation during the collapse of an iron core rotating at $\approx 45\%$ of the Keplerian limit results in a mass loss of $\approx 0.3 M_\odot$, producing a stable newborn NS of $\approx 0.9 M_\odot$. Considering the possible spin-down, this indicates that the NS is now slowly rotating, thus fulfilling the observed mass-radius relation. Additionally, the NS's surface temperature ($\approx 2 \times 10^6$ K) aligns with canonical thermal evolution for its $\approx 4.5$ kyr age. We propose the pre -- SN star, likely an ultra-stripped core of $\approx 4.2 M_\odot$, formed a tidally locked binary with IRAS 17287 -- 3443, having a 1.43-day orbital period. The supernova led to a $\approx 3 M_\odot$ mass loss, imparting a kick velocity $\lesssim 670$ km s$^{-1}$, which disrupted the binary. This scenario explains the observed 0.3 pc offset between XMMU J1732 and IRAS 17287 -- 3443 and supports the possibility of CCOs forming in binaries, with rotation playing a key role in core-collapse, and the CCO XMMU J1732 being the lightest NS ever observed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.19382v1-abstract-full').style.display = 'none'; document.getElementById('2411.19382v1-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 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">Accepted for publication in ApJ, comments are welcome!</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.17462">arXiv:2411.17462</a> <span> [<a href="https://arxiv.org/pdf/2411.17462">pdf</a>, <a href="https://arxiv.org/format/2411.17462">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Nuclear Theory">nucl-th</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Lattice">hep-lat</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Nuclear Experiment">nucl-ex</span> </div> </div> <p class="title is-5 mathjax"> Lattice simulation of nucleon distribution and shell closure in the proton-rich nucleus $^{22}$Si </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Elhatisari%2C+S">Serdar Elhatisari</a>, <a href="/search/astro-ph?searchtype=author&query=Mei%C3%9Fner%2C+U">Ulf-G. Mei脽ner</a>, <a href="/search/astro-ph?searchtype=author&query=Shen%2C+S">Shihang Shen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.17462v1-abstract-short" style="display: inline;"> The proton-rich nucleus $^{22}$Si is studied using Nuclear Lattice Effective Field Theory with high-fidelity chiral forces. Our results indicate that $^{22}$Si is more tightly bound than $^{20}$Mg, thereby excluding the possibility of two-proton emission. The $Z = 14$ shell closure in $^{22}$Si is supported by the evolution of the $2^+$ state in the neighboring nuclei. We then focus on the charge… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.17462v1-abstract-full').style.display = 'inline'; document.getElementById('2411.17462v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.17462v1-abstract-full" style="display: none;"> The proton-rich nucleus $^{22}$Si is studied using Nuclear Lattice Effective Field Theory with high-fidelity chiral forces. Our results indicate that $^{22}$Si is more tightly bound than $^{20}$Mg, thereby excluding the possibility of two-proton emission. The $Z = 14$ shell closure in $^{22}$Si is supported by the evolution of the $2^+$ state in the neighboring nuclei. We then focus on the charge radius and spatial distribution information of $^{22}$Si, considering the novel phenomena that may emerge due to the small two-proton separation energy and the shell closure. We present the distribution of the $14$ protons and $8$ neutrons obtained from our lattice simulation, revealing insights into the spatial arrangement of the nucleons. Moreover, the spatial localization of the outermost proton and neutron suggests that $^{22}$Si is a doubly magic nucleus. Furthermore, we develop the pinhole method based on the harmonic oscillator basis, which gives insight into the nuclear structure in terms of the shell model picture from lattice simulations. Our calculated occupation numbers support that $Z = 14$ and $N = 8$ are the shell closures and show that the $蟺1s_{1/2}$ orbital component is minor in $^{22}$Si. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.17462v1-abstract-full').style.display = 'none'; document.getElementById('2411.17462v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 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">5+4 pages, 3+2 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/2411.16174">arXiv:2411.16174</a> <span> [<a href="https://arxiv.org/pdf/2411.16174">pdf</a>, <a href="https://arxiv.org/format/2411.16174">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"> Long Pulse by Short Central Engine: Prompt emission from expanding dissipation rings in the jet front of gamma-ray bursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yi%2C+S">Shu-Xu Yi</a>, <a href="/search/astro-ph?searchtype=author&query=Yorgancioglu%2C+E+S">Emre Seyit Yorgancioglu</a>, <a href="/search/astro-ph?searchtype=author&query=Xiong%2C+S+-">S. -L. Xiong</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S+-">S. -N. Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.16174v2-abstract-short" style="display: inline;"> Recent observations have challenged the long-held opinion that the duration of gamma-ray burst (GRB) prompt emission is determined by the activity epochs of the central engine. Specifically, the observations of GRB 230307A have revealed a different scenario in which the duration of the prompt emission is predominantly governed by the energy dissipation process following a brief initial energy inje… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.16174v2-abstract-full').style.display = 'inline'; document.getElementById('2411.16174v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.16174v2-abstract-full" style="display: none;"> Recent observations have challenged the long-held opinion that the duration of gamma-ray burst (GRB) prompt emission is determined by the activity epochs of the central engine. Specifically, the observations of GRB 230307A have revealed a different scenario in which the duration of the prompt emission is predominantly governed by the energy dissipation process following a brief initial energy injection from the central engine. In this paper, we explore a mechanism where the energy injection from the central engine initially causes turbulence in a small region and radiates locally. This turbulence then propagates to more distant regions and radiates. Consequently, the emission regions form concentric rings that extend outward. Using an idealized toy model, we show that such a mechanism, initiated by a pulsed energy injection, can produce a prompt emission light curve resembling a single broad pulse exhibiting the typical softer-wider/softer-later feature. Under some parameters, the main characteristics of the GRB 230307A spectra and light curves can be reproduced by the toy model. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.16174v2-abstract-full').style.display = 'none'; document.getElementById('2411.16174v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted to ApJL;</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.13750">arXiv:2411.13750</a> <span> [<a href="https://arxiv.org/pdf/2411.13750">pdf</a>, <a href="https://arxiv.org/ps/2411.13750">ps</a>, <a href="https://arxiv.org/format/2411.13750">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"> Radiation mechanism of twin kilohertz quasi-periodic oscillations in neutron star low mass X-ray binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Shi%2C+C">ChangSheng Shi</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+G">GuoBao Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">ShuangNan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+X">XiangDong Li</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.13750v1-abstract-short" style="display: inline;"> Context: The connection between quasi-periodic oscillations (QPOs) and magnetic fields has been investigated across various celestial bodies. Magnetohydrodynamics (MHD) waves have been employed to explain the simultaneous upper and lower kilohertz (kHz) QPOs. Nevertheless, the intricate and undefined formation pathways of twin kHz QPOs present a compelling avenue for exploration. This area of stud… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.13750v1-abstract-full').style.display = 'inline'; document.getElementById('2411.13750v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.13750v1-abstract-full" style="display: none;"> Context: The connection between quasi-periodic oscillations (QPOs) and magnetic fields has been investigated across various celestial bodies. Magnetohydrodynamics (MHD) waves have been employed to explain the simultaneous upper and lower kilohertz (kHz) QPOs. Nevertheless, the intricate and undefined formation pathways of twin kHz QPOs present a compelling avenue for exploration. This area of study holds great interest as it provides an opportunity to derive crucial parameters related to compact stars. Aims:We strives to develop a self-consistent model elucidating the radiation mechanism of twin kHz QPOs, subsequently comparing it with observations. Methods: A sample of 28 twin kHz QPOs observed from the X-ray binary 4U 1636--53 are used to compare with the results of the MCMC calculations according to our model of the radiation mechanism of twin kHz QPOs, which is related to twin MHD waves. Results: We obtain twenty-eight groups of parameters of 4U 1636--53 and a tight exponential fit between the flux and the temperature of seed photons to Compton up-scattering and find that the electron temperature in the corona around the neutron star decreases with the increasing temperature of the seed photons. Conclusions: The origin of twin kHz QPOs can be attributed to dual disturbances arising from twin MHD waves generated at the innermost radius of an accretion disc. The seed photons can be transported through a high temperature corona and Compton up-scattered. The variability of the photons with the frequencies of twin MHD waves can lead to the observed twin kHz QPOs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.13750v1-abstract-full').style.display = 'none'; document.getElementById('2411.13750v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.13122">arXiv:2411.13122</a> <span> [<a href="https://arxiv.org/pdf/2411.13122">pdf</a>, <a href="https://arxiv.org/format/2411.13122">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Identifying the Galactic Substructures in 5D Space Using All-sky RR Lyrae Stars in Gaia DR3 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sun%2C+S">Shenglan Sun</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+F">Fei Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+H">Huawei Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Xue%2C+X">Xiang-Xiang Xue</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y">Yang Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+R">Ruizhi Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Rix%2C+H">Hans-Walter Rix</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+X">Xinyi Li</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+G">Gaochao Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+L">Lan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+C">Chengqun Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuo Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.13122v1-abstract-short" style="display: inline;"> Motivated by the vast gap between photometric and spectroscopic data volumes, there is great potential in using 5D kinematic information to identify and study substructures of the Milky Way. We identify substructures in the Galactic halo using 46,575 RR Lyrae stars (RRLs) from Gaia DR3 with the photometric metallicities and distances newly estimated by Li et al. (2023). Assuming a Gaussian prior d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.13122v1-abstract-full').style.display = 'inline'; document.getElementById('2411.13122v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.13122v1-abstract-full" style="display: none;"> Motivated by the vast gap between photometric and spectroscopic data volumes, there is great potential in using 5D kinematic information to identify and study substructures of the Milky Way. We identify substructures in the Galactic halo using 46,575 RR Lyrae stars (RRLs) from Gaia DR3 with the photometric metallicities and distances newly estimated by Li et al. (2023). Assuming a Gaussian prior distribution of radial velocity, we calculate the orbital distribution characterized by the integrals of motion for each RRL based on its 3D positions, proper motions and corresponding errors, and then apply the friends-of-friends algorithm to identify groups moving along similar orbits. We have identified several known substructures, including Sagittarius (Sgr) Stream, Hercules-Aquila Cloud (HAC), Virgo Overdensity (VOD), Gaia-Enceladus-Sausage (GES), Orphan-Chenab stream, Cetus-Palca, Helmi Streams, Sequoia, Wukong and Large Magellanic Cloud (LMC) leading arm, along with 18 unknown groups. Our findings indicate that HAC and VOD have kinematic