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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=Jiao%2C+Y&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Jiao%2C+Y&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Jiao%2C+Y&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2502.15447">arXiv:2502.15447</a> <span> [<a href="https://arxiv.org/pdf/2502.15447">pdf</a>, <a href="https://arxiv.org/format/2502.15447">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> <div 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.xinn.2025.100802">10.1016/j.xinn.2025.100802 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ultra-high-energy $纬$-ray emission associated with the tail of a bow-shock pulsar wind nebula </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=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=Bian%2C+W">W. Bian</a>, <a href="/search/astro-ph?searchtype=author&query=Bukevich%2C+A+V">A. V. Bukevich</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+C+M">C. M. Cai</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+H+X">H. X. 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">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">S. 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. (274 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="2502.15447v2-abstract-short" style="display: inline;"> In this study, we present a comprehensive analysis of an unidentified point-like ultra-high-energy (UHE) $纬$-ray source, designated as 1LHAASO J1740+0948u, situated in the vicinity of the middle-aged pulsar PSR J1740+1000. The detection significance reached 17.1$蟽$ (9.4$蟽$) above 25$\,$TeV (100$\,$TeV). The source energy spectrum extended up to 300$\,$TeV, which was well fitted by a log-parabola f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.15447v2-abstract-full').style.display = 'inline'; document.getElementById('2502.15447v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.15447v2-abstract-full" style="display: none;"> In this study, we present a comprehensive analysis of an unidentified point-like ultra-high-energy (UHE) $纬$-ray source, designated as 1LHAASO J1740+0948u, situated in the vicinity of the middle-aged pulsar PSR J1740+1000. The detection significance reached 17.1$蟽$ (9.4$蟽$) above 25$\,$TeV (100$\,$TeV). The source energy spectrum extended up to 300$\,$TeV, which was well fitted by a log-parabola function with $N0 = (1.93\pm0.23) \times 10^{-16} \rm{TeV^{-1}\,cm^{-2}\,s^{-2}}$, $伪= 2.14\pm0.27$, and $尾= 1.20\pm0.41$ at E0 = 30$\,$TeV. The associated pulsar, PSR J1740+1000, resides at a high galactic latitude and powers a bow-shock pulsar wind nebula (BSPWN) with an extended X-ray tail. The best-fit position of the gamma-ray source appeared to be shifted by $0.2^{\circ}$ with respect to the pulsar position. As the (i) currently identified pulsar halos do not demonstrate such offsets, and (ii) centroid of the gamma-ray emission is approximately located at the extension of the X-ray tail, we speculate that the UHE $纬$-ray emission may originate from re-accelerated electron/positron pairs that are advected away in the bow-shock tail. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.15447v2-abstract-full').style.display = 'none'; document.getElementById('2502.15447v2-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 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Corrected spelling errors in several author names</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Innovation (2025), 100802 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2502.04848">arXiv:2502.04848</a> <span> [<a href="https://arxiv.org/pdf/2502.04848">pdf</a>, <a href="https://arxiv.org/format/2502.04848">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"> Broadband $纬$-ray spectrum of supernova remnant Cassiopeia A </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=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=Bian%2C+W">W. Bian</a>, <a href="/search/astro-ph?searchtype=author&query=Bukevich%2C+A+V">A. V. Bukevich</a>, <a href="/search/astro-ph?searchtype=author&query=Cai%2C+C+M">C. M. Cai</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+H+X">H. X. 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">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">S. 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. (293 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="2502.04848v1-abstract-short" style="display: inline;"> The core-collapse supernova remnant (SNR) Cassiopeia A (Cas A) is one of the brightest galactic radio sources with an angular radius of $\sim$ 2.5 $\arcmin$. Although no extension of this source has been detected in the $纬$-ray band, using more than 1000 days of LHAASO data above $\sim 0.8$ TeV, we find that its spectrum is significantly softer than those obtained with Imaging Air Cherenkov Telesc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.04848v1-abstract-full').style.display = 'inline'; document.getElementById('2502.04848v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.04848v1-abstract-full" style="display: none;"> The core-collapse supernova remnant (SNR) Cassiopeia A (Cas A) is one of the brightest galactic radio sources with an angular radius of $\sim$ 2.5 $\arcmin$. Although no extension of this source has been detected in the $纬$-ray band, using more than 1000 days of LHAASO data above $\sim 0.8$ TeV, we find that its spectrum is significantly softer than those obtained with Imaging Air Cherenkov Telescopes (IACTs) and its flux near $\sim 1$ TeV is about two times higher. In combination with analyses of more than 16 years of \textit{Fermi}-LAT data covering $0.1 \, \mathrm{GeV} - 1 \, \mathrm{TeV}$, we find that the spectrum above 30 GeV deviates significantly from a single power-law, and is best described by a smoothly broken power-law with a spectral index of $1.90 \pm 0.15_\mathrm{stat}$ ($3.41 \pm 0.19_\mathrm{stat}$) below (above) a break energy of $0.63 \pm 0.21_\mathrm{stat} \, \mathrm{TeV}$. Given differences in the angular resolution of LHAASO-WCDA and IACTs, TeV $纬$-ray emission detected with LHAASO may have a significant contribution from regions surrounding the SNR illuminated by particles accelerated earlier, which, however, are treated as background by IACTs. Detailed modelling can be used to constrain acceleration processes of TeV particles in the early stage of SNR evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.04848v1-abstract-full').style.display = 'none'; document.getElementById('2502.04848v1-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 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.04218">arXiv:2412.04218</a> <span> [<a href="https://arxiv.org/pdf/2412.04218">pdf</a>, <a href="https://arxiv.org/format/2412.04218">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</span> </div> </div> <p class="title is-5 mathjax"> Gravitational wave and dark matter from Axion-Higgs string </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yongtao Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Bian%2C+L">Ligong Bian</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="2412.04218v1-abstract-short" style="display: inline;"> Axions have long been considered plausible candidates for dark matter. The axion dark matter emitted from cosmic strings after the Peccei-Quinn (PQ) symmetry breaking in the early Universe was extensively simulated. In this work, we study dark matter and gravitational waves through the lattice simulation of the Axion-Higgs string. We gave the dark matter overproduction and the Big Bang nucleosynth… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.04218v1-abstract-full').style.display = 'inline'; document.getElementById('2412.04218v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.04218v1-abstract-full" style="display: none;"> Axions have long been considered plausible candidates for dark matter. The axion dark matter emitted from cosmic strings after the Peccei-Quinn (PQ) symmetry breaking in the early Universe was extensively simulated. In this work, we study dark matter and gravitational waves through the lattice simulation of the Axion-Higgs string. We gave the dark matter overproduction and the Big Bang nucleosynthesis bounds on the axion decay constant $f_a$ and the axion mass $m_a$ for axion-like particles, and found that the predicted gravitational wave spectra cannot be probed by the dataset of the current pulsar timing array experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.04218v1-abstract-full').style.display = 'none'; document.getElementById('2412.04218v1-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 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">11 pages, 13 figures, comments welcome!</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.02737">arXiv:2412.02737</a> <span> [<a href="https://arxiv.org/pdf/2412.02737">pdf</a>, <a href="https://arxiv.org/format/2412.02737">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="General Relativity and Quantum Cosmology">gr-qc</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/10.1051/0004-6361/202452753">10.1051/0004-6361/202452753 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Dark matter fraction derived from the M31 rotation curve </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">F. Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y+B">Y. B. Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Amram%2C+P">P. Amram</a>, <a href="/search/astro-ph?searchtype=author&query=Chemin%2C+L">L. Chemin</a>, <a href="/search/astro-ph?searchtype=author&query=Mamon%2C+G+A">G. A. Mamon</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J+L">J. L. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Akib%2C+I">I. Akib</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y+J">Y. J. Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H+F">H. F. 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="2412.02737v5-abstract-short" style="display: inline;"> Mass estimates of a spiral galaxy derived from its rotation curve must account for the galaxy's past accretion history. There are several lines of evidence indicating that M31 experienced a major merger 2 to 3 Gyr ago. Here, we have generated a dynamical model of M31 as a merger remnant that reproduces most of its properties, from the central bar to the outskirts. The model accounts for the past m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02737v5-abstract-full').style.display = 'inline'; document.getElementById('2412.02737v5-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.02737v5-abstract-full" style="display: none;"> Mass estimates of a spiral galaxy derived from its rotation curve must account for the galaxy's past accretion history. There are several lines of evidence indicating that M31 experienced a major merger 2 to 3 Gyr ago. Here, we have generated a dynamical model of M31 as a merger remnant that reproduces most of its properties, from the central bar to the outskirts. The model accounts for the past major merger, and reproduces the details of M31's rotation curve, including its 14 kpc bump and the observed increase of velocity beyond 25 kpc. Furthermore, we find non-equilibrium and oscillatory motions in the gas of the merger-remnant outskirts caused by material in a tidal tail returning to the merger remnant. A total dynamical M31 mass of 4.5 $\times 10^{11} M_{\odot}$ within 137 kpc has been obtained after scaling it to the observed HI rotation curve. Within this radial distance, 68% of the total dynamical mass is dark. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02737v5-abstract-full').style.display = 'none'; document.getElementById('2412.02737v5-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 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 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">A&A, 9 pages, 10 Figures, see also a video showing the formation of the M31 gas disk and of its rotation curve at https://www.youtube.com/watch?v=_W8tdlUbv2k</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 694, A16 (2025) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.12432">arXiv:2411.12432</a> <span> [<a href="https://arxiv.org/pdf/2411.12432">pdf</a>, <a href="https://arxiv.org/format/2411.12432">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202452294">10.1051/0004-6361/202452294 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Investigating the vertical distribution of the disk as a function of radial action: Results from simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yunpeng Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+C">Chengqun Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yuqin Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Du%2C+C">Cuihua Du</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+G">Gang Zhao</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="2411.12432v1-abstract-short" style="display: inline;"> Previous research has established a relationship between radial action and scale height in Galactic disks, unveiling a correlation between radial and vertical heating. This finding poses a challenge to our existing comprehension of heating theories and consequently encodes crucial insights into the formation and heating history of Galactic disks. In this study, we perform N-body simulations with t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.12432v1-abstract-full').style.display = 'inline'; document.getElementById('2411.12432v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.12432v1-abstract-full" style="display: none;"> Previous research has established a relationship between radial action and scale height in Galactic disks, unveiling a correlation between radial and vertical heating. This finding poses a challenge to our existing comprehension of heating theories and consequently encodes crucial insights into the formation and heating history of Galactic disks. In this study, we perform N-body simulations with the aim of verifying the existence of this correlation between radial action and scale height, thereby enhancing our comprehension of the heating history of Galactic disks. We find that the relationship between radial action and scale height in our simulations can be described by the same functional form observed in previous work. Furthermore, the relationships derived from our simulations align well with those of the Galactic thin disk. However, they do not coincide with the inner thick disk but exhibit a rough correspondence with the outer thick disk, suggesting the possibility that additional heating mechanisms may be required to explain the inner thick disk. We also find that the mean radial action and scale height undergo rapid increases during the initial stages of the simulation, yet remain relatively unchanged as the disk evolves further. By tracing example particles, we uncover a correlation between radial and vertical heating in our simulation: as a particle in the disk gains or loses radial action, its vertical motion tends to oscillate on a more or less extended orbit, accompanied by a tendency to migrate outward or inward, respectively. The massive, long-lasting particles in our simulation contribute to disk heating by solely enhancing the rate of increase in scale height with radial action, while maintaining the functional form that describes the relationship between these two variables. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.12432v1-abstract-full').style.display = 'none'; document.getElementById('2411.12432v1-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 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">6 pages, 5 figures,accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, 2024, 692, A167 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.10531">arXiv:2411.10531</a> <span> [<a href="https://arxiv.org/pdf/2411.10531">pdf</a>, <a href="https://arxiv.org/format/2411.10531">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Searching for GeV Gamma-Ray Polarization and Axion-Like Particles with AMS-02 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+X">Xiuyuan Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yi Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Slatyer%2C+T+R">Tracy R. Slatyer</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="2411.10531v1-abstract-short" style="display: inline;"> We study the detectability of GeV-band gamma-ray polarization with the AMS-02 experiment and a proposed successor, from Galactic and extragalactic sources. Characterizing gamma-ray polarization in this energy range could shed light on gamma-ray emission mechanisms in the sources; physics beyond the Standard Model, such as the presence of axion-like particles (ALPs), could also induce a distinctive… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.10531v1-abstract-full').style.display = 'inline'; document.getElementById('2411.10531v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.10531v1-abstract-full" style="display: none;"> We study the detectability of GeV-band gamma-ray polarization with the AMS-02 experiment and a proposed successor, from Galactic and extragalactic sources. Characterizing gamma-ray polarization in this energy range could shed light on gamma-ray emission mechanisms in the sources; physics beyond the Standard Model, such as the presence of axion-like particles (ALPs), could also induce a distinctive energy-dependent polarization signal due to propagation effects in magnetic fields. We present estimates for the minimum detectable polarization from bright sources and the forecast reach for axion-like particles (ALPs). We show that for an example bright extragalactic source (NGC1275), AMS-02 will only have sensitivity to ALP-induced polarization from currently open parameter space if the B-field configuration is unusually favorable to a signal. However, a successor experiment such as AMS-100 would be expected to probe new parameter space even for pessimistic B-field models, with prospects to measure the energy-dependence of such a signal. For Galactic sources, polarization measurements could provide a unique test of scenarios where ALPs induce energy-dependent features in the photon intensity. However, in the absence of a bright transient source (such as a Galactic supernova), the parameter space that would be probed by this approach with ten years of AMS-100 data is already nominally excluded by other experiments, although this conflict may be avoided in specific ALP models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.10531v1-abstract-full').style.display = 'none'; document.getElementById('2411.10531v1-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">18+2 pages, 11+2 figures. Comments welcome</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> MIT-CTP/5791 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.07281">arXiv:2411.07281</a> <span> [<a href="https://arxiv.org/pdf/2411.07281">pdf</a>, <a href="https://arxiv.org/format/2411.07281">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="General Relativity and Quantum Cosmology">gr-qc</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/10.1051/0004-6361/202451381">10.1051/0004-6361/202451381 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Milky Way accretion history compared to cosmological simulations -- from bulge to dwarf galaxy infall </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">F. Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y+J">Y. J. Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Mamon%2C+G+A">G. A. Mamon</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y+B">Y. B. Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Akib%2C+I">I. Akib</a>, <a href="/search/astro-ph?searchtype=author&query=Amram%2C+P">P. Amram</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H+F">H. F. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J+L">J. L. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Chemin%2C+L">L. Chemin</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="2411.07281v5-abstract-short" style="display: inline;"> Galactic halos are known to grow hierarchically, inside out. This implies a correlation between the infall lookback time of satellites and their binding energy. Cosmological simulations predict a linear relation between the infall lookback time and the logarithm of the binding energy, with a small scatter. Gaia measurements of the bulk proper motions of globular clusters and dwarf satellites of th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.07281v5-abstract-full').style.display = 'inline'; document.getElementById('2411.07281v5-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.07281v5-abstract-full" style="display: none;"> Galactic halos are known to grow hierarchically, inside out. This implies a correlation between the infall lookback time of satellites and their binding energy. Cosmological simulations predict a linear relation between the infall lookback time and the logarithm of the binding energy, with a small scatter. Gaia measurements of the bulk proper motions of globular clusters and dwarf satellites of the Milky Way are sufficiently accurate to establish the kinetic energies of these systems. Assuming the gravitational potential of the Milky Way, we can deduce the binding energies of the dwarf satellites and those of the galaxies that were previously accreted by the Milky Way. This can be compared to cosmological simulations for the first time. The relation of the infall lookback time versus binding energy we found in a cosmological simulation matches that for the early accretion events when the simulated total Milky Way mass within 21 kpc was rescaled to 2 $10^{11}$ solar masses. This agrees well with previous estimates from globular cluster kinematics and from the rotation curve. However, the vast majority of the dwarf galaxies are clear outliers to this rescaled relation, unless they are very recent infallers. In other words, the very low binding energies of most dwarf galaxies compared to Sgr and previous accreted galaxies suggests that most of them were accreted much later than 8 or even 5 Gyr ago. We also found that the subhalo systems in some cosmological simulations are too dynamically hot when they are compared to identified Milky Way substructures. This leads to an overestimated impact of satellites on the Galaxy rotation curve. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.07281v5-abstract-full').style.display = 'none'; document.getElementById('2411.07281v5-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 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">A&A Letters Volume 692, December 2024, 5 pages, 2 Figures, and Appendix A & B, the late infall of dwarf galaxies is supported by the discovery of young stars in dSphs by Yang et al. 2024, see arXiv:2409.15414</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 692, L1 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.01215">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/2410.09328">arXiv:2410.09328</a> <span> [<a href="https://arxiv.org/pdf/2410.09328">pdf</a>, <a href="https://arxiv.org/ps/2410.09328">ps</a>, <a href="https://arxiv.org/format/2410.09328">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> On the Acceleration of the Young Solar Wind from Different Source Regions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yiming Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Y+D">Ying D. Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+W">Wenshuai Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Ran%2C+H">Hao Ran</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+R">Rui 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="2410.09328v2-abstract-short" style="display: inline;"> The acceleration of the young solar wind is studied using the first 17 encounters of Parker Solar Probe. We identify wind intervals from different source regions: coronal hole (CH) interiors, streamers, and low Mach number boundary layers (LMBLs), i.e. the inner boundaries of coronal holes. We present their statistical trends in the acceleration process. Most of the observations can be reproduced… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.09328v2-abstract-full').style.display = 'inline'; document.getElementById('2410.09328v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.09328v2-abstract-full" style="display: none;"> The acceleration of the young solar wind is studied using the first 17 encounters of Parker Solar Probe. We identify wind intervals from different source regions: coronal hole (CH) interiors, streamers, and low Mach number boundary layers (LMBLs), i.e. the inner boundaries of coronal holes. We present their statistical trends in the acceleration process. Most of the observations can be reproduced by a two-fluid hydrodynamic model with realistic corona temperatures. In such a model, the solar wind is accelerated by the combined thermal pressures of protons and electrons,but it is mainly the difference in the proton pressure that leads to the difference in the solar wind speed. The proton pressure is the highest in the fastest CH wind, with a high initial proton temperature that decreases slowly. It is lower in the relatively slow LMBL wind, and the lowest in the slowest streamer wind. The proton temperature is quadratically correlated with the wind speed when scaled to the same distance. In contrast, the electron temperature shows no significant differences for different wind types or wind speeds, indicating more similar contributions from the electron pressure. The model gives reasonable locations for the sonic critical point, which is on average at 3.6-7.3 solar radii and can also extend to large distances when the proton temperature is extremely low, as in the LMBL wind. In addition to the thermal pressure, we raise the possibility that Alfv茅n waves may contribute to the solar wind acceleration, especially for the fast CH wind. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.09328v2-abstract-full').style.display = 'none'; document.getElementById('2410.09328v2-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 11 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 by ApJ 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/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/2407.19219">arXiv:2407.19219</a> <span> [<a href="https://arxiv.org/pdf/2407.19219">pdf</a>, <a href="https://arxiv.org/format/2407.19219">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stae1851">10.1093/mnras/stae1851 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Primeval very low-mass stars and brown dwarfs -- VIII. The first age benchmark L subdwarf, a wide companion to a halo white dwarf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Raddi%2C+R">R. Raddi</a>, <a href="/search/astro-ph?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/astro-ph?searchtype=author&query=Casewell%2C+S+L">S. L. Casewell</a>, <a href="/search/astro-ph?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/astro-ph?searchtype=author&query=Galvez-Ortiz%2C+M+C">M. C. Galvez-Ortiz</a>, <a href="/search/astro-ph?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Baig%2C+S">S. Baig</a>, <a href="/search/astro-ph?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/astro-ph?searchtype=author&query=Gauza%2C+B">B. Gauza</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+Y+V">Ya. V. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y+F">Y. F. Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+Z+K">Z. K. Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+S+Y">S. Y. Zhou</a>, <a href="/search/astro-ph?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</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="2407.19219v3-abstract-short" style="display: inline;"> We report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV 1256-62AB, a gravitationally bound system located 75.6(+1.9/-1.8) pc away with a projected separation of 1375(+35/-33) au. The primary is a cool DC white dwarf with a hydrogen dom… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.19219v3-abstract-full').style.display = 'inline'; document.getElementById('2407.19219v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.19219v3-abstract-full" style="display: none;"> We report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV 1256-62AB, a gravitationally bound system located 75.6(+1.9/-1.8) pc away with a projected separation of 1375(+35/-33) au. The primary is a cool DC white dwarf with a hydrogen dominated atmosphere, and has a total age of 10.5(+3.3/-2.1) Gyr, based on white dwarf model fitting. The secondary is an L subdwarf with a metallicity of [M/H] = -0.72(+0.08/-0.10) (i.e. [Fe/H] = -0.81+/-0.10) and Teff = 2298(+45/-43) K based on atmospheric model fitting of its optical to near infrared spectrum, and likely has a mass just above the stellar/substellar boundary. The sub-solar metallicity of the L subdwarf and the system's total space velocity of 406 km/s indicates membership in the Galactic halo, and it has a flat eccentric Galactic orbit passing within 1~kpc of the centre of the Milky Way every ~0.4Gyr and extending to 15-31 kpc at apogal. VVV 1256-62B is the first L subdwarf to have a well-constrained age, making it an ideal benchmark of metal-poor ultracool dwarf atmospheres and evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.19219v3-abstract-full').style.display = 'none'; document.getElementById('2407.19219v3-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 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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, 12 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/2406.08698">arXiv:2406.08698</a> <span> [<a href="https://arxiv.org/pdf/2406.08698">pdf</a>, <a href="https://arxiv.org/format/2406.08698">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> </div> <p class="title is-5 mathjax"> Constraints on Ultra Heavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations </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="2406.08698v1-abstract-short" style="display: inline;"> In this work we try to search for signals generated by ultra-heavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible gamma-ray by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter which have low fluxes… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.08698v1-abstract-full').style.display = 'inline'; document.getElementById('2406.08698v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.08698v1-abstract-full" style="display: none;"> In this work we try to search for signals generated by ultra-heavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible gamma-ray by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter which have low fluxes of astrophysical $纬$-ray background while large amount of dark matter. By analyzing more than 700 days observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultra-heavy dark matter annihilation cross-section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.08698v1-abstract-full').style.display = 'none'; document.getElementById('2406.08698v1-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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, 12 figures, accepted by 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/2405.20411">arXiv:2405.20411</a> <span> [<a href="https://arxiv.org/pdf/2405.20411">pdf</a>, <a href="https://arxiv.org/format/2405.20411">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41550-024-02258-z">10.1038/s41550-024-02258-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroid Kamo`oalewa's journey from the lunar Giordano Bruno crater to Earth 1:1 resonance </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yifei Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+B">Bin Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y">Yukun Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Asphaug%2C+E">Erik Asphaug</a>, <a href="/search/astro-ph?searchtype=author&query=Gladman%2C+B">Brett Gladman</a>, <a href="/search/astro-ph?searchtype=author&query=Malhotra%2C+R">Renu Malhotra</a>, <a href="/search/astro-ph?searchtype=author&query=Michel%2C+P">Patrick Michel</a>, <a href="/search/astro-ph?searchtype=author&query=Yu%2C+Y">Yang Yu</a>, <a href="/search/astro-ph?searchtype=author&query=Baoyin%2C+H">Hexi Baoyin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.20411v1-abstract-short" style="display: inline;"> Among the nearly 30,000 known near-Earth asteroids (NEAs), only tens of them possess Earth co-orbital characteristics with semi-major axes $\sim$1 au. In particular, 469219 Kamo`oalewa (2016 HO3), upcoming target of China's Tianwen-2 asteroid sampling mission, exhibits a meta-stable 1:1 mean-motion resonance with Earth. Intriguingly, recent ground-based observations show that Kamo`oalewa has spect… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20411v1-abstract-full').style.display = 'inline'; document.getElementById('2405.20411v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.20411v1-abstract-full" style="display: none;"> Among the nearly 30,000 known near-Earth asteroids (NEAs), only tens of them possess Earth co-orbital characteristics with semi-major axes $\sim$1 au. In particular, 469219 Kamo`oalewa (2016 HO3), upcoming target of China's Tianwen-2 asteroid sampling mission, exhibits a meta-stable 1:1 mean-motion resonance with Earth. Intriguingly, recent ground-based observations show that Kamo`oalewa has spectroscopic characteristics similar to space-weathered lunar silicates, hinting at a lunar origin instead of an asteroidal one like the vast majority of NEAs. Here we use numerical simulations to demonstrate that Kamo`oalewa's physical and orbital properties are compatible with a fragment from a crater larger than 10--20 km formed on the Moon in the last few million years. The impact could have ejected sufficiently large fragments into heliocentric orbits, some of which could be transferred to Earth 1:1 resonance and persist today. This leads us to suggest the young lunar crater Giordano Bruno (22 km diameter, 1--10 Ma age) as the most likely source, linking a specific asteroid in space to its source crater on the Moon. The hypothesis will be tested by the Tianwen-2 mission when it returns a sample of Kamo`oalewa. And the upcoming NEO Surveyor mission will possibly help us to identify such a lunar-derived NEA population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20411v1-abstract-full').style.display = 'none'; document.getElementById('2405.20411v1-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">29 pages, 4 figures. Published in Nature Astronomy, 19 April 2024</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.11826">arXiv:2405.11826</a> <span> [<a href="https://arxiv.org/pdf/2405.11826">pdf</a>, <a href="https://arxiv.org/format/2405.11826">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 Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> Data quality control system and long-term performance monitor of the LHAASO-KM2A </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=Bian%2C+W">W. Bian</a>, <a href="/search/astro-ph?searchtype=author&query=Bukevich%2C+A+V">A. V. Bukevich</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+H+X">H. X. 