and chemical properties remarkably similar to GES, with most HAC and VOD members exhibiting eccentricity as high as GES, suggesting that they may share a common origin with GES. The ability to identify the low mass and spatially dispersed substructures further demonstrates the potential of our method, which breaks the limit of spectroscopic survey and is competent to probe the substructures in the whole Galaxy. Finally, we have also identified 18 unknown groups with good spatial clustering and proper motion consistency, suggesting more excavation of Milky Way substructures in the future with only 5D data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.13122v1-abstract-full').style.display = 'none'; document.getElementById('2411.13122v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 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">23 pages, 19 figures, 4 tables, accepted for publication in ApJ, version before language edition</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.11373">arXiv:2411.11373</a> <span> [<a href="https://arxiv.org/pdf/2411.11373">pdf</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/ad8353">10.3847/1538-4357/ad8353 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Study of Jet Formation Mechanism in Fermi Blazars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Xie%2C+S">Shangchun Xie</a>, <a href="/search/astro-ph?searchtype=author&query=Ouyang%2C+Z">Zhihao Ouyang</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+J">Jingyu Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Xiao%2C+H">Hubing Xiao</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shaohua Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yongyun Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Luo%2C+Z">Zhijian Luo</a>, <a href="/search/astro-ph?searchtype=author&query=Fan%2C+J">Junhui Fan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.11373v1-abstract-short" style="display: inline;"> The origin of jet launching mainly comes from two mechanisms: the BZ mechanism and the BP mechanism. However, it is in debate which one is dominating in blazars. In this work, we used a sample of 937 Fermi blazars to study the jet formation mechanism. We studied the correlation between the jet power and the accretion rate, as well as the comparison between jet power estimated by spectral energy di… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11373v1-abstract-full').style.display = 'inline'; document.getElementById('2411.11373v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.11373v1-abstract-full" style="display: none;"> The origin of jet launching mainly comes from two mechanisms: the BZ mechanism and the BP mechanism. However, it is in debate which one is dominating in blazars. In this work, we used a sample of 937 Fermi blazars to study the jet formation mechanism. We studied the correlation between the jet power and the accretion rate, as well as the comparison between jet power estimated by spectral energy distribution (SED) fitting and that estimated by theoretical formula and radio flux density. Our results suggest that there is no correlation between jet power estimated by SED fitting and the accretion rate for BL Lacs, while a positive and weak correlation exists for flat spectrum radio quasars (FSRQs). Meanwhile, to confirm whether the BP and BZ mechanism is sufficient to launch the jet for FSRQs and BL Lacs, we compare the theoretical jet power with that estimated by SED fitting, as well as that by radio emission. We found that the jet power for most of the two subclasses estimated by SED fitting cannot be explained by either the BP or BZ mechanism. While the jet power for most FSRQs estimated by radio flux density can be explained by the BP mechanism, and most BL Lacs can be explained by the BZ mechanism. We also found that FSRQs have higher accretion rates than BL Lacs, implying different accretion disks around their central black holes: FSRQs typically have standard disks, while BL Lacs usually have advection-dominated accretion flow disks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11373v1-abstract-full').style.display = 'none'; document.getElementById('2411.11373v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 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">10 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ApJ,2024,976,78 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.11220">arXiv:2411.11220</a> <span> [<a href="https://arxiv.org/pdf/2411.11220">pdf</a>, <a href="https://arxiv.org/format/2411.11220">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> A new view of the Spiral Structure of the Northern Outer Milky Way in Carbon Monoxide </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sun%2C+Y">Yan Sun</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+J">Ji Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shaobo Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Yan%2C+Q">Qing-Zeng Yan</a>, <a href="/search/astro-ph?searchtype=author&query=Su%2C+Y">Yang Su</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xuepeng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+X">Xin Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+Y">Ye Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H">Hongchi Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+M">Min Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Z">Zhibo Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Sun%2C+J">Ji-Xian Sun</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+D">Deng-Rong Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Ju%2C+B">Bing-Gang Ju</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+X">Xu-Guo Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+M">Min Wang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.11220v1-abstract-short" style="display: inline;"> Based on 32162 molecular clouds from the Milky Way Imaging Scroll Painting project, we obtain new face-on molecular gas maps of the northern outer Galaxy. The total molecular gas surface density map reveals three segments of spirals, extending 16-43 kiloparsecs in length. The Perseus and Outer arms stand out prominently, appearing as quasi-continuous structures along most of their length. At the G… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11220v1-abstract-full').style.display = 'inline'; document.getElementById('2411.11220v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.11220v1-abstract-full" style="display: none;"> Based on 32162 molecular clouds from the Milky Way Imaging Scroll Painting project, we obtain new face-on molecular gas maps of the northern outer Galaxy. The total molecular gas surface density map reveals three segments of spirals, extending 16-43 kiloparsecs in length. The Perseus and Outer arms stand out prominently, appearing as quasi-continuous structures along most of their length. At the Galactic outskirts, about 1306 clouds connect the two segments of the new spiral arm discovered by Dame & Thaddeus (2011) in the first quadrant and Sun et al. (2015) in the second quadrant, possibly extending the arm into the outer third quadrant. Logarithmic spirals can be fitted to the CO arm segments with pitch angles ranging from 4 to 12 degree. These CO arms extend beyond previous CO studies and the optical radius, reaching a galactic radius of about 22 kiloparsecs, comparable to the HI radial range. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11220v1-abstract-full').style.display = 'none'; document.getElementById('2411.11220v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 November, 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">10 pages, 4 figures, 1 table, ApJL accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.10428">arXiv:2411.10428</a> <span> [<a href="https://arxiv.org/pdf/2411.10428">pdf</a>, <a href="https://arxiv.org/format/2411.10428">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> BICEP/Keck XIX: Extremely Thin Composite Polymer Vacuum Windows for BICEP and Other High Throughput Millimeter Wave Telescopes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+B">BICEP/Keck Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Ade%2C+P+A+R">P. A. R. Ade</a>, <a href="/search/astro-ph?searchtype=author&query=Ahmed%2C+Z">Z. Ahmed</a>, <a href="/search/astro-ph?searchtype=author&query=Amiri%2C+M">M. Amiri</a>, <a href="/search/astro-ph?searchtype=author&query=Barkats%2C+D">D. Barkats</a>, <a href="/search/astro-ph?searchtype=author&query=Thakur%2C+R+B">R. Basu Thakur</a>, <a href="/search/astro-ph?searchtype=author&query=Bischoff%2C+C+A">C. A. Bischoff</a>, <a href="/search/astro-ph?searchtype=author&query=Beck%2C+D">D. Beck</a>, <a href="/search/astro-ph?searchtype=author&query=Bock%2C+J+J">J. J. Bock</a>, <a href="/search/astro-ph?searchtype=author&query=Boenish%2C+H">H. Boenish</a>, <a href="/search/astro-ph?searchtype=author&query=Buza%2C+V">V. Buza</a>, <a href="/search/astro-ph?searchtype=author&query=Carter%2C+K">K. Carter</a>, <a href="/search/astro-ph?searchtype=author&query=Cheshire%2C+J+R">J. R. Cheshire IV</a>, <a href="/search/astro-ph?searchtype=author&query=Connors%2C+J">J. Connors</a>, <a href="/search/astro-ph?searchtype=author&query=Cornelison%2C+J">J. Cornelison</a>, <a href="/search/astro-ph?searchtype=author&query=Corrigan%2C+L">L. Corrigan</a>, <a href="/search/astro-ph?searchtype=author&query=Crumrine%2C+M">M. Crumrine</a>, <a href="/search/astro-ph?searchtype=author&query=Crystian%2C+S">S. Crystian</a>, <a href="/search/astro-ph?searchtype=author&query=Cukierman%2C+A+J">A. J. Cukierman</a>, <a href="/search/astro-ph?searchtype=author&query=Denison%2C+E">E. Denison</a>, <a href="/search/astro-ph?searchtype=author&query=Duband%2C+L">L. Duband</a>, <a href="/search/astro-ph?searchtype=author&query=Echter%2C+M">M. Echter</a>, <a href="/search/astro-ph?searchtype=author&query=Eiben%2C+M">M. Eiben</a>, <a href="/search/astro-ph?searchtype=author&query=Elwood%2C+B+D">B. D. Elwood</a> , et al. (69 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="2411.10428v1-abstract-short" style="display: inline;"> Millimeter-wave refracting telescopes targeting the degree-scale structure of the cosmic microwave background (CMB) have recently grown to diffraction-limited apertures of over 0.5 meters. These instruments are entirely housed in vacuum cryostats to support their sub-kelvin bolometric detectors and to minimize radiative loading from thermal emission due to absorption loss in their transmissive opt… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.10428v1-abstract-full').style.display = 'inline'; document.getElementById('2411.10428v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.10428v1-abstract-full" style="display: none;"> Millimeter-wave refracting telescopes targeting the degree-scale structure of the cosmic microwave background (CMB) have recently grown to diffraction-limited apertures of over 0.5 meters. These instruments are entirely housed in vacuum cryostats to support their sub-kelvin bolometric detectors and to minimize radiative loading from thermal emission due to absorption loss in their transmissive optical elements. The large vacuum window is the only optical element in the system at ambient temperature, and therefore minimizing loss in the window is crucial for maximizing detector sensitivity. This motivates the use of low-loss polymer materials and a window as thin as practicable. However, the window must simultaneously meet the requirement to keep sufficient vacuum, and therefore must limit gas permeation and remain mechanically robust against catastrophic failure under pressure. We report on the development of extremely thin composite polyethylene window technology that meets these goals. Two windows have been deployed for two full observing seasons on the BICEP3 and BA150 CMB telescopes at the South Pole. On BICEP3, the window has demonstrated a 6% improvement in detector sensitivity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.10428v1-abstract-full').style.display = 'none'; document.getElementById('2411.10428v1-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 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">20 pages, 12 figures, 4 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.09902">arXiv:2411.09902</a> <span> [<a href="https://arxiv.org/pdf/2411.09902">pdf</a>, <a href="https://arxiv.org/ps/2411.09902">ps</a>, <a href="https://arxiv.org/format/2411.09902">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"> Investigation of the non-thermal X-ray emission from the supernova remnant CTB 37B hosting the magnetar CXOU J171405.7$-$381031 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kim%2C+C">Chanho Kim</a>, <a href="/search/astro-ph?searchtype=author&query=Park%2C+J">Jaegeun Park</a>, <a href="/search/astro-ph?searchtype=author&query=An%2C+H">Hongjun An</a>, <a href="/search/astro-ph?searchtype=author&query=Mori%2C+K">Kaya Mori</a>, <a href="/search/astro-ph?searchtype=author&query=Reynolds%2C+S+P">Stephen P. Reynolds</a>, <a href="/search/astro-ph?searchtype=author&query=Safi-Harb%2C+S">Samar