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">S. Chen</a> , et al. (263 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="2405.11826v3-abstract-short" style="display: inline;"> The KM2A is the largest sub-array of the Large High Altitude Air Shower Observatory (LHAASO). It consists of 5216 electromagnetic particle detectors (EDs) and 1188 muon detectors (MDs). The data recorded by the EDs and MDs are used to reconstruct primary information of cosmic ray and gamma-ray showers. This information is used for physical analysis in gamma-ray astronomy and cosmic ray physics. To… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.11826v3-abstract-full').style.display = 'inline'; document.getElementById('2405.11826v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.11826v3-abstract-full" style="display: none;"> The KM2A is the largest sub-array of the Large High Altitude Air Shower Observatory (LHAASO). It consists of 5216 electromagnetic particle detectors (EDs) and 1188 muon detectors (MDs). The data recorded by the EDs and MDs are used to reconstruct primary information of cosmic ray and gamma-ray showers. This information is used for physical analysis in gamma-ray astronomy and cosmic ray physics. To ensure the reliability of the LHAASO-KM2A data, a three-level quality control system has been established. It is used to monitor the status of detector units, stability of reconstructed parameters and the performance of the array based on observations of the Crab Nebula and Moon shadow. This paper will introduce the control system and its application on the LHAASO-KM2A data collected from August 2021 to July 2023. During this period, the pointing and angular resolution of the array were stable. From the observations of the Moon shadow and Crab Nebula, the results achieved using the two methods are consistent with each other. According to the observation of the Crab Nebula at energies from 25 TeV to 100 TeV, the time averaged pointing errors are estimated to be $-0.003^{\circ} \pm 0.005^{\circ}$ and $0.001^{\circ} \pm 0.006^{\circ}$ in the R.A. and Dec directions, respectively. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.11826v3-abstract-full').style.display = 'none'; document.getElementById('2405.11826v3-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 9 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.07691">arXiv:2405.07691</a> <span> [<a href="https://arxiv.org/pdf/2405.07691">pdf</a>, <a href="https://arxiv.org/format/2405.07691">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ad5e6d">10.3847/2041-8213/ad5e6d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery of Very-high-energy Gamma-ray Emissions from the Low Luminosity AGN NGC 4278 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=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="2405.07691v1-abstract-short" style="display: inline;"> The first source catalog of Large High Altitude Air Shower Observatory reported the detection of a very-high-energy gamma ray source, 1LHAASO J1219+2915. In this paper a further detailed study of the spectral and temporal behavior of this point-like source have been carried. The best-fit position of the TeV source ($\rm{RA}=185.05^{\circ}\pm0.04^{\circ}$, $\rm{Dec}=29.25^{\circ}\pm0.03^{\circ}$) i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.07691v1-abstract-full').style.display = 'inline'; document.getElementById('2405.07691v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.07691v1-abstract-full" style="display: none;"> The first source catalog of Large High Altitude Air Shower Observatory reported the detection of a very-high-energy gamma ray source, 1LHAASO J1219+2915. In this paper a further detailed study of the spectral and temporal behavior of this point-like source have been carried. The best-fit position of the TeV source ($\rm{RA}=185.05^{\circ}\pm0.04^{\circ}$, $\rm{Dec}=29.25^{\circ}\pm0.03^{\circ}$) is compatible with NGC 4278 within $\sim0.03$ degree. Variation analysis shows an indication of the variability at a few months level in the TeV band, which is consistent with low frequency observations. Based on these observations, we report the detection of TeV $纬$-ray emissions from this low-luminosity AGN NGC 4278. The observations by LHAASO-WCDA during active period has a significance level of 8.8\,$蟽$ with best-fit photon spectral index $\varGamma=2.56\pm0.14$ and a flux $f_{1-10\,\rm{TeV}}=(7.0\pm1.1_{\rm{sta}}\pm0.35_{\rm{syst}})\times10^{-13}\,\rm{photons\,cm^{-2}\,s^{-1}}$, or approximately $5\%$ of the Crab Nebula. The discovery of VHE from NGC 4278 indicates that the compact, weak radio jet can efficiently accelerate particles and emit TeV photons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.07691v1-abstract-full').style.display = 'none'; document.getElementById('2405.07691v1-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 5 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.05557">arXiv:2404.05557</a> <span> [<a href="https://arxiv.org/pdf/2404.05557">pdf</a>, <a href="https://arxiv.org/format/2404.05557">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"> Origin and Properties of the Near Subsonic Solar Wind Observed by Parker Solar Probe </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+W">Wenshuai Cheng</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Y+D">Ying D. Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Ran%2C+H">Hao Ran</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yiming Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Stevens%2C+M+L">Michael L. Stevens</a>, <a href="/search/astro-ph?searchtype=author&query=Kasper%2C+J+C">Justin C. Kasper</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.05557v3-abstract-short" style="display: inline;"> We identify and examine the solar wind intervals near the sonic critical point (i.e., $M_S \sim 1$) observed by the Parker Solar Probe (PSP). The near subsonic wind intervals show similar properties: a low density, an extremely low velocity, a low proton temperature, and essentially no magnetic field deflections compared with the surrounding solar wind. The extremely low velocity is the primary co… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.05557v3-abstract-full').style.display = 'inline'; document.getElementById('2404.05557v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.05557v3-abstract-full" style="display: none;"> We identify and examine the solar wind intervals near the sonic critical point (i.e., $M_S \sim 1$) observed by the Parker Solar Probe (PSP). The near subsonic wind intervals show similar properties: a low density, an extremely low velocity, a low proton temperature, and essentially no magnetic field deflections compared with the surrounding solar wind. The extremely low velocity is the primary contributor to the near crossing of the sonic critical point rather than the sound speed, which is roughly constant in these intervals. Source tracing with a potential field source surface (PFSS) model suggests that the near subsonic intervals all connect to the boundaries inside coronal holes. Heliospheric current sheet (HCS) and partial HCS crossings around the near subsonic intervals indicate that the near subsonic wind is a transition layer between the slow and fast wind. The above scenario is consistent with the nature of the near subsonic wind as a low Mach-number boundary layer (LMBL), which facilitates the crossing of the sonic critical point at 15-20 $R_S$. Moreover, we find a dependence of the amplitude of switchbacks on the radial sonic Mach number. Magnetic field deflections essentially disappear near the sonic critical point, which suggests that switchbacks originate from above the sonic critical point. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.05557v3-abstract-full').style.display = 'none'; document.getElementById('2404.05557v3-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">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/2404.04801">arXiv:2404.04801</a> <span> [<a href="https://arxiv.org/pdf/2404.04801">pdf</a>, <a href="https://arxiv.org/ps/2404.04801">ps</a>, <a href="https://arxiv.org/format/2404.04801">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/10.1007/s41605-024-00467-8">10.1007/s41605-024-00467-8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> LHAASO-KM2A detector simulation using Geant4 </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. (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="2404.04801v1-abstract-short" style="display: inline;"> KM2A is one of the main sub-arrays of LHAASO, working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV. Detector simulation is the important foundation for estimating detector performance and data analysis. It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units (>6000) with… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.04801v1-abstract-full').style.display = 'inline'; document.getElementById('2404.04801v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.04801v1-abstract-full" style="display: none;"> KM2A is one of the main sub-arrays of LHAASO, working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV. Detector simulation is the important foundation for estimating detector performance and data analysis. It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units (>6000) with large altitude difference (30 m) and huge coverage (1.3 km^2). In this paper, the design of the KM2A simulation code G4KM2A based on Geant4 is introduced. The process of G4KM2A is optimized mainly in memory consumption to avoid memory overffow. Some simpliffcations are used to signiffcantly speed up the execution of G4KM2A. The running time is reduced by at least 30 times compared to full detector simulation. The particle distributions and the core/angle resolution comparison between simulation and experimental data of the full KM2A array are also presented, which show good agreement. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.04801v1-abstract-full').style.display = 'none'; document.getElementById('2404.04801v1-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.10010">arXiv:2403.10010</a> <span> [<a href="https://arxiv.org/pdf/2403.10010">pdf</a>, <a href="https://arxiv.org/format/2403.10010">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.132.131002">10.1103/PhysRevLett.132.131002 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=The+LHAASO+Collaboration"> The LHAASO Collaboration</a>, <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%2C+A">A. 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> , et al. (256 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.10010v2-abstract-short" style="display: inline;"> We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.10010v2-abstract-full').style.display = 'inline'; document.getElementById('2403.10010v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.10010v2-abstract-full" style="display: none;"> We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at $3.67 \pm 0.05 \pm 0.15$ PeV. Below the knee, the spectral index is found to be -$2.7413 \pm 0.0004 \pm 0.0050$, while above the knee, it is -$3.128 \pm 0.005 \pm 0.027$, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -$0.1200 \pm 0.0003 \pm 0.0341$. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.10010v2-abstract-full').style.display = 'none'; document.getElementById('2403.10010v2-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 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review Letters 132, 131002 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.15654">arXiv:2401.15654</a> <span> [<a href="https://arxiv.org/pdf/2401.15654">pdf</a>, <a href="https://arxiv.org/ps/2401.15654">ps</a>, <a href="https://arxiv.org/format/2401.15654">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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 Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</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/10.1140/epjc/s10052-024-12856-w">10.1140/epjc/s10052-024-12856-w <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Accretion of matter by a Charged dilaton black hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yinan Jia</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+T">Tong-Yu He</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+W">Wen-Qian Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Han%2C+Z">Zhan-Wen Han</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+R">Rong-Jia 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="2401.15654v2-abstract-short" style="display: inline;"> Considering accretion onto a charged dilaton black hole, the fundamental equations governing accretion, general analytic expressions for critical points, critical velocity, critical speed of sound, and ultimately the mass accretion rate are obtained. A new constraint on the dilation parameter coming from string theory is found and the case for polytropic gas is delved into a detailed discussion. I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.15654v2-abstract-full').style.display = 'inline'; document.getElementById('2401.15654v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.15654v2-abstract-full" style="display: none;"> Considering accretion onto a charged dilaton black hole, the fundamental equations governing accretion, general analytic expressions for critical points, critical velocity, critical speed of sound, and ultimately the mass accretion rate are obtained. A new constraint on the dilation parameter coming from string theory is found and the case for polytropic gas is delved into a detailed discussion. It is found that the dialtion and the adiabatic index of accreted material have deep effects on the accretion process. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.15654v2-abstract-full').style.display = 'none'; document.getElementById('2401.15654v2-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Eur.Phys.J.C 84 (2024) 5, 501 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.15622">arXiv:2311.15622</a> <span> [<a href="https://arxiv.org/pdf/2311.15622">pdf</a>, <a href="https://arxiv.org/format/2311.15622">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"> Properties of Steady Sub-Alfv茅nic Solar Wind in Comparison with Super-Alfv茅nic Wind from Measurements of Parker Solar Probe </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yiming Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Y+D">Ying D. Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Ran%2C+H">Hao Ran</a>, <a href="/search/astro-ph?searchtype=author&query=Cheng%2C+W">Wenshuai Cheng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.15622v3-abstract-short" style="display: inline;"> We identify more than ten steady sub-Alfv茅nic solar wind intervals from the measurements of the Parker Solar Probe (PSP) from encounter 8 to encounter 14. An analysis of these sub-Alfv茅nic intervals reveals similar properties and similar origins. In situ measurements show that these intervals feature a decreased radial Alfv茅n Mach number resulting from a reduced density and a relatively low veloci… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.15622v3-abstract-full').style.display = 'inline'; document.getElementById('2311.15622v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.15622v3-abstract-full" style="display: none;"> We identify more than ten steady sub-Alfv茅nic solar wind intervals from the measurements of the Parker Solar Probe (PSP) from encounter 8 to encounter 14. An analysis of these sub-Alfv茅nic intervals reveals similar properties and similar origins. In situ measurements show that these intervals feature a decreased radial Alfv茅n Mach number resulting from a reduced density and a relatively low velocity, and that switchbacks are suppressed in these intervals. Magnetic source tracing indicates that these sub-Alfv茅nic streams generally originate from the boundaries inside coronal holes, or narrow/small regions of open magnetic fields. Such properties and origins suggest that these streams are low Mach-number boundary layers (LMBLs), which is a special component of the pristine solar wind proposed by Liu et al. We find that the LMBL wind, the fast wind from deep inside coronal holes, and the slow streamer wind constitute three typical components of the young solar wind near the Sun. In these sub-Alfv茅nic intervals, the Alfv茅n radius varies between 15 and 25 solar radii, in contrast with a typical 12 radii for the Alfv茅n radius of the super-Alfv茅nic wind. These results give a self-consistent picture interpreting the PSP measurements in the vicinity of the Sun. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.15622v3-abstract-full').style.display = 'none'; document.getElementById('2311.15622v3-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication 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/2311.05677">arXiv:2311.05677</a> <span> [<a href="https://arxiv.org/pdf/2311.05677">pdf</a>, <a href="https://arxiv.org/format/2311.05677">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> </div> <p class="title is-5 mathjax"> The accretion history of the Milky Way. II. Internal kinematics of globular clusters and of dwarf galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jianling Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Mamon%2C+G+A">Gary A. Mamon</a>, <a href="/search/astro-ph?searchtype=author&query=Pawlowski%2C+M+S">Marcel S. Pawlowski</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+H">Hefan Li</a>, <a href="/search/astro-ph?searchtype=author&query=Bonifacio%2C+P">Piercarlo Bonifacio</a>, <a href="/search/astro-ph?searchtype=author&query=Caffau%2C+E">Elisabetta Caffau</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H">Haifeng 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="2311.05677v4-abstract-short" style="display: inline;"> We study how structural properties of globular clusters and dwarf galaxies are linked to their orbits in the Milky Way halo. From the inner to the outer halo, orbital energy increases and stellar-systems gradually move out of internal equilibrium: in the inner halo, high-surface brightness globular clusters are at pseudo-equilibrium, while further away, low-surface brightness clusters and dwarfs a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.05677v4-abstract-full').style.display = 'inline'; document.getElementById('2311.05677v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.05677v4-abstract-full" style="display: none;"> We study how structural properties of globular clusters and dwarf galaxies are linked to their orbits in the Milky Way halo. From the inner to the outer halo, orbital energy increases and stellar-systems gradually move out of internal equilibrium: in the inner halo, high-surface brightness globular clusters are at pseudo-equilibrium, while further away, low-surface brightness clusters and dwarfs appear more tidally disturbed. Dwarf galaxies are the latest to arrive into the halo as indicated by their large orbital energies and pericenters, and have no time for more than one orbit. Their (gas-rich) progenitors likely lost their gas during their recent arrival in the Galactic halo. If dwarfs are at equilibrium with their dark matter (DM) content, the DM density should anti-correlate with pericenter. However, the transformation of DM dominated dwarfs from gas-rich rotation-supported into gas-poor dispersion-supported systems is unlikely accomplished during a single orbit. We suggest instead that the above anti-correlation is brought by the combination of ram-pressure stripping and of Galactic tidal shocks. Recent gas removal leads to an expansion of their stellar content caused by the associated gravity loss, making them sufficiently fragile to be transformed near pericenter passage. Out of equilibrium dwarfs would explain the observed anti-correlation of kinematics-based DM density with pericenter without invoking DM density itself, questioning its previous estimates. Ram-pressure stripping and tidal shocks may contribute to the dwarf velocity dispersion excess. It predicts the presence of numerous stars in their outskirts and a few young stars in their cores. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.05677v4-abstract-full').style.display = 'none'; document.getElementById('2311.05677v4-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 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Paper II, 18 pages, 15 Figures, MNRAS 527, 2178-2733 (2024), see also paper III with simulations (arXiv:2311.05687), as well as a video showing the transformation of a dwarf recently falling into the MW halo at: https://www.youtube.com/watch?v=SwxSdmfQis4</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.17082">arXiv:2310.17082</a> <span> [<a href="https://arxiv.org/pdf/2310.17082">pdf</a>, <a href="https://arxiv.org/ps/2310.17082">ps</a>, <a href="https://arxiv.org/format/2310.17082">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"> Does or did the supernova remnant Cassiopeia A operate as a PeVatron? </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="2310.17082v1-abstract-short" style="display: inline;"> For decades, supernova remnants (SNRs) have been considered the prime sources of Galactic Cosmic rays (CRs). But whether SNRs can accelerate CR protons to PeV energies and thus dominate CR flux up to the knee is currently under intensive theoretical and phenomenological debate. The direct test of the ability of SNRs to operate as CR PeVatrons can be provided by ultrahigh-energy (UHE;… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.17082v1-abstract-full').style.display = 'inline'; document.getElementById('2310.17082v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.17082v1-abstract-full" style="display: none;"> For decades, supernova remnants (SNRs) have been considered the prime sources of Galactic Cosmic rays (CRs). But whether SNRs can accelerate CR protons to PeV energies and thus dominate CR flux up to the knee is currently under intensive theoretical and phenomenological debate. The direct test of the ability of SNRs to operate as CR PeVatrons can be provided by ultrahigh-energy (UHE; $E_纬\geq 100$~TeV) $纬$-rays. In this context, the historical SNR Cassiopeia A (Cas A) is considered one of the most promising target for UHE observations. This paper presents the observation of Cas A and its vicinity by the LHAASO KM2A detector. The exceptional sensitivity of LHAASO KM2A in the UHE band, combined with the young age of Cas A, enabled us to derive stringent model-independent limits on the energy budget of UHE protons and nuclei accelerated by Cas A at any epoch after the explosion. The results challenge the prevailing paradigm that Cas A-type SNRs are major suppliers of PeV CRs in the Milky Way. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.17082v1-abstract-full').style.display = 'none'; document.getElementById('2310.17082v1-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 3 figures, Accepted by the 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/2310.08845">arXiv:2310.08845</a> <span> [<a href="https://arxiv.org/pdf/2310.08845">pdf</a>, <a href="https://arxiv.org/format/2310.08845">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1126/sciadv.adj2778">10.1126/sciadv.adj2778 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Very high energy gamma-ray emission beyond 10 TeV from GRB 221009A </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%2C+A">A. 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="2310.08845v2-abstract-short" style="display: inline;"> The highest energy gamma-rays from gamma-ray bursts (GRBs) have important implications for their radiation mechanism. Here we report for the first time the detection of gamma-rays up to 13 TeV from the brightest GRB 221009A by the Large High Altitude Air-shower Observatory (LHAASO). The LHAASO-KM2A detector registered more than 140 gamma-rays with energies above 3 TeV during 230$-$900s after the t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.08845v2-abstract-full').style.display = 'inline'; document.getElementById('2310.08845v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.08845v2-abstract-full" style="display: none;"> The highest energy gamma-rays from gamma-ray bursts (GRBs) have important implications for their radiation mechanism. Here we report for the first time the detection of gamma-rays up to 13 TeV from the brightest GRB 221009A by the Large High Altitude Air-shower Observatory (LHAASO). The LHAASO-KM2A detector registered more than 140 gamma-rays with energies above 3 TeV during 230$-$900s after the trigger. The intrinsic energy spectrum of gamma-rays can be described by a power-law after correcting for extragalactic background light (EBL) absorption. Such a hard spectrum challenges the synchrotron self-Compton (SSC) scenario of relativistic electrons for the afterglow emission above several TeV. Observations of gamma-rays up to 13 TeV from a source with a measured redshift of z=0.151 hints more transparency in intergalactic space than previously expected. Alternatively, one may invoke new physics such as Lorentz Invariance Violation (LIV) or an axion origin of very high energy (VHE) signals. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.08845v2-abstract-full').style.display = 'none'; document.getElementById('2310.08845v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">49pages, 11figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science Advances, 9, eadj2778 (2023) 15 November 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.00048">arXiv:2309.00048</a> <span> [<a href="https://arxiv.org/pdf/2309.00048">pdf</a>, <a href="https://arxiv.org/format/2309.00048">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</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/10.1051/0004-6361/202347513">10.1051/0004-6361/202347513 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detection of the Keplerian decline in the Milky Way rotation curve </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H">Haifeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jianling Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Amram%2C+P">Philippe Amram</a>, <a href="/search/astro-ph?searchtype=author&query=Chemin%2C+L">Laurent Chemin</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin 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="2309.00048v4-abstract-short" style="display: inline;"> Our position inside the Galactic disc had prevented us from establishing an accurate rotation curve, until the advent of Gaia, whose third data release (Gaia DR3) made it possible to specify it up to twice the optical radius. We aim to establish a new rotation curve of the Galaxy from the Gaia DR3, by drastically reducing uncertainties and systematics, and with the goal to provide a new estimate o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.00048v4-abstract-full').style.display = 'inline'; document.getElementById('2309.00048v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.00048v4-abstract-full" style="display: none;"> Our position inside the Galactic disc had prevented us from establishing an accurate rotation curve, until the advent of Gaia, whose third data release (Gaia DR3) made it possible to specify it up to twice the optical radius. We aim to establish a new rotation curve of the Galaxy from the Gaia DR3, by drastically reducing uncertainties and systematics, and with the goal to provide a new estimate of the mass of the Galaxy. We have compared different estimates, established a robust assessment of the systematic uncertainties, and addressed differences in methodologies, particularly regarding distance estimates. This results in a sharply decreasing rotation curve for the Milky Way, the decrease in velocity between 19.5 and 26.5 kpc is approximately 30 km s$^{-1}$. We have identified, for the first time, a Keplerian decline of the rotation curve, starting at $\sim$ 19 kpc and up to $\sim$ 26.5 kpc from the Galaxy center, while a flat rotation curve is rejected with a significance of 3$蟽$. The total mass is revised downwards to $2.06^{+0.24}_{-0.13}\times 10^{11}\ M_{\odot}$, in agreement with an absence of significant mass increase at radii larger than 19 kpc. The upper limit of the total mass was evaluated by considering the upper values of velocity measurements, which leads to a strict, unsurpassable, limit of $5.4\times 10^{11}\ M_{\odot}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.00048v4-abstract-full').style.display = 'none'; document.getElementById('2309.00048v4-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 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 Pages, 13 Figures, version compliant to that of Astronomy and Astrophysics journal</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 678, A208 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.13781">arXiv:2308.13781</a> <span> [<a href="https://arxiv.org/pdf/2308.13781">pdf</a>, <a href="https://arxiv.org/format/2308.13781">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/acebce">10.3847/1538-4357/acebce <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of gamma rays up to 320 TeV from the middle-aged TeV pulsar wind nebula HESS J1849$-$000 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Amenomori%2C+M">M. Amenomori</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+S">S. Asano</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=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D">D. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W+Y">W. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cirennima"> Cirennima</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+L+K">L. K. Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+J+H">J. H. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+K">K. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z+Y">Z. Y. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Q">Qi Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gomi%2C+A">A. Gomi</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Y">Y. Y. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Hayashi%2C+Y">Y. Hayashi</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a> , et al. (93 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="2308.13781v1-abstract-short" style="display: inline;"> Gamma rays from HESS J1849$-$000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches $4.0\, 蟽$ and $4.4\, 蟽$ levels above 25 TeV and 100 TeV, respectively, in units of Gaussian standard deviation $蟽$. The energy spectrum measured between $40\, {\rm TeV} < E < 320\, {\rm TeV}$ for the f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13781v1-abstract-full').style.display = 'inline'; document.getElementById('2308.13781v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.13781v1-abstract-full" style="display: none;"> Gamma rays from HESS J1849$-$000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches $4.0\, 蟽$ and $4.4\, 蟽$ levels above 25 TeV and 100 TeV, respectively, in units of Gaussian standard deviation $蟽$. The energy spectrum measured between $40\, {\rm TeV} < E < 320\, {\rm TeV}$ for the first time is described with a simple power-law function of ${\rm d}N/{\rm d}E = (2.86 \pm 1.44) \times 10^{-16}(E/40\, {\rm TeV})^{-2.24 \pm 0.41}\, {\rm TeV}^{-1}\, {\rm cm}^{-2}\, {\rm s}^{-1}$. The gamma-ray energy spectrum from the sub-TeV ($E < 1\, {\rm TeV}$) to sub-PeV ($100\, {\rm TeV} < E < 1\, {\rm PeV}$) ranges including the results of previous studies can be modeled with the leptonic scenario, inverse Compton scattering by high-energy electrons accelerated by the PWN of PSR J1849$-$0001. On the other hand, the gamma-ray energy spectrum can also be modeled with the hadronic scenario in which gamma rays are generated from the decay of neutral pions produced by collisions between accelerated cosmic-ray protons and the ambient molecular cloud found in the gamma-ray emitting region. The cutoff energy of cosmic-ray protons $E_{\rm p\, cut}$, cut is estimated at ${\rm log}_{10}(E_{\rm p,\, cut}/{\rm TeV}) = 3.73^{+2.98}_{-0.66}$, suggesting that protons are accelerated up to the PeV energy range. Our study thus proposes that HESS J1849$-$000 should be further investigated as a new candidate for a Galactic PeV cosmic-ray accelerator, PeVatron. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13781v1-abstract-full').style.display = 'none'; document.getElementById('2308.13781v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 2 figures, Accepted for publication from the Astrophysical Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.13780">arXiv:2308.13780</a> <span> [<a href="https://arxiv.org/pdf/2308.13780">pdf</a>, <a href="https://arxiv.org/format/2308.13780">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ac6ef4">10.3847/1538-4357/ac6ef4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurement of the Gamma-Ray Energy Spectrum beyond 100 TeV from the HESS J1843$-$033 Region </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Amenomori%2C+M">M. Amenomori</a>, <a href="/search/astro-ph?searchtype=author&query=Asano%2C+S">S. Asano</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=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D">D. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W+Y">W. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cirennima"> Cirennima</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+L+K">L. K. Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+J+H">J. H. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+K">K. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z+Y">Z. Y. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Q">Qi Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gomi%2C+A">A. Gomi</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Y">Y. Y. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+Z+T">Z. T. He</a> , et al. (91 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="2308.13780v1-abstract-short" style="display: inline;"> HESS J1843$-$033 is a very-high-energy gamma-ray source whose origin remains unidentified. This work presents, for the first time, the energy spectrum of gamma rays beyond $100\, {\rm TeV}$ from the HESS J1843$-$033 region using the data recorded by the Tibet air shower array and its underground muon detector array. A gamma-ray source with an extension of $0.34^{\circ} \pm 0.12^{\circ}$ is success… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13780v1-abstract-full').style.display = 'inline'; document.getElementById('2308.13780v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.13780v1-abstract-full" style="display: none;"> HESS J1843$-$033 is a very-high-energy gamma-ray source whose origin remains unidentified. This work presents, for the first time, the energy spectrum of gamma rays beyond $100\, {\rm TeV}$ from the HESS J1843$-$033 region using the data recorded by the Tibet air shower array and its underground muon detector array. A gamma-ray source with an extension of $0.34^{\circ} \pm 0.12^{\circ}$ is successfully detected above $25\, {\rm TeV}$ at $(伪,\, 未) = (281.09^{\circ}\pm 0.10^{\circ},\, -3.76^{\circ}\pm 0.09^{\circ})$ near HESS J1843$-$033 with a statistical significance of $6.2\, 蟽$, and the source is named TASG J1844$-$038. The position of TASG J1844$-$038 is consistent with those of HESS J1843$-$033, eHWC J1842$-$035, and LHAASO J1843$-$0338. The measured gamma-ray energy spectrum in $25\, {\rm TeV} < E < 130\, {\rm TeV}$ is described with ${\rm d}N/{\rm d}E = (9.70\pm 1.89)\times 10^{-16} (E/40\, {\rm TeV})^{-3.26\pm 0.30}\, {\rm TeV}^{-1} {\rm cm}^{-2} {\rm s}^{-1}$, and the spectral fit to the combined spectra of HESS J1843$-$033, LHAASO J1843$-$0338, and TASG J1844$-$038 implies the existence of a cutoff at $49.5\pm 9.0\, {\rm TeV}$. Associations of TASG J1844-038 with SNR G28.6$-$0.1 and PSR J1844-0346 are also discussed in detail for the first time. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13780v1-abstract-full').style.display = 'none'; document.getElementById('2308.13780v1-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 4 figures, 1 table</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.07993">arXiv:2307.07993</a> <span> [<a href="https://arxiv.org/pdf/2307.07993">pdf</a>, <a href="https://arxiv.org/format/2307.07993">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"> Identifying symbiotic stars with machine learning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yongle Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+S">Sufen Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+C">Chunhua Zhu</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+L">Lin Li</a>, <a href="/search/astro-ph?searchtype=author&query=Ma%2C+M">Mei Ma</a>, <a href="/search/astro-ph?searchtype=author&query=Lv%2C+G">Guoliang Lv</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.07993v2-abstract-short" style="display: inline;"> Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by theoretical models. To bridge this gap, this study ut… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.07993v2-abstract-full').style.display = 'inline'; document.getElementById('2307.07993v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.07993v2-abstract-full" style="display: none;"> Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by theoretical models. To bridge this gap, this study utilized machine learning techniques to efficiently identify new symbiotic stars candidates. Three algorithms (XGBoost, LightGBM, and Decision Tree) were applied to a dataset of 198 confirmed symbiotic stars and the resulting model was then used to analyze data from the LAMOST survey, leading to the identification of 11,709 potential symbiotic stars candidates. Out of the these potential symbiotic stars candidates listed in the catalog, 15 have spectra available in the SDSS survey. Among these 15 candidates, two candidates, namely V* V603 Ori and V* GN Tau, have been confirmed as symbiotic stars. The remaining 11 candidates have been classified as accreting-only symbiotic star candidates. The other two candidates, one of which has been identified as a galaxy by both SDSS and LAMOST surveys, and the other identified as a quasar by SDSS survey and as a galaxy by LAMOST survey. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.07993v2-abstract-full').style.display = 'none'; document.getElementById('2307.07993v2-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 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 6 figures, accepted 11-Jul-2023 by RAA</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.05461">arXiv:2306.05461</a> <span> [<a href="https://arxiv.org/pdf/2306.05461">pdf</a>, <a href="https://arxiv.org/format/2306.05461">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 mass estimates of the Milky Way </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H">Haifeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jianling Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin 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="2306.05461v1-abstract-short" style="display: inline;"> We use the rotation curve from Gaia data release (DR) 3 to estimate the mass of the Milky Way. We consider an Einasto density profile to model the dark matter component. We extrapolate and obtain a dynamical mass $M=2.75^{+3.11}_{-0.48}\times 10^{11} M_\odot$ at $112$ kpc. This lower-mass Milky Way is consistent with the significant declining rotation curve, and can provide new insights into our G… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05461v1-abstract-full').style.display = 'inline'; document.getElementById('2306.05461v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.05461v1-abstract-full" style="display: none;"> We use the rotation curve from Gaia data release (DR) 3 to estimate the mass of the Milky Way. We consider an Einasto density profile to model the dark matter component. We extrapolate and obtain a dynamical mass $M=2.75^{+3.11}_{-0.48}\times 10^{11} M_\odot$ at $112$ kpc. This lower-mass Milky Way is consistent with the significant declining rotation curve, and can provide new insights into our Galaxy and halo inhabitants. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05461v1-abstract-full').style.display = 'none'; document.getElementById('2306.05461v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 2 figures, Accepted for publication in proceedings of IAU Symposium 379: Dynamical Masses of Local Group Galaxies, Potsdam, March 20-24, 2023</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.17030">arXiv:2305.17030</a> <span> [<a href="https://arxiv.org/pdf/2305.17030">pdf</a>, <a href="https://arxiv.org/format/2305.17030">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> <div 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/10.3847/1538-4365/acfd29">10.3847/1538-4365/acfd29 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The First LHAASO Catalog of Gamma-Ray Sources </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="2305.17030v2-abstract-short" style="display: inline;"> We present the first catalog of very-high energy and ultra-high energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory (LHAASO). The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array (WCDA) from March 2021 to September 2022 and 933 days of data recorded by the Kilometer Squared Array (KM2A) from January 2020 to September 2022.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.17030v2-abstract-full').style.display = 'inline'; document.getElementById('2305.17030v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.17030v2-abstract-full" style="display: none;"> We present the first catalog of very-high energy and ultra-high energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory (LHAASO). The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array (WCDA) from March 2021 to September 2022 and 933 days of data recorded by the Kilometer Squared Array (KM2A) from January 2020 to September 2022. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering declination from $-$20$^{\circ}$ to 80$^{\circ}$. In total, the catalog contains 90 sources with an extended size smaller than $2^\circ$ and a significance of detection at $> 5蟽$. Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ($E > 100$ TeV) emission at $> 4蟽$ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.17030v2-abstract-full').style.display = 'none'; document.getElementById('2305.17030v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">40 pages, 13 figures, 4 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Supplement Series, 271 (2024) 25 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.05372">arXiv:2305.05372</a> <span> [<a href="https://arxiv.org/pdf/2305.05372">pdf</a>, <a href="https://arxiv.org/format/2305.05372">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.131.151001">10.1103/PhysRevLett.131.151001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurement of ultra-high-energy diffuse gamma-ray emission of the Galactic plane from 10 TeV to 1 PeV with LHAASO-KM2A </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="2305.05372v2-abstract-short" style="display: inline;"> The diffuse Galactic $纬$-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this work we report the measurements of diffuse $纬$-rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer ar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.05372v2-abstract-full').style.display = 'inline'; document.getElementById('2305.05372v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.05372v2-abstract-full" style="display: none;"> The diffuse Galactic $纬$-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this work we report the measurements of diffuse $纬$-rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner ($15^{\circ}<l<125^{\circ}$, $|b|<5^{\circ}$) and outer ($125^{\circ}<l<235^{\circ}$, $|b|<5^{\circ}$) Galactic plane are detected with $29.1蟽$ and $12.7蟽$ significance, respectively. The outer Galactic plane diffuse emission is detected for the first time in the very- to ultra-high-energy domain ($E>10$~TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of $-2.99\pm0.04$, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of $\sim3$ than the prediction. A similar spectrum with an index of $-2.99\pm0.07$ is found in the outer Galaxy region, and the absolute flux for $10\lesssim E\lesssim60$ TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.05372v2-abstract-full').style.display = 'none'; document.getElementById('2305.05372v2-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 8 figures, 5 tables; accepted for publication in Physical Review Letters; source mask file provided as ancillary file</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 131, 151001 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.05220">arXiv:2304.05220</a> <span> [<a href="https://arxiv.org/pdf/2304.05220">pdf</a>, <a href="https://arxiv.org/format/2304.05220">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> </div> </div> <p class="title is-5 mathjax"> Solving the domain wall problem with first-order phase transition </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Li%2C+Y">Yang Li</a>, <a href="/search/astro-ph?searchtype=author&query=Bian%2C+L">Ligong Bian</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yongtao Jia</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.05220v1-abstract-short" style="display: inline;"> Domain wall networks are two-dimensional topological defects generally predicted in many beyond standard model physics. In this Letter, we propose to solve the domain wall problem with the first-order phase transition. We numerically study the phase transition dynamics, and for the first time show that the domain walls reached scaling regime can be diluted through the interaction with vacuum bubbl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.05220v1-abstract-full').style.display = 'inline'; document.getElementById('2304.05220v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.05220v1-abstract-full" style="display: none;"> Domain wall networks are two-dimensional topological defects generally predicted in many beyond standard model physics. In this Letter, we propose to solve the domain wall problem with the first-order phase transition. We numerically study the phase transition dynamics, and for the first time show that the domain walls reached scaling regime can be diluted through the interaction with vacuum bubbles during the first-order phase transition. We find that the amplitude of the gravitational waves produced by the second-stage first-order phase transition is several orders higher than that from the domain walls evolution in the scaling regime. The scale of the first-order phase transition that dilute the domain walls can be probed through gravitational waves detection. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.05220v1-abstract-full').style.display = 'none'; document.getElementById('2304.05220v1-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6+7 pages, 6+6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.08519">arXiv:2212.08519</a> <span> [<a href="https://arxiv.org/pdf/2212.08519">pdf</a>, <a href="https://arxiv.org/format/2212.08519">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142977">10.1051/0004-6361/202142977 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Investigating the vertical distribution of the disk as a function of radial action </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yunpeng Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Yuqin Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Du%2C+C">Cuihua Du</a>, <a href="/search/astro-ph?searchtype=author&query=zhao%2C+G">Gang zhao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2212.08519v1-abstract-short" style="display: inline;"> As heating processes can broaden the distributions of radial actions and the vertical distributions of the Galactic disks, we investigate the vertical distribution of the Galactic disks as a function of radial action based on Apache Point Observatory Galactic Evolution Experiment(APOGEE) and Gaia data in order to deepen our understanding of the formation and heating history of the Galactic disks.