Safi-Harb</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuo Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.09902v1-abstract-short" style="display: inline;"> We present a detailed X-ray investigation of a region (S1) exhibiting non-thermal X-ray emission within the supernova remnant (SNR) CTB 37B hosting the magnetar CXOU J171405.7$-$381031. Previous analyses modeled this emission with a power law (PL), inferring various values for the photon index ($螕$) and absorbing column density ($N_{\rm H}$). Based on these, S1 was suggested to be the SNR shell, a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09902v1-abstract-full').style.display = 'inline'; document.getElementById('2411.09902v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.09902v1-abstract-full" style="display: none;"> We present a detailed X-ray investigation of a region (S1) exhibiting non-thermal X-ray emission within the supernova remnant (SNR) CTB 37B hosting the magnetar CXOU J171405.7$-$381031. Previous analyses modeled this emission with a power law (PL), inferring various values for the photon index ($螕$) and absorbing column density ($N_{\rm H}$). Based on these, S1 was suggested to be the SNR shell, a background pulsar wind nebula (PWN), or an interaction region between the SNR and a molecular cloud. Our analysis of a larger dataset favors a steepening (broken or curved PL) spectrum over a straight PL, with the best-fit broken power-law (BPL) parameters of $螕=1.23\pm0.23$ and $2.24\pm0.16$ below and above a break at $5.57\pm0.52$ keV, respectively. However, a simple PL or srcut model cannot be definitively ruled out. For the BPL model, the inferred $N_{\rm H}=(4.08\pm0.72)\times 10^{22}\rm \ cm^{-2}$ towards S1 is consistent with that of the SNR, suggesting a physical association. The BPL-inferred spectral break $螖螕\approx 1$ and hard $螕$ can be naturally explained by a non-thermal bremsstrahlung (NTB) model. We present an evolutionary NTB model that reproduces the observed spectrum, which indicates the presence of sub-relativistic electrons within S1. However, alternate explanations for S1, an unrelated PWN or the SNR shock with unusually efficient acceleration, cannot be ruled out. We discuss these explanations and their implications for gamma-ray emission from CTB 37B, and describe future observations that could settle the origin of S1. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09902v1-abstract-full').style.display = 'none'; document.getElementById('2411.09902v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 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">11 pages. 4 figures, Accepted for publication in Apj</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.09298">arXiv:2411.09298</a> <span> [<a href="https://arxiv.org/pdf/2411.09298">pdf</a>, <a href="https://arxiv.org/format/2411.09298">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Constraining the Galactic Structure using Time Domain Gravitational Wave Signal from Double White Dwarfs Detected by Space Gravitational Wave Detectors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Siqi Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Deng%2C+F">Furen Deng</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+Y">Youjun Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Yu%2C+S">Shenghua Yu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.09298v1-abstract-short" style="display: inline;"> The Gravitation Wave (GW) signals from a large number of double white dwarfs (DWDs) in the Galaxy are expected to be detected by space GW detectors, e.g., the Laser Interferometer Space Antenna (LISA), Taiji, and Tianqin in the millihertz band. In this paper, we present an alternative method by directly using the time-domain GW signal detected by space GW detectors to constrain the anisotropic str… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09298v1-abstract-full').style.display = 'inline'; document.getElementById('2411.09298v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.09298v1-abstract-full" style="display: none;"> The Gravitation Wave (GW) signals from a large number of double white dwarfs (DWDs) in the Galaxy are expected to be detected by space GW detectors, e.g., the Laser Interferometer Space Antenna (LISA), Taiji, and Tianqin in the millihertz band. In this paper, we present an alternative method by directly using the time-domain GW signal detected by space GW detectors to constrain the anisotropic structure of the Galaxy. The information of anisotropic distribution of DWDs is naturally encoded in the time-domain GW signal because of the variation of the detectors' directions and consequently the pattern functions due to their annual motion around the sun. The direct use of the time-domain GW signal enables simple calculations, such as utilizing an analytical method to assess the noise arising from the superposition of random phases of DWDs and using appropriate weights to improve the constraints. We investigate the possible constraints on the scale of the Galactic thin disk and bulge that may be obtained from LISA and Taiji by using this method with mock signals obtained from population synthesis models. We further show the different constraining capabilities of the low-frequency signal (foreground) and the high-frequency signal (resolvable-sources) via the Markov Chain Monte Carlo method, and find that the scale height and length of the Galactic thin disk and the scale radius of bulge can be constrained to a fractional accuracy of ~ 30%, 30%, 40% (or 20%, 10%, 40%) by using the low-frequency (or high-frequency) signal detected by LISA or Taiji. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09298v1-abstract-full').style.display = 'none'; document.getElementById('2411.09298v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 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">20 pages, 8 figures, accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.03050">arXiv:2411.03050</a> <span> [<a href="https://arxiv.org/pdf/2411.03050">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div 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/10.1117/12.3020020">10.1117/12.3020020 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Wide Field Monitor (WFM) of the China-Europe eXTP (enhanced X-ray Timing and Polarimetry) mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hernanz%2C+M">Margarita Hernanz</a>, <a href="/search/astro-ph?searchtype=author&query=Feroci%2C+M">Marco Feroci</a>, <a href="/search/astro-ph?searchtype=author&query=Evangelista%2C+Y">Yuri Evangelista</a>, <a href="/search/astro-ph?searchtype=author&query=Meuris%2C+A">Aline Meuris</a>, <a href="/search/astro-ph?searchtype=author&query=Schanne%2C+S">St茅phane Schanne</a>, <a href="/search/astro-ph?searchtype=author&query=Zampa%2C+G">Gianluigi Zampa</a>, <a href="/search/astro-ph?searchtype=author&query=Tenzer%2C+C">Chris Tenzer</a>, <a href="/search/astro-ph?searchtype=author&query=Bayer%2C+J">J枚rg Bayer</a>, <a href="/search/astro-ph?searchtype=author&query=Nowosielski%2C+W">Witold Nowosielski</a>, <a href="/search/astro-ph?searchtype=author&query=Michalska%2C+M">Malgorzata Michalska</a>, <a href="/search/astro-ph?searchtype=author&query=Kalemci%2C+E">Emrah Kalemci</a>, <a href="/search/astro-ph?searchtype=author&query=Sungur%2C+M">M眉berra Sungur</a>, <a href="/search/astro-ph?searchtype=author&query=Brandt%2C+S">S酶ren Brandt</a>, <a href="/search/astro-ph?searchtype=author&query=Kuvvetli%2C+I">Irfan Kuvvetli</a>, <a href="/search/astro-ph?searchtype=author&query=Franco%2C+D+A">Daniel Alvarez Franco</a>, <a href="/search/astro-ph?searchtype=author&query=Carmona%2C+A">Alex Carmona</a>, <a href="/search/astro-ph?searchtype=author&query=G%C3%A1lvez%2C+J">Jos茅-Luis G谩lvez</a>, <a href="/search/astro-ph?searchtype=author&query=Patruno%2C+A">Alessandro Patruno</a>, <a href="/search/astro-ph?searchtype=author&query=Zand%2C+J+i+t">Jean in' t Zand</a>, <a href="/search/astro-ph?searchtype=author&query=Zwart%2C+F">Frans Zwart</a>, <a href="/search/astro-ph?searchtype=author&query=Santangelo%2C+A">Andrea Santangelo</a>, <a href="/search/astro-ph?searchtype=author&query=Bozzo%2C+E">Enrico Bozzo</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang-Nan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+F">Fangjun Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+Y">Yupeng Xu</a> , et al. (36 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.03050v1-abstract-short" style="display: inline;"> The eXTP mission is a major project of the Chinese Academy of Sciences (CAS), with a large involvement of Europe. Its scientific payload includes four instruments: SFA, PFA, LAD and WFM. They offer an unprecedented simultaneous wide-band Xray timing and polarimetry sensitivity. A large European consortium is contributing to the eXTP study, both for the science and the instrumentation. Europe is ex… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.03050v1-abstract-full').style.display = 'inline'; document.getElementById('2411.03050v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.03050v1-abstract-full" style="display: none;"> The eXTP mission is a major project of the Chinese Academy of Sciences (CAS), with a large involvement of Europe. Its scientific payload includes four instruments: SFA, PFA, LAD and WFM. They offer an unprecedented simultaneous wide-band Xray timing and polarimetry sensitivity. A large European consortium is contributing to the eXTP study, both for the science and the instrumentation. Europe is expected to provide two of the four instruments: LAD and WFM; the LAD is led by Italy and the WFM by Spain. The WFM for eXTP is based on the design originally proposed for the LOFT ESA M3 mission, that underwent a Phase A feasibility study. It will be a wide field of view X-ray monitor instrument working in the 2-50 keV energy range, achieved with large-area Silicon Drift Detectors (SDDs), similar to the ones used for the LAD but with better spatial resolution. The WFM will consist of 3 pairs of coded mask cameras with a total combined field of view (FoV) of 90x180 degrees at zero response and a source localisation accuracy of ~1 arc min. The main goal of the WFM is to provide triggers for the target of opportunity observations of the SFA, PFA and LAD, in order to perform the core science programme, dedicated to the study of matter under extreme conditions of density, gravity and magnetism. In addition, the unprecedented combination of large field of view and imaging capability, down to 2 keV, of the WFM will allow eXTP to make important discoveries of the variable and transient X-ray sky, and provide X-ray coverage of a broad range of astrophysical objects covered under 'observatory science', such as gamma-ray bursts, fast radio bursts, gravitational wave electromagnetic counterparts. In this paper we provide an overview of the WFM instrument, explaining its design, configuration, and anticipated performance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.03050v1-abstract-full').style.display = 'none'; document.getElementById('2411.03050v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 November, 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">15 pages, 13 figures, Proceedings of SPIE 13093, Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray; Proceedings Volume 13093, Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray; 130931Y (2024); doi: 10.1117/12.3020020</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Proc. of SPIE 2024 Vol. 13093 130931Y </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.01215">arXiv:2411.01215</a> <span> [<a href="https://arxiv.org/pdf/2411.01215">pdf</a>, <a href="https://arxiv.org/format/2411.01215">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"> Detection of two TeV gamma-ray outbursts from NGC 1275 by LHAASO </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Zhen Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=Axikegu"> Axikegu</a>, <a href="/search/astro-ph?searchtype=author&query=Bai%2C+Y+X">Y. X. Bai</a>, <a href="/search/astro-ph?searchtype=author&query=Bao%2C+Y+W">Y. W. Bao</a>, <a href="/search/astro-ph?searchtype=author&query=Bastieri%2C+D">D. Bastieri</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+Y+J">Y. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+J+T">J. T. Cai</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Q">Q. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+W+Y">W. Y. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Zhe Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Chang%2C+J">J. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chang%2C+J+F">J. F. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+A+M">A. M. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+E+S">E. S. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Liang Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Lin Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Long Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+M+J">M. J. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+M+L">M. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Q+H">Q. H. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S+H">S. H. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S+Z">S. Z. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a> , et al. (254 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="2411.01215v2-abstract-short" style="display: inline;"> The Water Cherenkov Detector Array (WCDA) is one of the components of Large High Altitude Air Shower Observatory (LHAASO) and can monitor any sources over two-thirds of the sky for up to 7 hours per day with >98\% duty cycle. In this work, we report the detection of two outbursts of the Fanaroff-Riley I radio galaxy NGC 1275 that were detected by LHAASO-WCDA between November 2022 and January 2023… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.01215v2-abstract-full').style.display = 'inline'; document.getElementById('2411.01215v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.01215v2-abstract-full" style="display: none;"> The Water Cherenkov Detector Array (WCDA) is one of the components of Large High Altitude Air Shower Observatory (LHAASO) and can monitor any sources over two-thirds of the sky for up to 7 hours per day with >98\% duty cycle. In this work, we report the detection of two outbursts of the Fanaroff-Riley I radio galaxy NGC 1275 that were detected by LHAASO-WCDA between November 2022 and January 2023 with statistical significance of 5.2~$蟽$ and 8.3~$蟽$. The observed spectral energy distribution in the range from 500 GeV to 3 TeV is fitted by a power-law with a best-fit spectral index of $伪=-3.37\pm0.52$ and $-3.35\pm0.29$, respectively. The outburst flux above 0.5~TeV was ($4.55\pm 4.21)\times~10^{-11}~\rm cm^{-2}~s^{-1}$ and ($3.45\pm 1.78)\times~10^{-11}~\rm cm^{-2}~s^{-1}$, corresponding to 60\%, 45\% of Crab Nebula flux. Variation analysis reveals the variability time-scale of days at the TeV energy band. A simple test by one-zone synchrotron self-Compton model reproduces the data in the gamma-ray band well. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.01215v2-abstract-full').style.display = 'none'; document.getElementById('2411.01215v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 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">11 pages, 8 figures, 3 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.21617">arXiv:2410.21617</a> <span> [<a href="https://arxiv.org/pdf/2410.21617">pdf</a>, <a href="https://arxiv.org/format/2410.21617">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/10.1007/s11433-024-2524-4">10.1007/s11433-024-2524-4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Einstein Probe discovery of EP240408a: a peculiar X-ray transient with an intermediate timescale </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+W">Wenda Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Yuan%2C+W">Weimin Yuan</a>, <a href="/search/astro-ph?searchtype=author&query=Ling%2C+Z">Zhixing Ling</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yong Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Rea%2C+N">Nanda Rea</a>, <a href="/search/astro-ph?searchtype=author&query=Rau%2C+A">Arne Rau</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+Z">Zhiming Cai</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+H">Huaqing Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Zelati%2C+F+C">Francesco Coti Zelati</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+L">Lixin Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+J">Jingwei Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+S">Shumei Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Jin%2C+C">Chichuan Jin</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+D">Dongyue Li</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">Paul O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Shen%2C+R">Rongfeng Shen</a>, <a href="/search/astro-ph?searchtype=author&query=Shu%2C+X">Xinwen Shu</a>, <a href="/search/astro-ph?searchtype=author&query=Sun%2C+S">Shengli Sun</a>, <a href="/search/astro-ph?searchtype=author&query=Sun%2C+X">Xiaojin Sun</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+X">Xiaofeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+L">Lei Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+B">Bing Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+C">Chen Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang-Nan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y">Yonghe Zhang</a> , et al. (115 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="2410.21617v1-abstract-short" style="display: inline;"> We report the discovery of a peculiar X-ray transient, EP240408a, by Einstein Probe (EP) and follow-up studies made with EP, Swift, NICER, GROND, ATCA and other ground-based multi-wavelength telescopes. The new transient was first detected with Wide-field X-ray Telescope (WXT) on board EP on April 8th, 2024, manifested in an intense yet brief X-ray flare lasting for 12 seconds. The flare reached a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.21617v1-abstract-full').style.display = 'inline'; document.getElementById('2410.21617v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.21617v1-abstract-full" style="display: none;"> We report the discovery of a peculiar X-ray transient, EP240408a, by Einstein Probe (EP) and follow-up studies made with EP, Swift, NICER, GROND, ATCA and other ground-based multi-wavelength telescopes. The new transient was first detected with Wide-field X-ray Telescope (WXT) on board EP on April 8th, 2024, manifested in an intense yet brief X-ray flare lasting for 12 seconds. The flare reached a peak flux of 3.9x10^(-9) erg/cm2/s in 0.5-4 keV, about 300 times brighter than the underlying X-ray emission detected throughout the observation. Rapid and more precise follow-up observations by EP/FXT, Swift and NICER confirmed the finding of this new transient. Its X-ray spectrum is non-thermal in 0.5-10 keV, with a power-law photon index varying within 1.8-2.5. The X-ray light curve shows a plateau lasting for about 4 days, followed by a steep decay till becoming undetectable about 10 days after the initial detection. Based on its temporal property and constraints from previous EP observations, an unusual timescale in the range of 7-23 days is found for EP240408a, which is intermediate between the commonly found fast and long-term transients. No counterparts have been found in optical and near-infrared, with the earliest observation at 17 hours after the initial X-ray detection, suggestive of intrinsically weak emission in these bands. We demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far, by comparison with, in particular, jetted tidal disruption events, gamma-ray bursts, X-ray binaries and fast blue optical transients. The nature of EP240408a thus remains an enigma. We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of about 10 days. The detection and follow-ups of more of such objects are essential for revealing their origin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.21617v1-abstract-full').style.display = 'none'; document.getElementById('2410.21617v1-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">25 pages, 11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> published in SCIENCE CHINA Physics, Mechanics & Astronomy(SCPMA) (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.20025">arXiv:2410.20025</a> <span> [<a href="https://arxiv.org/pdf/2410.20025">pdf</a>, <a href="https://arxiv.org/format/2410.20025">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Cross-Survey Image Transformation: Enhancing SDSS and DECaLS Images to Near-HSC Quality for Advanced Astronomical Analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Luo%2C+Z">Zhijian Luo</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shaohua Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">Jianzhen Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z">Zhu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Fu%2C+L">Liping Fu</a>, <a href="/search/astro-ph?searchtype=author&query=Xiao%2C+H">Hubing Xiao</a>, <a href="/search/astro-ph?searchtype=author&query=Du%2C+W">Wei Du</a>, <a href="/search/astro-ph?searchtype=author&query=Shu%2C+C">Chenggang Shu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.20025v1-abstract-short" style="display: inline;"> This study focuses on transforming galaxy images between astronomical surveys, specifically enhancing images from the Sloan Digital Sky Survey (SDSS) and the Dark Energy Camera Legacy Survey (DECaLS) to achieve quality comparable to the Hyper Suprime-Cam survey (HSC). We proposed a hybrid model called Pix2WGAN, which integrates the pix2pix framework with the Wasserstein Generative Adversarial Netw… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.20025v1-abstract-full').style.display = 'inline'; document.getElementById('2410.20025v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.20025v1-abstract-full" style="display: none;"> This study focuses on transforming galaxy images between astronomical surveys, specifically enhancing images from the Sloan Digital Sky Survey (SDSS) and the Dark Energy Camera Legacy Survey (DECaLS) to achieve quality comparable to the Hyper Suprime-Cam survey (HSC). We proposed a hybrid model called Pix2WGAN, which integrates the pix2pix framework with the Wasserstein Generative Adversarial Network with Gradient Penalty (WGAN-GP) to convert low-quality observational images into high-quality counterparts. Our model successfully transformed DECaLS images into pseudo-HSC images, yielding impressive results and significantly enhancing the identification of complex structures, such as galaxy spiral arms and tidal tails, which may have been overlooked in the original DECaLS images. Moreover, Pix2WGAN effectively addresses issues like artifacts, noise, and blurriness in both source and target images. In addition to the basic Pix2WGAN model, we further developed an advanced architecture called Cascaded Pix2WGAN, which incorporates a multi-stage training mechanism designed to bridge the quality gap between SDSS and HSC images, demonstrating similarly promising outcomes. We systematically assessed the similarity between the model-generated pseudo-HSC images and actual HSC images using various metrics, including Mean Squared Error (MSE), Peak Signal-to-Noise Ratio (PSNR), and Structural Similarity Index (SSIM), along with perceptual metrics such as Learned Perceptual Image Patch Similarity (LPIPS) and Fr茅chet Inception Distance (FID). The results indicate that images transformed by our model outperform both the original SDSS and DECaLS images across nearly all evaluation metrics. Our research is expected to provide significant technical support for astronomical data analysis, cross-survey image integration, and high-precision astrometry. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.20025v1-abstract-full').style.display = 'none'; document.getElementById('2410.20025v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.19402">arXiv:2410.19402</a> <span> [<a href="https://arxiv.org/pdf/2410.19402">pdf</a>, <a href="https://arxiv.org/format/2410.19402">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Photometric Redshift Estimation for CSST Survey with LSTM Neural Networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Luo%2C+Z">Zhijian Luo</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Y">Yicheng Li</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+J">Junhao Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z">Zhu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Fu%2C+L">Liping Fu</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shaohua Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Xiao%2C+H">Hubing Xiao</a>, <a href="/search/astro-ph?searchtype=author&query=Du%2C+W">Wei Du</a>, <a href="/search/astro-ph?searchtype=author&query=Gong%2C+Y">Yan Gong</a>, <a href="/search/astro-ph?searchtype=author&query=Shu%2C+C">Chenggang Shu</a>, <a href="/search/astro-ph?searchtype=author&query=Ma%2C+W">Wenwen Ma</a>, <a href="/search/astro-ph?searchtype=author&query=Meng%2C+X">Xianmin Meng</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+X">Xingchen Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Fan%2C+Z">Zuhui Fan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.19402v1-abstract-short" style="display: inline;"> Accurate estimation of photometric redshifts (photo-$z$s) is crucial for cosmological surveys. Various methods have been developed for this purpose, such as template fitting methods and machine learning techniques, each with its own applications, advantages, and limitations. In this study, we propose a new approach that utilizes a deep learning model based on Recurrent Neural Networks (RNN) with L… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.19402v1-abstract-full').style.display = 'inline'; document.getElementById('2410.19402v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.19402v1-abstract-full" style="display: none;"> Accurate estimation of photometric redshifts (photo-$z$s) is crucial for cosmological surveys. Various methods have been developed for this purpose, such as template fitting methods and machine learning techniques, each with its own applications, advantages, and limitations. In this study, we