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.08519v1-abstract-full').style.display = 'inline'; document.getElementById('2212.08519v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.08519v1-abstract-full" style="display: none;"> As heating processes can broaden the distributions of radial actions and the vertical distributions of the Galactic disks, we investigate the vertical distribution of the Galactic disks as a function of radial action based on Apache Point Observatory Galactic Evolution Experiment(APOGEE) and Gaia data in order to deepen our understanding of the formation and heating history of the Galactic disks. We find that the distributions of radial action for both the thin and thick disks can be approximately described by pseudo-isothermal distributions, which give a statistical measurement for the temperature of the disk as indicated by the mean radial action of the star sample. Estimations of the scale heights in different radial action ranges for these pseudo-isothermal distributions of the disks seem to show fixed relationships between radial action $J_R$ and scale height $h$. We describe these relationships with a two-parameter function of $h = \sqrt{J_R /a} + b$, where $a$ and $b$ are free parameters. When testing with a three-parameter function of $h=\sqrt[伪]{J_R/a}+b$, we find that this two-parameter function describes the thin disk well, but we note the function should be used with care for the thick disk. When comparing the best-fit relationships between the inner and outer disk for both of the thin and thick disks, we find that the relationships are nearly the same for the thin disks but are different for the thick disks. The inner thick disk shows a nearly flattened relationship, while the outer thick disk presents a gradually increasing relationship. This work highlights an alternative way to unveil the heating history of the disks by investigating the relationship between scale height and radial action, as these relationships encode the formation and heating history of the Galactic disks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.08519v1-abstract-full').style.display = 'none'; document.getElementById('2212.08519v1-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 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 10 figures, accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 669, A107 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.07441">arXiv:2212.07441</a> <span> [<a href="https://arxiv.org/pdf/2212.07441">pdf</a>, <a href="https://arxiv.org/format/2212.07441">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac3758">10.1093/mnras/stac3758 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The accretion history of the Milky Way. I. How it shapes globular clusters and dwarf galaxies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+H">Hefan Li</a>, <a href="/search/astro-ph?searchtype=author&query=Mamon%2C+G+A">Gary A. Mamon</a>, <a href="/search/astro-ph?searchtype=author&query=Pawlowski%2C+M+S">Marcel S. Pawlowski</a>, <a href="/search/astro-ph?searchtype=author&query=Bonifacio%2C+P">Piercarlo Bonifacio</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+H">Haifeng Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jianling Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin 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="2212.07441v4-abstract-short" style="display: inline;"> Halo inhabitants are individual stars, stellar streams, star and globular clusters, and dwarf galaxies. Here we compare the two last categories that include objects of similar stellar mass, which are often studied as self-dynamical equilibrium systems. We discover that the half-light radius of globular clusters depends on their orbital pericenter and total energy, and that Milky Way (MW) tides may… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.07441v4-abstract-full').style.display = 'inline'; document.getElementById('2212.07441v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.07441v4-abstract-full" style="display: none;"> Halo inhabitants are individual stars, stellar streams, star and globular clusters, and dwarf galaxies. Here we compare the two last categories that include objects of similar stellar mass, which are often studied as self-dynamical equilibrium systems. We discover that the half-light radius of globular clusters depends on their orbital pericenter and total energy, and that Milky Way (MW) tides may explain the observed correlation. We also suggest that the accretion epoch of stellar systems in the MW halo can be calibrated by the total orbital energy, and that such a relation is due to both the mass growth of the MW and dynamical friction affecting mostly satellites with numerous orbits. This calibration starts from the bulge, to Kraken, Gaia Sausage Enceladus, Sagittarius stellar systems, and finally to the new coming dwarfs, either or not linked to the vast-polar structure. The most eccentric globular clusters and dwarfs have their half-light radius scaling as the inverse of their binding energy, and this over more than two decades. This means that earlier arriving satellites are smaller due to the tidal effects of the MW. Therefore, most halo inhabitants appear to have their structural parameters shaped by MW tides and also by ram-pressure for the most recent arrivals, the dwarf galaxies. The correlations found in this study can be used as tools to further investigate the origin of globular clusters and dwarfs, as well as the assembly history of our Galaxy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.07441v4-abstract-full').style.display = 'none'; document.getElementById('2212.07441v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 8 Figures, 2 Tables with orbital properties of globular clusters, accepted in MNRAS, December the 12, 2022, version similar to the printed version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.12601">arXiv:2207.12601</a> <span> [<a href="https://arxiv.org/pdf/2207.12601">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="High Energy Physics - Experiment">hep-ex</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1674-1137/ac9371">10.1088/1674-1137/ac9371 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Flux Variations of Cosmic Ray Air Showers Detected by LHAASO-KM2A During a Thunderstorm on 10 June 2021 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=LHAASO+Collaboration"> LHAASO Collaboration</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+L+X">L. X. Bai</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+Z">Zhe Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Zhen 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+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">Liang 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+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>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X+J">X. J. Chen</a> , et al. (248 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.12601v2-abstract-short" style="display: inline;"> The Large High Altitude Air Shower Observatory (LHAASO) has three sub-arrays, KM2A, WCDA and WFCTA. The flux variations of cosmic ray air showers were studied by analyzing the KM2A data during the thunderstorm on 10 June 2021. The number of shower events that meet the trigger conditions increases significantly in atmospheric electric fields, with maximum fractional increase of 20%. The variations… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.12601v2-abstract-full').style.display = 'inline'; document.getElementById('2207.12601v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.12601v2-abstract-full" style="display: none;"> The Large High Altitude Air Shower Observatory (LHAASO) has three sub-arrays, KM2A, WCDA and WFCTA. The flux variations of cosmic ray air showers were studied by analyzing the KM2A data during the thunderstorm on 10 June 2021. The number of shower events that meet the trigger conditions increases significantly in atmospheric electric fields, with maximum fractional increase of 20%. The variations of trigger rates (increases or decreases) are found to be strongly dependent on the primary zenith angle. The flux of secondary particles increases significantly, following a similar trend with that of the shower events. To better understand the observed behavior, Monte Carlo simulations are performed with CORSIKA and G4KM2A (a code based on GEANT4). We find that the experimental data (in saturated negative fields) are in good agreement with simulations, assuming the presence of a uniform upward electric field of 700 V/cm with a thickness of 1500 m in the atmosphere above the observation level. Due to the acceleration/deceleration and deflection by the atmospheric electric field, the number of secondary particles with energy above the detector threshold is modified, resulting in the changes in shower detection rate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.12601v2-abstract-full').style.display = 'none'; document.getElementById('2207.12601v2-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Chinese Phys. C 47 015001 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.06565">arXiv:2203.06565</a> <span> [<a href="https://arxiv.org/pdf/2203.06565">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ac5181">10.3847/2041-8213/ac5181 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth's Magnetosphere </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Qi%2C+Y">Yi Qi</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+T+C">Tak Chu Li</a>, <a href="/search/astro-ph?searchtype=author&query=Russell%2C+C+T">Christopher T. Russell</a>, <a href="/search/astro-ph?searchtype=author&query=Ergun%2C+R+E">Robert E. Ergun</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Ying-Dong Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Hubbert%2C+M">Mark Hubbert</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.06565v1-abstract-short" style="display: inline;"> Magnetic reconnection plays an important role in converting energy while modifying field topology. This process takes place in varied plasma environments in which the transport of magnetic flux is intrinsic. Identifying active magnetic reconnection sites in in-situ observations is challenging. A new technique, Magnetic Flux Transport (MFT) analysis, has been developed recently and proven in numeri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.06565v1-abstract-full').style.display = 'inline'; document.getElementById('2203.06565v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.06565v1-abstract-full" style="display: none;"> Magnetic reconnection plays an important role in converting energy while modifying field topology. This process takes place in varied plasma environments in which the transport of magnetic flux is intrinsic. Identifying active magnetic reconnection sites in in-situ observations is challenging. A new technique, Magnetic Flux Transport (MFT) analysis, has been developed recently and proven in numerical simulation for identifying active reconnection efficiently and accurately. In this study, we examine the MFT process in 37 previously reported electron diffusion region (EDR)/reconnection-line crossing events at the dayside magnetopause and in the magnetotail and turbulent magnetosheath using Magnetospheric Multiscale measurements. The coexisting inward and outward MFT flows at an X-point provides a signature that magnetic field lines become disconnected and reconnected. The application of MFT analysis to in-situ observations demonstrates that MFT can successfully identify active reconnection sites under complex varied conditions, including asymmetric and turbulent upstream conditions. It also provides a higher rate of identification than plasma outflow jets alone. MFT can be applied to in situ measurements from both single- and multi-spacecraft missions and laboratory experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.06565v1-abstract-full').style.display = 'none'; document.getElementById('2203.06565v1-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 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 1 table, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal Letters, 926, L34, 2022 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.01953">arXiv:2203.01953</a> <span> [<a href="https://arxiv.org/pdf/2203.01953">pdf</a>, <a href="https://arxiv.org/format/2203.01953">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stac644">10.1093/mnras/stac644 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An extended stellar halo discovered in the Fornax dwarf spheroidal using Gaia EDR3 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Pawlowski%2C+M">Marcel Pawlowski</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.01953v2-abstract-short" style="display: inline;"> We have studied the extent of the Red Giant Branch stellar population in the Fornax dwarf spheroidal galaxy using the spatially extended and homogeneous data set from Gaia EDR3. Our preselection of stars belonging to Fornax is based on their proper motions, parallaxes and color-magnitude diagram. The latter criteria provide a Fornax star sample, which we further restrict by color and magnitude to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.01953v2-abstract-full').style.display = 'inline'; document.getElementById('2203.01953v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.01953v2-abstract-full" style="display: none;"> We have studied the extent of the Red Giant Branch stellar population in the Fornax dwarf spheroidal galaxy using the spatially extended and homogeneous data set from Gaia EDR3. Our preselection of stars belonging to Fornax is based on their proper motions, parallaxes and color-magnitude diagram. The latter criteria provide a Fornax star sample, which we further restrict by color and magnitude to eliminate contaminations due to either Milky Way stars or QSOs. The precision of the data has been sufficient to reach extremely small contaminations (0.02 to 0.3%), allowing us to reach to a background level 12 magnitudes deeper than the central surface brightness of Fornax. We discover a break in the density profile, which reveals the presence of an additional component that extents 2.1 degree in radius, i.e. 5.4 kpc, and almost seven times the half-light radius of Fornax. The extended new component represents 10% of the stellar mass of Fornax, and behaves like an extended halo. The absence of tidally elongated features at such an unprecedented depth (equivalent to $37.94\pm0.16$ mag ${\rm arcsec}^{-2}$ in V-band) rules out a possible role of tidal stripping. We suggest instead that Fornax is likely at first infall, and has lost its gas very recently, which consequently leads to a lack of gravity implying that residual stars have spherically expanded to form the newly discovered stellar halo of Fornax. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.01953v2-abstract-full').style.display = 'none'; document.getElementById('2203.01953v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 10 figures, 4 tables, MNRAS, in press, version based on proofs</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.01295">arXiv:2112.01295</a> <span> [<a href="https://arxiv.org/pdf/2112.01295">pdf</a>, <a href="https://arxiv.org/ps/2112.01295">ps</a>, <a href="https://arxiv.org/format/2112.01295">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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 Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</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/10.1140/epjc/s10052-022-10463-1">10.1140/epjc/s10052-022-10463-1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Exact solution for accretion onto a moving charged dilaton black hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Yang%2C+R">Rong-Jia Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yinan Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+L">Lei Jiao</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="2112.01295v2-abstract-short" style="display: inline;"> We present an analytic solution for accretion of a gaseous medium with adiabatic equation of state onto a charged dilaton black hole which moves at a constant velocity. We determine the four-velocity of accreted flow and find that it possesses axial symmetry. We obtain the particle number density and the accretion rate which depend on the mass, the magnetic charge, and the dilation of black hole,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.01295v2-abstract-full').style.display = 'inline'; document.getElementById('2112.01295v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.01295v2-abstract-full" style="display: none;"> We present an analytic solution for accretion of a gaseous medium with adiabatic equation of state onto a charged dilaton black hole which moves at a constant velocity. We determine the four-velocity of accreted flow and find that it possesses axial symmetry. We obtain the particle number density and the accretion rate which depend on the mass, the magnetic charge, and the dilation of black hole, meaning that these parameters take important roles in the process of accretion. Possible theoretical and observational constraints on the parameter related to the dilation are discussed. The results may help us to get deeper understanding of the behavior of accreted flow near the event horizon of black hole. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.01295v2-abstract-full').style.display = 'none'; document.getElementById('2112.01295v2-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Eur. Phys. J. C 82, 502 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.06545">arXiv:2111.06545</a> <span> [<a href="https://arxiv.org/pdf/2111.06545">pdf</a>, <a href="https://arxiv.org/ps/2111.06545">ps</a>, <a href="https://arxiv.org/format/2111.06545">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1126/science.abg5137">10.1126/science.abg5137 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Peta-electron volt gamma-ray emission from the Crab Nebula </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=The+LHAASO+Collaboration"> The LHAASO Collaboration</a>, <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+L+X">L. X. Bai</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+H">H. Cai</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+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+B+M">B. 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+J">J. 