propose a new approach that utilizes a deep learning model based on Recurrent Neural Networks (RNN) with Long Short-Term Memory (LSTM) to predict photo-$z$. Unlike many existing machine learning models, our method requires only flux measurements from different observed filters as input. The model can automatically learn the complex relationships between the flux data across different wavelengths, eliminating the need for manually extracted or derived input features, thereby providing precise photo-$z$ estimates. The effectiveness of our proposed model is evaluated using simulated data from the Chinese Space Station Telescope (CSST) sourced from the Hubble Space Telescope Advanced Camera for Surveys (HST-ACS) and the COSMOS catalog, considering anticipated instrument effects of the future CSST. Results from experiments demonstrate that our LSTM model, compared to commonly used template fitting and machine learning approaches, requires minimal input parameters and achieves high precision in photo-$z$ estimation. For instance, when trained on the same dataset and provided only with photometric fluxes as input features, the proposed LSTM model yields one-third of the outliers $f_{out}$ observed with a Multi-Layer Perceptron Neural Network (MLP) model, while the normalized median absolute deviation $\rm 蟽_{NMAD}$ is only two-thirds that of the MLP model. This study presents a novel approach to accurately estimate photo-$z$s of galaxies using photometric data from large-scale survey projects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.19402v1-abstract-full').style.display = 'none'; document.getElementById('2410.19402v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.18562">arXiv:2410.18562</a> <span> [<a href="https://arxiv.org/pdf/2410.18562">pdf</a>, <a href="https://arxiv.org/format/2410.18562">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Prediction of Large Solar Flares Based on SHARP and HED Magnetic Field Parameters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Li%2C+X">Xuebao Li</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+X">Xuefeng Li</a>, <a href="/search/astro-ph?searchtype=author&query=Zheng%2C+Y">Yanfang Zheng</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+T">Ting Li</a>, <a href="/search/astro-ph?searchtype=author&query=Yan%2C+P">Pengchao Yan</a>, <a href="/search/astro-ph?searchtype=author&query=Ye%2C+H">Hongwei Ye</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shunhuang Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+X">Xiaotian Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Lv%2C+Y">Yongshang Lv</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">Xusheng Huang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.18562v1-abstract-short" style="display: inline;"> The existing flare prediction primarily relies on photospheric magnetic field parameters from the entire active region (AR), such as Space-Weather HMI Activity Region Patches (SHARP) parameters. However, these parameters may not capture the details the AR evolution preceding flares. The magnetic structure within the core area of an AR is essential for predicting large solar flares. This paper util… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.18562v1-abstract-full').style.display = 'inline'; document.getElementById('2410.18562v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.18562v1-abstract-full" style="display: none;"> The existing flare prediction primarily relies on photospheric magnetic field parameters from the entire active region (AR), such as Space-Weather HMI Activity Region Patches (SHARP) parameters. However, these parameters may not capture the details the AR evolution preceding flares. The magnetic structure within the core area of an AR is essential for predicting large solar flares. This paper utilizes the area of high photospheric free energy density (HED region) as a proxy for the AR core region. We construct two datasets: SHARP and HED datasets. The ARs contained in both datasets are identical. Furthermore, the start and end times for the same AR in both datasets are identical. We develop six models for 24-hour solar flare forecasting, utilizing SHARP and HED datasets. We then compare their categorical and probabilistic forecasting performance. Additionally, we conduct an analysis of parameter importance. The main results are as follows: (1) Among the six solar flare prediction models, the models using HED parameters outperform those using SHARP parameters in both categorical and probabilistic prediction, indicating the important role of the HED region in the flare initiation process. (2) The Transformer flare prediction model stands out significantly in True Skill Statistic (TSS) and Brier Skill Score (BSS), surpassing the other models. (3) In parameter importance analysis, the total photospheric free magnetic energy density ($\mathrm {E_{free}}$) within the HED parameters excels in both categorical and probabilistic forecasting. Similarly, among the SHARP parameters, the R_VALUE stands out as the most effective parameter for both categorical and probabilistic forecasting. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.18562v1-abstract-full').style.display = 'none'; document.getElementById('2410.18562v1-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.17833">arXiv:2410.17833</a> <span> [<a href="https://arxiv.org/pdf/2410.17833">pdf</a>, <a href="https://arxiv.org/ps/2410.17833">ps</a>, <a href="https://arxiv.org/format/2410.17833">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> </div> <p class="title is-5 mathjax"> Ground calibration and network of the first CATCH pathfinder </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y">Yiming Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Xiao%2C+J">Jingyu Xiao</a>, <a href="/search/astro-ph?searchtype=author&query=Tao%2C+L">Lian Tao</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shuang-Nan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Yin%2C+Q">Qian-Qing Yin</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Y">Yusa Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+Z">Zijian Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+C">Chen Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+Q">Qingchang Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Ma%2C+X">Xiang Ma</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+S">Shujie Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+H">Heng Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Wen%2C+X">Xiangyang Wen</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhengwei Li</a>, <a href="/search/astro-ph?searchtype=author&query=Xiong%2C+S">Shaolin Xiong</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">Juan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Bu%2C+Q">Qingcui Bu</a>, <a href="/search/astro-ph?searchtype=author&query=Cang%2C+J">Jirong Cang</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+D">Dezhi Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W">Wen Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+S">Siran Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+Y">Yanfeng Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+M">Min Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Y">Yang Gao</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H">Huilin He</a> , et al. (31 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="2410.17833v1-abstract-short" style="display: inline;"> The Chasing All Transients Constellation Hunters (CATCH) space mission is focused on exploring the dynamic universe via X-ray follow-up observations of various transients. The first pathfinder of the CATCH mission, CATCH-1, was launched on June 22, 2024, alongside the Space-based multiband astronomical Variable Objects Monitor (SVOM) mission. CATCH-1 is equipped with narrow-field optimized Micro P… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17833v1-abstract-full').style.display = 'inline'; document.getElementById('2410.17833v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.17833v1-abstract-full" style="display: none;"> The Chasing All Transients Constellation Hunters (CATCH) space mission is focused on exploring the dynamic universe via X-ray follow-up observations of various transients. The first pathfinder of the CATCH mission, CATCH-1, was launched on June 22, 2024, alongside the Space-based multiband astronomical Variable Objects Monitor (SVOM) mission. CATCH-1 is equipped with narrow-field optimized Micro Pore Optics (MPOs) featuring a large effective area and incorporates four Silicon Drift Detectors (SDDs) in its focal plane. This paper presents the system calibration results conducted before the satellite integration. Utilizing the data on the performance of the mirror and detectors obtained through the system calibration, combined with simulated data, the ground calibration database can be established. Measuring the relative positions of the mirror and detector system, which were adjusted during system calibration, allows for accurate installation of the entire satellite. Furthermore, the paper outlines the operational workflow of the ground network post-satellite launch. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17833v1-abstract-full').style.display = 'none'; document.getElementById('2410.17833v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.17455">arXiv:2410.17455</a> <span> [<a href="https://arxiv.org/pdf/2410.17455">pdf</a>, <a href="https://arxiv.org/format/2410.17455">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> ATOMS: ALMA three-millimeter observations of massive star-forming regions -- XVIII. On the origin and evolution of dense gas fragments in molecular shells of compact HII regions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Siju Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+T">Tie Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zavagno%2C+A">Annie Zavagno</a>, <a href="/search/astro-ph?searchtype=author&query=Garay%2C+G">Guido Garay</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+H">Hongli Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+F">Fengwei Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+X">Xunchuan Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Sanhueza%2C+P">Patricio Sanhueza</a>, <a href="/search/astro-ph?searchtype=author&query=Soam%2C+A">Archana Soam</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+J">Jian-wen Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+S">Shanghuo Li</a>, <a href="/search/astro-ph?searchtype=author&query=Goldsmith%2C+P+F">Paul F. Goldsmith</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y">Yong Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Chibueze%2C+J+O">James O. Chibueze</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+C+W">Chang Won Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Hwang%2C+J">Jihye Hwang</a>, <a href="/search/astro-ph?searchtype=author&query=Bronfman%2C+L">Leonardo Bronfman</a>, <a href="/search/astro-ph?searchtype=author&query=Dewangan%2C+L+K">Lokesh K. Dewangan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.17455v1-abstract-short" style="display: inline;"> Fragmentation and evolution for the molecular shells of the compact HII regions are less explored compared to their evolved counterparts. We map nine compact HII regions with a typical diameter of 0.4 pc that are surrounded by molecular shells traced by CCH. Several to a dozen dense gas fragments probed by H13CO+ are embedded in these molecular shells. These gas fragments, strongly affected by the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17455v1-abstract-full').style.display = 'inline'; document.getElementById('2410.17455v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.17455v1-abstract-full" style="display: none;"> Fragmentation and evolution for the molecular shells of the compact HII regions are less explored compared to their evolved counterparts. We map nine compact HII regions with a typical diameter of 0.4 pc that are surrounded by molecular shells traced by CCH. Several to a dozen dense gas fragments probed by H13CO+ are embedded in these molecular shells. These gas fragments, strongly affected by the HII region, have a higher surface density, mass, and turbulence than those outside the shells but within the same pc-scale natal clump. These features suggest that the shells swept up by the early HII regions can enhance the formation of massive dense structures that may host the birth of higher-mass stars. We examine the formation of fragments and find that fragmentation of the swept-up shell is unlikely to occur in these early HII regions, by comparing the expected time scale of shell fragmentation with the age of HII region. We propose that the appearance of gas fragments in these shells is probably the result of sweeping up pre-existing fragments into the molecular shell that has not yet fragmented. Taken together, this work provides a basis for understanding the interplay of star-forming sites with an intricate environment containing ionization feedback such as those observed in starburst regions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17455v1-abstract-full').style.display = 'none'; document.getElementById('2410.17455v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by MNRAS, 24 pages, 14 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/2410.17189">arXiv:2410.17189</a> <span> [<a href="https://arxiv.org/pdf/2410.17189">pdf</a>, <a href="https://arxiv.org/format/2410.17189">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"> Temporal and Spectral Analysis of the Unique and Second Brightest Gamma-Ray Burst GRB 230307A: Insights from GECAM and Fermi/GBM Observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Moradi%2C+R">R. Moradi</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+C+W">C. W. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+B">B. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Y">Y. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Xiong%2C+S+-">S. -L. Xiong</a>, <a href="/search/astro-ph?searchtype=author&query=Yi%2C+S+-">S. -X. Yi</a>, <a href="/search/astro-ph?searchtype=author&query=Tan%2C+W+-">W. -J. Tan</a>, <a href="/search/astro-ph?searchtype=author&query=Karlica%2C+M">M. Karlica</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S+-">S. -N. Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.17189v1-abstract-short" style="display: inline;"> In this study, we present the pulse profile of the unique and the second brightest gamma-ray burst GRB 230307A, and analyze its temporal behavior using a joint GECAM--Fermi/GBM time-resolved spectral analysis. The utilization of GECAM data is advantageous as it successfully captured significant data during the pile-up period of the Fermi/GBM. We investigate the evolution of its flux, photon fluenc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17189v1-abstract-full').style.display = 'inline'; document.getElementById('2410.17189v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.17189v1-abstract-full" style="display: none;"> In this study, we present the pulse profile of the unique and the second brightest gamma-ray burst GRB 230307A, and analyze its temporal behavior using a joint GECAM--Fermi/GBM time-resolved spectral analysis. The utilization of GECAM data is advantageous as it successfully captured significant data during the pile-up period of the Fermi/GBM. We investigate the evolution of its flux, photon fluence, photon flux, peak energy, and the corresponding hardness-intensity and hardness-flux correlations. The findings within the first 27 seconds exhibit consistent patterns reported previously, providing valuable insights for comparing observations with predictions from the synchrotron radiation model invoking an expanding shell. Beyond the initial 27 seconds, we observe a notable transition in the emitted radiation, attributed to high latitude emission (HLE), influenced by the geometric properties of the shells and the relativistic Doppler effects. By modeling the data within the framework of the large-radius internal shock model, we discuss the required parameters as well as the limitations of the model. We conclude that a more complicated synchrotron emission model is needed to fully describe the observational data of GRB 230307A. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.17189v1-abstract-full').style.display = 'none'; document.getElementById('2410.17189v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in The Astrophysical Journal (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/2410.16086">arXiv:2410.16086</a> <span> [<a href="https://arxiv.org/pdf/2410.16086">pdf</a>, <a href="https://arxiv.org/format/2410.16086">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Nuclear Experiment">nucl-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Enhanced $S$-factor for the $^{14}$N$(p,纬)^{15}$O reaction and its impact on the solar composition problem </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">X. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Su%2C+J">J. Su</a>, <a href="/search/astro-ph?searchtype=author&query=Shen%2C+Y+P">Y. P. Shen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+L+Y">L. Y. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+J+J">J. J. He</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S+Z">S. Z. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+S">S. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Shen%2C+Z+L">Z. L. Shen</a>, <a href="/search/astro-ph?searchtype=author&query=Lin%2C+S">S. Lin</a>, <a href="/search/astro-ph?searchtype=author&query=Song%2C+L+Y">L. Y. Song</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+H">H. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L+H">L. H. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+X+Z">X. Z. Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+L">L. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y+T">Y. T. Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Qin%2C+Z+W">Z. W. Qin</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+F+C">F. C. Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Sheng%2C+Y+D">Y. D. Sheng</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y+J">Y. J. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Lu%2C+Y+L">Y. L. Lu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+X+Y">X. Y. Li</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+J+Y">J. Y. Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Y+C">Y. C. Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y+Q">Y. Q. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y">Y. Zhang</a> , et al. (23 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="2410.16086v1-abstract-short" style="display: inline;"> The solar composition problem has puzzled astrophysicists for more than 20 years. Recent measurements of carbon-nitrogen-oxygen (CNO) neutrinos by the Borexino experiment show a $\sim2蟽$ tension with the "low-metallicity" determinations. $^{14}$N$(p,纬)^{15}$O, the slowest reaction in the CNO cycle, plays a crucial role in the standard solar model (SSM) calculations of CNO neutrino fluxes. Here we… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.16086v1-abstract-full').style.display = 'inline'; document.getElementById('2410.16086v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.16086v1-abstract-full" style="display: none;"> The solar composition problem has puzzled astrophysicists for more than 20 years. Recent measurements of carbon-nitrogen-oxygen (CNO) neutrinos by the Borexino experiment show a $\sim2蟽$ tension with the "low-metallicity" determinations. $^{14}$N$(p,纬)^{15}$O, the slowest reaction in the CNO cycle, plays a crucial role in the standard solar model (SSM) calculations of CNO neutrino fluxes. Here we report a direct measurement of the $^{14}$N$(p,纬)^{15}$O reaction, in which $S$-factors for all transitions were simultaneously determined in the energy range of $E_p=110-260$ keV for the first time. Our results resolve previous discrepancies in the ground-state transition, yielding a zero-energy $S$-factor $S_{114}(0) = 1.92\pm0.08$ keV b which is 14% higher than the $1.68\pm0.14$ keV b recommended in Solar Fusion III (SF-III). With our $S_{114}$ values, the SSM B23-GS98, and the latest global analysis of solar neutrino measurements, the C and N photospheric abundance determined by the Borexino experiment is updated to $N_{\mathrm{CN}}=({4.45}^{+0.69}_{-0.61})\times10^{-4}$. This new $N_{\mathrm{CN}}$ value agrees well with latest "high-metallicity" composition, however, is also consistent with the "low-metallicity" determination within $\sim 1蟽$ C.L., indicating that the solar metallicity problem remains an open question. In addition, the significant reduction in the uncertainty of $S_{114}$ paves the way for the precise determination of the CN abundance in future large-volume solar neutrino measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.16086v1-abstract-full').style.display = 'none'; document.getElementById('2410.16086v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.15333">arXiv:2410.15333</a> <span> [<a href="https://arxiv.org/pdf/2410.15333">pdf</a>, <a href="https://arxiv.org/format/2410.15333">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> The ALMA-QUARKS Survey: Fibers' role in star formation unveiled in an intermediate-mass protocluster region of the Vela D cloud </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yang%2C+D">Dongting Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+H">HongLi Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+T">Tie Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Tej%2C+A">Anandmayee Tej</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+X">Xunchuan Liu</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+J">Jinhua He</a>, <a href="/search/astro-ph?searchtype=author&query=Garay%2C+G">Guido Garay</a>, <a href="/search/astro-ph?searchtype=author&query=Stutz%2C+A">Amelia Stutz</a>, <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+L">Lei Zhu</a>, <a href="/search/astro-ph?searchtype=author&query=Qin%2C+S">Sheng-Li Qin</a>, <a href="/search/astro-ph?searchtype=author&query=Xu%2C+F">Fengwei Xu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+P">Pak-Shing Li</a>, <a href="/search/astro-ph?searchtype=author&query=Juvela%2C+M">Mika Juvela</a>, <a href="/search/astro-ph?searchtype=author&query=Garcia%2C+P">Pablo Garcia</a>, <a href="/search/astro-ph?searchtype=author&query=Goldsmith%2C+P+F">Paul F. Goldsmith</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Siju Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Tang%2C+X">Xindi Tang</a>, <a href="/search/astro-ph?searchtype=author&query=Sanhueza%2C+P">Patricio Sanhueza</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+S">Shanghuo Li</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+C+W">Chang Won Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Das%2C+S+R">Swagat Ranjan Das</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+W">Wenyu Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Mai%2C+X">Xiaofeng Mai</a>, <a href="/search/astro-ph?searchtype=author&query=Gorai%2C+P">Prasanta Gorai</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Y">Yichen Zhang</a> , et al. (10 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.15333v2-abstract-short" style="display: inline;"> In this paper, we present a detailed analysis of the IRS 17 filament within the intermediate-mass protocluster IRAS 08448-4343 (of $\sim\,10^3\,\rm L_{\odot}$), using ALMA data from the ATOMS 3-mm and QUARKS 1.3-mm surveys. The IRS 17 filament, which spans $\sim$54000 au ($0.26\,\rm pc$) in length and $\sim$4000 au ($0.02\,\rm pc$) in width, exhibits a complex, multi-component velocity field, and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15333v2-abstract-full').style.display = 'inline'; document.getElementById('2410.15333v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.15333v2-abstract-full" style="display: none;"> In this paper, we present a detailed analysis of the IRS 17 filament within the intermediate-mass protocluster IRAS 08448-4343 (of $\sim\,10^3\,\rm L_{\odot}$), using ALMA data from the ATOMS 3-mm and QUARKS 1.3-mm surveys. The IRS 17 filament, which spans $\sim$54000 au ($0.26\,\rm pc$) in length and $\sim$4000 au ($0.02\,\rm pc$) in width, exhibits a complex, multi-component velocity field, and harbours hierarchical substructures. These substructures include three bundles of seven velocity-coherent fibers, and 29 dense ($n\sim 10^8\,\rm cm^{-3}$) condensations. The fibers have a median length of $\sim 4500\,\rm au$ and a median width of $\sim 1400\,\rm au$. Among these fibers, four are identified as ``fertile", each hosting at least three dense condensations, which are regarded as the ``seeds" of star formation. While the detected cores are randomly spaced within the IRS\,17 filament based on the 3-mm dust continuum image, periodic spacing ($\sim1600\,\rm au$) of condensations is observed in the fertile fibers according to the 1.3-mm dust map, consistent with the predictions of linear isothermal cylinder fragmentation models. These findings underscore the crucial role of fibers in star formation and suggest a hierarchical fragmentation process that extends from the filament to the fibers, and ultimately, to the smallest-scale condensations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15333v2-abstract-full').style.display = 'none'; document.getElementById('2410.15333v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 10 figures, 4 tables, 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/2410.15039">arXiv:2410.15039</a> <span> [<a href="https://arxiv.org/pdf/2410.15039">pdf</a>, <a href="https://arxiv.org/format/2410.15039">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Double-edged sword: the influence of tidal interaction on stellar activity in binaries </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ding%2C+Y">Yuedan Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shidi Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Han%2C+H">Henggeng Han</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+W">Wenyuan Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+S">Song Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+M">Min Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Y">Yawei Gao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.15039v1-abstract-short" style="display: inline;"> Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed a binary sample and a single-star sample, mainly using the binary belt and the main sequence in the Hertzsprung-Russell diagram, respectively. By comparing the $S$ indices between single and binary stars within each color bin, we found for… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15039v1-abstract-full').style.display = 'inline'; document.getElementById('2410.15039v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.15039v1-abstract-full" style="display: none;"> Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed a binary sample and a single-star sample, mainly using the binary belt and the main sequence in the Hertzsprung-Russell diagram, respectively. By comparing the $S$ indices between single and binary stars within each color bin, we found for K type stars, binaries exhibit enhanced activity compared to single stars, which could be attributed to the increase in spin rate caused by tidal synchronization or to the interactions of magnetic fields. Both single stars and binaries fall on a common sequence in the activity-period relation, indicating that chromospheric activities of binaries are dominated by the more active components. More intriguingly, in some color ranges, a slight decline of the $S$ index for smaller orbital period was observed for binary stars. Although the possibility of sample selection effects cannot be excluded, this may mark the first example of super-saturation (i.e., caused by reduced active regions) being detected in chromospheric activity, or provide evidence of the suppressing effect on the magnetic dynamo and stellar activities by strong tidal interaction in very close binaries. Our study suggests that tidal interaction acts as a double-edged sword in relation to stellar activities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15039v1-abstract-full').style.display = 'none'; document.getElementById('2410.15039v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages,7 figures. Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.15034">arXiv:2410.15034</a> <span> [<a href="https://arxiv.org/pdf/2410.15034">pdf</a>, <a href="https://arxiv.org/format/2410.15034">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Revisiting the Velocity Dispersion-Size Relation in Molecular Cloud Structures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Feng%2C+H">Haoran Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Z">Zhiwei Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Jiang%2C+Z">Zhibo Jiang</a>, <a href="/search/astro-ph?searchtype=author&query=Ma%2C+Y">Yuehui Ma</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yang Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Yu%2C+S">Shuling Yu</a>, <a href="/search/astro-ph?searchtype=author&query=Ge%2C+D">Dongqing Ge</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+W">Wei Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Du%2C+F">Fujun Du</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+C">Chen Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shiyu Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Su%2C+Y">Yang Su</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+J">Ji Yang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.15034v1-abstract-short" style="display: inline;"> Structures in molecular ISM are observed to follow a power-law relation between the velocity dispersion and spatial size, known as Larson's first relation, which is often attributed to the turbulent nature of molecular ISM and imprints the dynamics of molecular cloud structures. Using the ${}^{13}\mathrm{CO}~(J=1-0)$ data from the Milky Way Imaging Scroll Painting survey, we built a sample with 36… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15034v1-abstract-full').style.display = 'inline'; document.getElementById('2410.15034v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.15034v1-abstract-full" style="display: none;"> Structures in molecular ISM are observed to follow a power-law relation between the velocity dispersion and spatial size, known as Larson's first relation, which is often attributed to the turbulent nature of molecular ISM and imprints the dynamics of molecular cloud structures. Using the ${}^{13}\mathrm{CO}~(J=1-0)$ data from the Milky Way Imaging Scroll Painting survey, we built a sample with 360 structures having relatively accurate distances obtained from either the reddened background stars with Gaia parallaxes or associated maser parallaxes, spanning from $0.4$ to $\sim 15~\mathrm{kpc}$. Using this sample and about 0.3 million pixels, we analyzed the correlations between velocity dispersion, surface/column density, and spatial scales. Our structure-wise results show power-law indices smaller than 0.5 in both the $蟽_v$-$R_{\mathrm{eff}}$ and $蟽_v$-$R_{\mathrm{eff}} \cdot 危$ relations. In the pixel-wise results, the $蟽_v^{\mathrm{pix}}$ is statistically scaling with the beam physical size ($R_{\mathrm{s}} \equiv 螛D/2$) in form of $蟽_v^{\mathrm{pix}} \propto R_{\mathrm{s}}^{0.43 \pm 0.03}$. Meanwhile, $蟽_v^{\mathrm{pix}}$ in the inner Galaxy is statistically larger than the outer side. We also analyzed correlations between $蟽_v^{\mathrm{pix}}$ and the $\mathrm{H_2}$ column density $N(\mathrm{H_2})$, finding that $蟽_v^{\mathrm{pix}}$ stops increasing with $N(\mathrm{H_2})$ after $\gtrsim 10^{22}~{\mathrm{cm^{-2}}}$. The structures with and without high-column-density ($> 10^{22}~\mathrm{cm^{-2}}$) pixels show different $蟽_v^{\mathrm{pix}} \propto N(\mathrm{H_2})^尉$ relations, where the mean (std) $尉$ values are $0.38~(0.14)$ and $0.62~(0.27)$, respectively. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15034v1-abstract-full').style.display = 'none'; document.getElementById('2410.15034v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 12 figures, accepted for publication in Research in Astronomy and Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.12089">arXiv:2410.12089</a> <span> [<a href="https://arxiv.org/pdf/2410.12089">pdf</a>, <a href="https://arxiv.org/format/2410.12089">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> </div> <p class="title is-5 mathjax"> BICEP/Keck XVIII: Measurement of BICEP3 polarization angles and consequences for constraining cosmic birefringence and inflation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Collaboration%2C+B">BICEP/Keck Collaboration</a>, <a href="/search/astro-ph?searchtype=author&query=%3A"> :</a>, <a href="/search/astro-ph?searchtype=author&query=Ade%2C+P+A+R">P. A. R. Ade</a>, <a href="/search/astro-ph?searchtype=author&query=Ahmed%2C+Z">Z. Ahmed</a>, <a href="/search/astro-ph?searchtype=author&query=Amiri%2C+M">M. Amiri</a>, <a href="/search/astro-ph?searchtype=author&query=Barkats%2C+D">D. Barkats</a>, <a href="/search/astro-ph?searchtype=author&query=Thakur%2C+R+B">R. Basu Thakur</a>, <a href="/search/astro-ph?searchtype=author&query=Bischoff%2C+C+A">C. A. Bischoff</a>, <a href="/search/astro-ph?searchtype=author&query=Beck%2C+D">D. Beck</a>, <a href="/search/astro-ph?searchtype=author&query=Bock%2C+J+J">J. J. Bock</a>, <a href="/search/astro-ph?searchtype=author&query=Boenish%2C+H">H. Boenish</a>, <a href="/search/astro-ph?searchtype=author&query=Buza%2C+V">V. Buza</a>, <a href="/search/astro-ph?searchtype=author&query=Cheshire%2C+J+R">J. R. Cheshire IV</a>, <a href="/search/astro-ph?searchtype=author&query=Connors%2C+J">J. Connors</a>, <a href="/search/astro-ph?searchtype=author&query=Cornelison%2C+J">J. Cornelison</a>, <a href="/search/astro-ph?searchtype=author&query=Crumrine%2C+M">M. Crumrine</a>, <a href="/search/astro-ph?searchtype=author&query=Cukierman%2C+A+J">A. J. Cukierman</a>, <a href="/search/astro-ph?searchtype=author&query=Denison%2C+E">E. Denison</a>, <a href="/search/astro-ph?searchtype=author&query=Duband%2C+L">L. Duband</a>, <a href="/search/astro-ph?searchtype=author&query=Eiben%2C+M">M. Eiben</a>, <a href="/search/astro-ph?searchtype=author&query=Elwood%2C+B+D">B. D. Elwood</a>, <a href="/search/astro-ph?searchtype=author&query=Fatigoni%2C+S">S. Fatigoni</a>, <a href="/search/astro-ph?searchtype=author&query=Filippini%2C+J+P">J. P. Filippini</a>, <a href="/search/astro-ph?searchtype=author&query=Fortes%2C+A">A. Fortes</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+M">M. Gao</a> , et al. (61 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.12089v2-abstract-short" style="display: inline;"> We use a custom-made calibrator to measure individual detectors' polarization angles of BICEP3, a small aperture telescope observing the cosmic microwave background (CMB) at 95GHz from the South Pole. We describe our calibration strategy and the statistical and systematic uncertainties associated with the measurement. We reach an unprecedented precision for such measurement on a CMB experiment, wi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.12089v2-abstract-full').style.display = 'inline'; document.getElementById('2410.12089v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.12089v2-abstract-full" style="display: none;"> We use a custom-made calibrator to measure individual detectors' polarization angles of BICEP3, a small aperture telescope observing the cosmic microwave background (CMB) at 95GHz from the South Pole. We describe our calibration strategy and the statistical and systematic uncertainties associated with the measurement. We reach an unprecedented precision for such measurement on a CMB experiment, with a repeatability for each detector pair of $0.02掳$. We show that the relative angles measured using this method are in excellent agreement with those extracted from CMB data. Because the absolute measurement is currently limited by a systematic uncertainty, we do not derive cosmic birefringence constraints from BICEP3 data in this work. Rather, we forecast the sensitivity of BICEP3 sky maps for such analysis. We investigate the relative contributions of instrument noise, lensing, and dust, as well as astrophysical and instrumental systematics. We also explore the constraining power of different angle estimators, depending on analysis choices. We establish that the BICEP3 2-year dataset (2017--2018) has an on-sky sensitivity to the cosmic birefringence angle of $蟽= 0.078掳$, which could be improved to $蟽= 0.055掳$ by adding all of the existing BICEP3 data (through 2023). Furthermore, we emphasize the possibility of using the BICEP3 sky patch as a polarization calibration source for CMB experiments, which with the present data could reach a precision of $0.035掳$. Finally, in the context of inflation searches, we investigate the impact of detector-to-detector variations in polarization angles as they may bias the tensor-to-scalar ratio r. We show that while the effect is expected to remain subdominant to other sources of systematic uncertainty, it can be reliably calibrated using polarization angle measurements such as the ones we present in this paper. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.12089v2-abstract-full').style.display = 'none'; document.getElementById('2410.12089v2-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">29 Pages, 17 Figures, 6 Tables, as submitted to PRD</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.07453">arXiv:2410.07453</a> <span> [<a href="https://arxiv.org/pdf/2410.07453">pdf</a>, <a href="https://arxiv.org/format/2410.07453">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/ad5bdb">10.3847/1538-3881/ad5bdb <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First Very Long Baseline Interferometry Detections at 870渭m </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Raymond%2C+A+W">Alexander W. Raymond</a>, <a href="/search/astro-ph?searchtype=author&query=Doeleman%2C+S+S">Sheperd S. Doeleman</a>, <a href="/search/astro-ph?searchtype=author&query=Asada%2C+K">Keiichi Asada</a>, <a href="/search/astro-ph?searchtype=author&query=Blackburn%2C+L">Lindy Blackburn</a>, <a href="/search/astro-ph?searchtype=author&query=Bower%2C+G+C">Geoffrey C. Bower</a>, <a href="/search/astro-ph?searchtype=author&query=Bremer%2C+M">Michael Bremer</a>, <a href="/search/astro-ph?searchtype=author&query=Broguiere%2C+D">Dominique Broguiere</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+M">Ming-Tang Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Crew%2C+G+B">Geoffrey B. Crew</a>, <a href="/search/astro-ph?searchtype=author&query=Dornbusch%2C+S">Sven Dornbusch</a>, <a href="/search/astro-ph?searchtype=author&query=Fish%2C+V+L">Vincent L. Fish</a>, <a href="/search/astro-ph?searchtype=author&query=Garc%C3%ADa%2C+R">Roberto Garc铆a</a>, <a href="/search/astro-ph?searchtype=author&query=Gentaz%2C+O">Olivier Gentaz</a>, <a href="/search/astro-ph?searchtype=author&query=Goddi%2C+C">Ciriaco Goddi</a>, <a href="/search/astro-ph?searchtype=author&query=Han%2C+C">Chih-Chiang Han</a>, <a href="/search/astro-ph?searchtype=author&query=Hecht%2C+M+H">Michael H. Hecht</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y">Yau-De Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Janssen%2C+M">Michael Janssen</a>, <a href="/search/astro-ph?searchtype=author&query=Keating%2C+G+K">Garrett K. Keating</a>, <a href="/search/astro-ph?searchtype=author&query=Koay%2C+J+Y">Jun Yi Koay</a>, <a href="/search/astro-ph?searchtype=author&query=Krichbaum%2C+T+P">Thomas P. Krichbaum</a>, <a href="/search/astro-ph?searchtype=author&query=Lo%2C+W">Wen-Ping Lo</a>, <a href="/search/astro-ph?searchtype=author&query=Matsushita%2C+S">Satoki Matsushita</a>, <a href="/search/astro-ph?searchtype=author&query=Matthews%2C+L+D">Lynn D. Matthews</a>, <a href="/search/astro-ph?searchtype=author&query=Moran%2C+J+M">James M. Moran</a> , et al. (254 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="2410.07453v1-abstract-short" style="display: inline;"> The first very long baseline interferometry (VLBI) detections at 870$渭$m wavelength (345$\,$GHz frequency) are reported, achieving the highest diffraction-limited angular resolution yet obtained from the surface of the Earth, and the highest-frequency example of the VLBI technique to date. These include strong detections for multiple sources observed on inter-continental baselines between telescop… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.07453v1-abstract-full').style.display = 'inline'; document.getElementById('2410.07453v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.07453v1-abstract-full" style="display: none;"> The first very long baseline interferometry (VLBI) detections at 870$渭$m wavelength (345$\,$GHz frequency) are reported, achieving the highest diffraction-limited angular resolution yet obtained from the surface of the Earth, and the highest-frequency example of the VLBI technique to date. These include strong detections for multiple sources observed on inter-continental baselines between telescopes in Chile, Hawaii, and Spain, obtained during observations in October 2018. The longest-baseline detections approach 11$\,$G$位$ corresponding to an angular resolution, or fringe spacing, of 19$渭$as. The Allan deviation of the visibility phase at 870$渭$m is comparable to that at 1.3$\,$mm on the relevant integration time scales between 2 and 100$\,$s. The detections confirm that the sensitivity and signal chain stability of stations in the Event Horizon Telescope (EHT) array are suitable for VLBI observations at 870$渭$m. Operation at this short wavelength, combined with anticipated enhancements of the EHT, will lead to a unique high angular resolution instrument for black hole studies, capable of resolving the event horizons of supermassive black holes in both space and time. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.07453v1-abstract-full').style.display = 'none'; document.getElementById('2410.07453v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Corresponding author: S. Doeleman</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astronomical Journal, Volume 168, Issue 3, id.130, 19 pp. 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.04963">arXiv:2410.04963</a> <span> [<a href="https://arxiv.org/pdf/2410.04963">pdf</a>, <a href="https://arxiv.org/format/2410.04963">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A systematic study of Millihertz Quasi-periodic Oscillations in GS 1826-238 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Xiao%2C+H">Hua Xiao</a>, <a href="/search/astro-ph?searchtype=author&query=Ji%2C+L">Long Ji</a>, <a href="/search/astro-ph?searchtype=author&query=Tsygankov%2C+S">Sergey Tsygankov</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yupeng Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shu Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+Z">Zhaosheng Li</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.04963v1-abstract-short" style="display: inline;"> We performed a systematic investigation of millihertz quasi-periodic oscillations (mHz QPOs) in the low-mass X-ray binary GS 1826$-$238 observed with NICER and Insight-HXMT. We discovered 35 time intervals exhibiting mHz QPOs out of 106 GTI samples in the frequency range of 4.2-12.8 mHz at a significance level of $>5蟽$. The source remains in a soft state in our study. No significant differences ar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.04963v1-abstract-full').style.display = 'inline'; document.getElementById('2410.04963v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.04963v1-abstract-full" style="display: none;"> We performed a systematic investigation of millihertz quasi-periodic oscillations (mHz QPOs) in the low-mass X-ray binary GS 1826$-$238 observed with NICER and Insight-HXMT. We discovered 35 time intervals exhibiting mHz QPOs out of 106 GTI samples in the frequency range of 4.2-12.8 mHz at a significance level of $>5蟽$. The source remains in a soft state in our study. No significant differences are found between the samples with and without mHz QPOs according to positions in the color-color and hardness-intensity diagrams. These QPOs were discovered at an accretion rate of $\sim 0.1 \dot{M}_{\rm Edd}$, similar to other sources. The broadband spectrum of GS 1826$-$238 can be modeled as a combination of a multi-color blackbody from the accretion disk and a Comptonization with seed photons emitted from the NS surface. The flux modulations of mHz QPOs are related to variations of the temperature of Comptonization seed photons, consistent with the marginally stable burning theory. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.04963v1-abstract-full').style.display = 'none'; document.getElementById('2410.04963v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 figures, 1 table, submitted to 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/2410.04425">arXiv:2410.04425</a> <span> [<a href="https://arxiv.org/pdf/2410.04425">pdf</a>, <a href="https://arxiv.org/format/2410.04425">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"> LHAASO detection of very-high-energy gamma-ray emission surrounding PSR J0248+6021 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Zhen Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=An%2C+Q">Q. An</a>, <a href="/search/astro-ph?searchtype=author&query=Axikegu"> Axikegu</a>, <a href="/search/astro-ph?searchtype=author&query=Bai%2C+Y+X">Y. X. Bai</a>, <a href="/search/astro-ph?searchtype=author&query=Bao%2C+Y+W">Y. W. Bao</a>, <a href="/search/astro-ph?searchtype=author&query=Bastieri%2C+D">D. Bastieri</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Bi%2C+Y+J">Y. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+J+T">J. T. Cai</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Q">Q. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+W+Y">W. Y. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Zhe Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Chang%2C+J">J. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chang%2C+J+F">J. F. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+A+M">A. M. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+E+S">E. S. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Liang Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Lin Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">Long Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+M+J">M. J. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+M+L">M. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Q+H">Q. H. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S+H">S. H. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+S+Z">S. Z. Chen</a> , et al. (255 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="2410.04425v2-abstract-short" style="display: inline;"> We report the detection of an extended very-high-energy (VHE) gamma-ray source coincident with the location of middle-aged (62.4~\rm kyr) pulsar PSR J0248+6021, by using the LHAASO-WCDA data of live 796 days and LHAASO-KM2A data of live 1216 days. A significant excess of \gray induced showers is observed both by WCDA in energy bands of 1-25~\rm TeV and KM2A in energy bands of $>$ 25~\rm TeV with 7… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.04425v2-abstract-full').style.display = 'inline'; document.getElementById('2410.04425v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.04425v2-abstract-full" style="display: none;"> We report the detection of an extended very-high-energy (VHE) gamma-ray source coincident with the location of middle-aged (62.4~\rm kyr) pulsar PSR J0248+6021, by using the LHAASO-WCDA data of live 796 days and LHAASO-KM2A data of live 1216 days. A significant excess of \gray induced showers is observed both by WCDA in energy bands of 1-25~\rm TeV and KM2A in energy bands of $>$ 25~\rm TeV with 7.3 $蟽$ and 13.5 $蟽$, respectively. The best-fit position derived through WCDA data is R.A. = 42.06$^\circ \pm$ 0.12$^\circ$ and Dec. = 60.24$^\circ \pm $ 0.13$^\circ$ with an extension of 0.69$^\circ\pm$0.15$^\circ$ and that of the KM2A data is R.A.= 42.29$^\circ \pm $ 0.13$^\circ$ and Dec. = 60.38$^\circ \pm$ 0.07$^\circ$ with an extension of 0.37$^\circ\pm$0.07$^\circ$. No clear extended multiwavelength counterpart of this LHAASO source has been found from the radio band to the GeV band. The most plausible explanation of the VHE \gray emission is the inverse Compton process of highly relativistic electrons and positrons injected by the pulsar. These electrons/positrons are hypothesized to be either confined within the pulsar wind nebula or to have already escaped into the interstellar medium, forming a pulsar halo. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.04425v2-abstract-full').style.display = 'none'; document.getElementById('2410.04425v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 10 figures, Accepted by Sci. China-Phys. Mech. Astron</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.03823">arXiv:2410.03823</a> <span> [<a href="https://arxiv.org/pdf/2410.03823">pdf</a>, <a href="https://arxiv.org/format/2410.03823">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> High Resolution ALMA Observations of Richly Structured Protoplanetary Disks in $蟽$ Orionis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Huang%2C+J">Jane Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Ansdell%2C+M">Megan Ansdell</a>, <a href="/search/astro-ph?searchtype=author&query=Birnstiel%2C+T">Tilman Birnstiel</a>, <a href="/search/astro-ph?searchtype=author&query=Czekala%2C+I">Ian Czekala</a>, <a href="/search/astro-ph?searchtype=author&query=Long%2C+F">Feng Long</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+J">Jonathan Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+S">Shangjia Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+Z">Zhaohuan Zhu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.03823v2-abstract-short" style="display: inline;"> ALMA has detected substructures in numerous protoplanetary disks at radii from a few to over a hundred au. These substructures are commonly thought to be associated with planet formation, either by serving as sites fostering planetesimal formation or arising as a consequence of planet-disk interactions. Our current understanding of substructures, though, is primarily based on observations of nearb… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.03823v2-abstract-full').style.display = 'inline'; document.getElementById('2410.03823v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.03823v2-abstract-full" style="display: none;"> ALMA has detected substructures in numerous protoplanetary disks at radii from a few to over a hundred au. These substructures are commonly thought to be associated with planet formation, either by serving as sites fostering planetesimal formation or arising as a consequence of planet-disk interactions. Our current understanding of substructures, though, is primarily based on observations of nearby star-forming regions with mild UV environments, whereas stars are typically born in much harsher UV environments, which may inhibit planet formation in the outer disk through external photoevaporation. We present high resolution ($\sim8$ au) ALMA 1.3 mm continuum images of eight disks in $蟽$ Orionis, a cluster irradiated by an O9.5 star. Gaps and rings are resolved in the images of five disks. The most striking of these is SO 1274, which features five gaps that appear to be arranged nearly in a resonant chain. In addition, we infer the presence of gap or shoulder-like structures in the other three disks through visibility modeling. These observations indicate that substructures robustly form and survive at semi-major axes of several tens of au or less in disks exposed to intermediate levels of external UV radiation as well as in compact disks. However, our observations also suggest that disks in $蟽$ Orionis are mostly small and thus millimeter continuum gaps beyond a disk radius of 50 au are rare in this region, possibly due to either external photoevaporation or age effects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.03823v2-abstract-full').style.display = 'none'; document.getElementById('2410.03823v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by ApJ, typos corrected from v1</span> </p> </li> 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