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">Liang 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> , et al. (250 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2111.06545v1-abstract-short" style="display: inline;"> The Crab pulsar and the surrounding nebula powered by the pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind is a bright source of gamma-rays carrying crucial information about this complex conglomerate. We report the detection of $纬$-rays with a spectrum showing gradual steepening over three energy decades, from $5\times 10^{-4}$ to $1.1$ pet… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.06545v1-abstract-full').style.display = 'inline'; document.getElementById('2111.06545v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.06545v1-abstract-full" style="display: none;"> The Crab pulsar and the surrounding nebula powered by the pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind is a bright source of gamma-rays carrying crucial information about this complex conglomerate. We report the detection of $纬$-rays with a spectrum showing gradual steepening over three energy decades, from $5\times 10^{-4}$ to $1.1$ petaelectronvolt (PeV). The ultra-high-energy photons exhibit the presence of a PeV electron accelerator (a pevatron) with an acceleration rate exceeding 15% of the absolute theoretical limit. Assuming that unpulsed $纬$-rays are produced at the termination of the pulsar's wind, we constrain the pevatron's size, between $0.025$ and $0.1$ pc, and the magnetic field $\approx 110 渭$G. The production rate of PeV electrons, $2.5 \times 10^{36}$ erg $\rm s^{-1}$, constitutes 0.5% of the pulsar's spin-down luminosity, although we do not exclude a non-negligible contribution of PeV protons to the production of the highest energy $纬$-rays. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.06545v1-abstract-full').style.display = 'none'; document.getElementById('2111.06545v1-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 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">43 pages, 13 figures, 2 tables; Published in Science</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science, 2021, Vol 373, Issue 6553, pp. 425-430 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.02898">arXiv:2109.02898</a> <span> [<a href="https://arxiv.org/pdf/2109.02898">pdf</a>, <a href="https://arxiv.org/ps/2109.02898">ps</a>, <a href="https://arxiv.org/format/2109.02898">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41550-020-01294-9">10.1038/s41550-020-01294-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Potential PeVatron supernova remnant G106.3+2.7 seen in the highest-energy gamma rays </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Amenomori%2C+M">M. Amenomori</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=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D">D. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W+Y">W. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cirennima"> Cirennima</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+L+K">L. K. Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+J+H">J. H. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+K">K. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z+Y">Z. Y. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Q">Qi Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Y">Y. Y. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+Z+T">Z. T. He</a>, <a href="/search/astro-ph?searchtype=author&query=Hibino%2C+K">K. Hibino</a>, <a href="/search/astro-ph?searchtype=author&query=Hotta%2C+N">N. Hotta</a> , et al. (70 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.02898v1-abstract-short" style="display: inline;"> Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called 'PeVatrons' inside our Galaxy. Although a characteristic feature of a PeVatron is expected to be a hard gamma-ray energy spectrum that extends beyond 100 teraelectronvolts (TeV) without a cutoff, none of the currently known sources exhibits… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.02898v1-abstract-full').style.display = 'inline'; document.getElementById('2109.02898v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.02898v1-abstract-full" style="display: none;"> Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called 'PeVatrons' inside our Galaxy. Although a characteristic feature of a PeVatron is expected to be a hard gamma-ray energy spectrum that extends beyond 100 teraelectronvolts (TeV) without a cutoff, none of the currently known sources exhibits such a spectrum due to the low maximum energy of accelerated cosmic rays or insufficient detector sensitivity around 100 TeV. Here we report the observation of gamma-ray emission from the supernova remnant G106.3+2.7 above 10 TeV. This work provides flux data points up to and above 100 TeV and indicates that the very-high-energy gamma-ray emission above 10 TeV is well correlated with a molecular cloud rather than the pulsar PSR J2229+6114. Regarding the gamma-ray emission mechanism of G106.3+2.7, this morphological feature appears to favor a hadronic origin via the 蟺0 decay caused by accelerated relativistic protons over a leptonic one via the inverse-Compton scattering by relativistic electrons. Furthermore, we point out that an X-ray flux upper limit on the synchrotron spectrum would provide important information to firmly establish the hadronic scenario as the mechanism of particle acceleration at the source. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.02898v1-abstract-full').style.display = 'none'; document.getElementById('2109.02898v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published in Nature Astronomy</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Astronomy, 5, 460-464 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.01064">arXiv:2107.01064</a> <span> [<a href="https://arxiv.org/pdf/2107.01064">pdf</a>, <a href="https://arxiv.org/ps/2107.01064">ps</a>, <a href="https://arxiv.org/format/2107.01064">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.127.031102">10.1103/PhysRevLett.127.031102 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Gamma-ray Observation of the Cygnus Region in the 100 TeV Energy Region </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Amenomori%2C+M">M. Amenomori</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=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D">D. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W+Y">W. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cirennima"> Cirennima</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+L+K">L. K. Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+J+H">J. H. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+K">K. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z+Y">Z. Y. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Q">Qi Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gomi%2C+A">A. Gomi</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Y">Y. Y. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+Z+T">Z. T. He</a>, <a href="/search/astro-ph?searchtype=author&query=Hibino%2C+K">K. Hibino</a> , et al. (88 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="2107.01064v1-abstract-short" style="display: inline;"> We report observations of gamma-ray emissions with energies in the 100 TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1 with the pulsar moving away f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.01064v1-abstract-full').style.display = 'inline'; document.getElementById('2107.01064v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.01064v1-abstract-full" style="display: none;"> We report observations of gamma-ray emissions with energies in the 100 TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1 with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.01064v1-abstract-full').style.display = 'none'; document.getElementById('2107.01064v1-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 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in the Physical Review 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/2107.00014">arXiv:2107.00014</a> <span> [<a href="https://arxiv.org/pdf/2107.00014">pdf</a>, <a href="https://arxiv.org/format/2107.00014">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202141058">10.1051/0004-6361/202141058 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Which Milky Way masses are consistent with the slightly declining 5-25 kpc rotation curve? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a>, <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jianling Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin 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="2107.00014v4-abstract-short" style="display: inline;"> Discoveries of extended rotation curves have suggested the presence of dark matter in spiral galaxy haloes. It has led to many studies that estimated the galaxy total mass, mostly by using the Navarro Frenk and White (NFW) density profile. We aim at verifying how the choice of the dark-matter profile may affect the predicted values of extrapolated total masses. We have considered the recent Milky… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.00014v4-abstract-full').style.display = 'inline'; document.getElementById('2107.00014v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.00014v4-abstract-full" style="display: none;"> Discoveries of extended rotation curves have suggested the presence of dark matter in spiral galaxy haloes. It has led to many studies that estimated the galaxy total mass, mostly by using the Navarro Frenk and White (NFW) density profile. We aim at verifying how the choice of the dark-matter profile may affect the predicted values of extrapolated total masses. We have considered the recent Milky Way (MW) rotation curve, firstly because of its unprecedented accuracy, and secondly because the Galactic disk is amongst the least affected by past major mergers having fully reshaped the initial disk. We find that the use of NFW profile (or its generalized form, gNFW) for calculating the dark-matter contribution to the MW rotation curve generates apparently inconsistent results, e.g., an increase of the baryonic mass leads to increase of the dark matter mass. Furthermore we find that NFW and gNFW profile narrow the total mass range, leading to a possible methodological bias particularly against small MW masses. By using the Einasto profile that is more appropriate to represent cold dark matter haloes, we finally find that the Milky Way slightly decreasing rotation curve favors total mass that can be as small as 2.6 $\times 10^{11}$ $M_{\odot}$, disregarding any other dynamical tracers further out in the MW. It is inconsistent with values larger than 18 $\times 10^{11}$ $M_{\odot}$ for any kind of CDM dark-matter halo profiles, under the assumption that stars and gas do not influence the predicted dark matter distribution in the MW. This methodological paper encourages the use of the Einasto profile for characterizing rotation curves with the aim of evaluating their total masses. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.00014v4-abstract-full').style.display = 'none'; document.getElementById('2107.00014v4-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 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 6 Figures, 5 Tables including Table A-1 with re-evaluated error bars on the Milky Way rotation curve. After proof editing and to be published in the Astronomy & Astrophysics 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/2104.05181">arXiv:2104.05181</a> <span> [<a href="https://arxiv.org/pdf/2104.05181">pdf</a>, <a href="https://arxiv.org/ps/2104.05181">ps</a>, <a href="https://arxiv.org/format/2104.05181">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.126.141101">10.1103/PhysRevLett.126.141101 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Amenomori%2C+M">M. Amenomori</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=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D">D. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W+Y">W. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cirennima"> Cirennima</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+L+K">L. K. Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+J+H">J. H. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+K">K. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z+Y">Z. Y. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Q">Qi Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Y">Y. Y. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+Z+T">Z. T. He</a>, <a href="/search/astro-ph?searchtype=author&query=Hibino%2C+K">K. Hibino</a>, <a href="/search/astro-ph?searchtype=author&query=Hotta%2C+N">N. Hotta</a> , et al. (70 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2104.05181v2-abstract-short" style="display: inline;"> We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of $蟺^0$'s produced through the interaction of pr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05181v2-abstract-full').style.display = 'inline'; document.getElementById('2104.05181v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.05181v2-abstract-full" style="display: none;"> We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of $蟺^0$'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05181v2-abstract-full').style.display = 'none'; document.getElementById('2104.05181v2-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 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in the Physical Review Letters</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 126, 141101 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.04965">arXiv:2104.04965</a> <span> [<a href="https://arxiv.org/pdf/2104.04965">pdf</a>, <a href="https://arxiv.org/ps/2104.04965">ps</a>, <a href="https://arxiv.org/format/2104.04965">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/10.1103/PhysRevD.104.062007">10.1103/PhysRevD.104.062007 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Calibration of the Air Shower Energy Scale of the Water and Air Cherenkov Techniques in the LHAASO experiment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=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+L+X">L. X. Bai</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+H">H. Cai</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+Z+C+Z">Z. Cao Z. 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=Chang%2C+X+C">X. C. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+B+M">B. M. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">J. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. 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. (233 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2104.04965v2-abstract-short" style="display: inline;"> The Wide Field-of-View Cherenkov Telescope Array (WFCTA) and the Water Cherenkov Detector Arrays (WCDA) of LHAASO are designed to work in combination for measuring the energy spectra of various cosmic ray species over a very wide energy range from a few TeV to 10 PeV. The energy calibration of WCDA can be achieved with a proven technique of measuring the westward shift of the Moon shadow of galact… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.04965v2-abstract-full').style.display = 'inline'; document.getElementById('2104.04965v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.04965v2-abstract-full" style="display: none;"> The Wide Field-of-View Cherenkov Telescope Array (WFCTA) and the Water Cherenkov Detector Arrays (WCDA) of LHAASO are designed to work in combination for measuring the energy spectra of various cosmic ray species over a very wide energy range from a few TeV to 10 PeV. The energy calibration of WCDA can be achieved with a proven technique of measuring the westward shift of the Moon shadow of galactic cosmic rays due to the geomagnetic field. This deflection angle $螖$ is inversely proportional to the energy of the cosmic rays. The precise measurements of the shifts by WCDA allows us to calibrate its energy scale for energies as high as 35 TeV. The energy scale measured by WCDA can be used to cross calibrate the energy reconstructed by WFCTA, which spans the whole energy range up to 10 PeV. In this work, we will demonstrate the feasibility of the method using the data collected from April 2019 to January 2020 by the WFCTA array and WCDA-1 detector, the first of the three water Cherenkov ponds, already commissioned at LHAASO site. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.04965v2-abstract-full').style.display = 'none'; document.getElementById('2104.04965v2-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 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. D 104, 062007 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.14622">arXiv:2012.14622</a> <span> [<a href="https://arxiv.org/pdf/2012.14622">pdf</a>, <a href="https://arxiv.org/format/2012.14622">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 Detectors">physics.ins-det</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 - Experiment">hep-ex</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1140/epjc/s10052-021-09414-z">10.1140/epjc/s10052-021-09414-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Construction and On-site Performance of the LHAASO WFCTA Camera </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=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+L+X">L. X. Bai</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+H">H. Cai</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+Z">Z. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Z. 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=Chang%2C+X+C">X. C. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+B+M">B. M. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">J. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. 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> , et al. (234 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="2012.14622v2-abstract-short" style="display: inline;"> The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.14622v2-abstract-full').style.display = 'inline'; document.getElementById('2012.14622v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.14622v2-abstract-full" style="display: none;"> The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.14622v2-abstract-full').style.display = 'none'; document.getElementById('2012.14622v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">45 pages, 21 figures, article</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Eur. Phys. J. C 81, 657 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.00005">arXiv:2012.00005</a> <span> [<a href="https://arxiv.org/pdf/2012.00005">pdf</a>, <a href="https://arxiv.org/format/2012.00005">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> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/abdf4a">10.3847/1538-4357/abdf4a <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Encounter of Parker Solar Probe and a Comet-like Object During Their Perihelia: Model Predictions and Measurements </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=He%2C+J">Jiansen He</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+B">Bo Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+L">Liping Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Hou%2C+C">Chuanpeng Hou</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+L">Lei Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Ip%2C+W">Wing-Huen Ip</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y">Yingdong Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+C">Chuanfei Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Duan%2C+D">Die Duan</a>, <a href="/search/astro-ph?searchtype=author&query=Zong%2C+Q">Qiugang Zong</a>, <a href="/search/astro-ph?searchtype=author&query=Bale%2C+S+D">Stuart D. Bale</a>, <a href="/search/astro-ph?searchtype=author&query=Pulupa%2C+M">Marc Pulupa</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnell%2C+J+W">John W. Bonnell</a>, <a href="/search/astro-ph?searchtype=author&query=de+Wit%2C+T+D">Thierry Dudok de Wit</a>, <a href="/search/astro-ph?searchtype=author&query=Goetz%2C+K">Keith Goetz</a>, <a href="/search/astro-ph?searchtype=author&query=Harvey%2C+P+R">Peter R. Harvey</a>, <a href="/search/astro-ph?searchtype=author&query=MacDowall%2C+R+J">Robert J. MacDowall</a>, <a href="/search/astro-ph?searchtype=author&query=Malaspina%2C+D+M">David M. Malaspina</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.00005v1-abstract-short" style="display: inline;"> Parker Solar Probe (PSP) aims at exploring the nascent solar wind close to the Sun. Meanwhile, PSP is also expected to encounter small objects like comets and asteroids. In this work, we survey the ephemerides to find a chance of recent encounter, and then model the interaction between released dusty plasmas and solar wind plasmas. On 2019 September 2, a comet-like object 322P/SOHO just passed its… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.00005v1-abstract-full').style.display = 'inline'; document.getElementById('2012.00005v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.00005v1-abstract-full" style="display: none;"> Parker Solar Probe (PSP) aims at exploring the nascent solar wind close to the Sun. Meanwhile, PSP is also expected to encounter small objects like comets and asteroids. In this work, we survey the ephemerides to find a chance of recent encounter, and then model the interaction between released dusty plasmas and solar wind plasmas. On 2019 September 2, a comet-like object 322P/SOHO just passed its perihelion flying to a heliocentric distance of 0.12 au, and swept by PSP at a relative distance as close as 0.025 au. We present the dynamics of dust particles released from 322P, forming a curved dust tail. Along the PSP path in the simulated inner heliosphere, the states of plasma and magnetic field are sampled and illustrated, with the magnetic field sequences from simulation results being compared directly with the in-situ measurements from PSP. Through comparison, we suggest that 322P might be at a deficient activity level releasing limited dusty plasmas during its way to becoming a "rock comet". We also present images of solar wind streamers as recorded by WISPR, showing an indication of dust bombardment for the images superposed with messy trails. We observe from LASCO coronagraph that 322P was transiting from a dimming region to a relatively bright streamer during its perihelion passage, and simulate to confirm that 322P was flying from relatively faster to slower solar wind streams, modifying local plasma states of the streams. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.00005v1-abstract-full').style.display = 'none'; document.getElementById('2012.00005v1-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 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.06205">arXiv:2010.06205</a> <span> [<a href="https://arxiv.org/pdf/2010.06205">pdf</a>, <a href="https://arxiv.org/ps/2010.06205">ps</a>, <a href="https://arxiv.org/format/2010.06205">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 class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1674-1137/abd01b">10.1088/1674-1137/abd01b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The observation of the Crab Nebula with LHAASO-KM2A for the performance study </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aharonian%2C+F">F. Aharonian</a>, <a href="/search/astro-ph?searchtype=author&query=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+L+X">L. X. Bai</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+H">H. Cai</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+Z">Z. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Cao%2C+Z">Z. 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=Chang%2C+X+C">X. C. Chang</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+B+M">B. M. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+J">J. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+L">L. 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> , et al. (234 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2010.06205v1-abstract-short" style="display: inline;"> As a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to cover a large fraction of the northern sky to hunt for gamma-ray sources at energies above 10 TeV. Even though the detector construction is still underway, a half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the pipeline of KM2A data analysis and the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.06205v1-abstract-full').style.display = 'inline'; document.getElementById('2010.06205v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.06205v1-abstract-full" style="display: none;"> As a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to cover a large fraction of the northern sky to hunt for gamma-ray sources at energies above 10 TeV. Even though the detector construction is still underway, a half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the pipeline of KM2A data analysis and the first observation on the Crab Nebula, a standard candle in very high energy gamma-ray astronomy. We detect gamma-ray signals from the Crab Nebula in both energy ranges of 10$-$100 TeV and $>$100 TeV with high significance, by analyzing the KM2A data of 136 live days between December 2019 and May 2020. With the observations, we test the detector performance including angular resolution, pointing accuracy and cosmic ray background rejection power. The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE =(1.13$\pm$0.05$_{stat}$$\pm$0.08$_{sys}$)$\times$10$^{-14}$$\cdot$(E/20TeV)$^{-3.09\pm0.06_{stat}\pm0.02_{sys}}$ cm$^{-2}$ s$^{-1}$ TeV$^{-1}$. It is consistent with previous measurements by other experiments. This opens a new window of gamma-ray astronomy above 0.1 PeV through which ultrahigh-energy gamma-ray new phenomena, such as cosmic PeVatrons, might be discovered. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.06205v1-abstract-full').style.display = 'none'; document.getElementById('2010.06205v1-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 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 15 figures,submitted to CPC</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Chinese Phys. C 45 025002 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.11935">arXiv:2009.11935</a> <span> [<a href="https://arxiv.org/pdf/2009.11935">pdf</a>, <a href="https://arxiv.org/format/2009.11935">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="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</span> </div> </div> <p class="title is-5 mathjax"> Most dwarf spheroidal galaxies surrounding the Milky Way cannot be dark-matter dominated satellites </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hammer%2C+F">Francois Hammer</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+Y">Yanbin Yang</a>, <a href="/search/astro-ph?searchtype=author&query=Arenou%2C+F">Frederic Arenou</a>, <a href="/search/astro-ph?searchtype=author&query=Li%2C+H">Hefan Li</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+J">Jianling Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Bonifacio%2C+P">Piercarlo Bonifacio</a>, <a href="/search/astro-ph?searchtype=author&query=Babusiaux%2C+C">Carine Babusiaux</a>, <a href="/search/astro-ph?searchtype=author&query=Jiao%2C+Y">Yongjun Jiao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2009.11935v3-abstract-short" style="display: inline;"> Milky Way dwarf spheroidal galaxies are the tiniest observed galaxies and are currently associated with the largest fractions of dark matter, which is revealed by their too large velocity dispersions. However, most of them are found near their orbital pericenters. This leads to a very low probability, P = 2 $10^{-7}$, that they could be long-lived satellites such as sub-halos predicted by cosmolog… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.11935v3-abstract-full').style.display = 'inline'; document.getElementById('2009.11935v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.11935v3-abstract-full" style="display: none;"> Milky Way dwarf spheroidal galaxies are the tiniest observed galaxies and are currently associated with the largest fractions of dark matter, which is revealed by their too large velocity dispersions. However, most of them are found near their orbital pericenters. This leads to a very low probability, P = 2 $10^{-7}$, that they could be long-lived satellites such as sub-halos predicted by cosmological simulations. Their proximity to their pericenters suggests instead that they are affected by tidal shocks, which provide sufficient kinematic energy to explain their high velocity dispersions. Dependency of the dark matter properties to their distance to the Milky Way appears to favor tidally shocked and out of equilibrium dSphs instead of self-equilibrium systems dominated by dark matter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.11935v3-abstract-full').style.display = 'none'; document.getElementById('2009.11935v3-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 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 2 Figures, Printed at Proceedings of the 3rd World Summit on Exploring the Dark Side of the Universe (EDSU2020): March 9-13, 2020, Guadeloupe Islands, Eds. A. Novikov, P. Petroff and C. Royon, University of Kansas Libraries P229. An explanatory video based on hydrodynamical, N-body simulations optimizing the dynamics of stars can be found at: https://www.youtube.com/watch?v=m55iBXISYyE</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> University of Kansas Libraries, 2020-12-23, Proceedings of the 3rd World Summit on Exploring the Dark Side of the Universe (EDSU2020): March 9-13, 2020, Guadeloupe Islands, P.229 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1906.05521">arXiv:1906.05521</a> <span> [<a href="https://arxiv.org/pdf/1906.05521">pdf</a>, <a href="https://arxiv.org/ps/1906.05521">ps</a>, <a href="https://arxiv.org/format/1906.05521">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.123.051101">10.1103/PhysRevLett.123.051101 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First Detection of Photons with Energy Beyond 100 TeV from an Astrophysical Source </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Amenomori%2C+M">M. Amenomori</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=Bi%2C+X+J">X. J. Bi</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+D">D. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+T+L">T. L. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+W+Y">W. Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+X">Xu Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y">Y. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Cirennima"> Cirennima</a>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</a>, <a href="/search/astro-ph?searchtype=author&query=Ding%2C+L+K">L. K. Ding</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+J+H">J. H. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+K">K. Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z+Y">Z. Y. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+Q">Qi Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+Z+T">Z. T. He</a>, <a href="/search/astro-ph?searchtype=author&query=Hibino%2C+K">K. Hibino</a>, <a href="/search/astro-ph?searchtype=author&query=Hotta%2C+N">N. Hotta</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+H">Haibing Hu</a> , et al. (66 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="1906.05521v1-abstract-short" style="display: inline;"> We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies $E>100$ TeV. As a result, we observed 24 photon-like events with $E>100$ TeV against 5.5 b… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.05521v1-abstract-full').style.display = 'inline'; document.getElementById('1906.05521v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.05521v1-abstract-full" style="display: none;"> We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies $E>100$ TeV. As a result, we observed 24 photon-like events with $E>100$ TeV against 5.5 background events, which corresponds to 5.6$蟽$ statistical significance. This is the first detection of photons with $E>100$ TeV from an astrophysical source. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.05521v1-abstract-full').style.display = 'none'; document.getElementById('1906.05521v1-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 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">April 4, 2019; Submitted to the Physical Review Letters</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 123, 051101 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1902.02924">arXiv:1902.02924</a> <span> [<a href="https://arxiv.org/pdf/1902.02924">pdf</a>, <a href="https://arxiv.org/ps/1902.02924">ps</a>, <a href="https://arxiv.org/format/1902.02924">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/aaf80f">10.3847/1538-4357/aaf80f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Hint of Three-section Halo as Seen from the APOGEE DR14 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Chen%2C+Y+Q">Y. Q. Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+G">G. Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Xue%2C+X+X">X. X. Xue</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+J+K">J. K. Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Liang%2C+X+L">X. L. Liang</a>, <a href="/search/astro-ph?searchtype=author&query=Jia%2C+Y+P">Y. P. Jia</a>, <a href="/search/astro-ph?searchtype=author&query=Yang%2C+C+Q">C. Q. 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="1902.02924v1-abstract-short" style="display: inline;"> Based on the [Fe/H] versus [Mg/Fe] diagram and distances from APOGEE data release 14, we compare the spatial distributions, the l-Vlos diagram and the abundance gradients between high-[Mg/Fe] and low-[Mg/Fe] sequences. The two sequences are clearly shown at 5<|Z|<10 kpc in the metallicity range of -1.6 <[Fe/H] <-0.7, where the halo at |Z| > 10 kpc consists of low-[Mg/Fe] stars only. In the interme… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.02924v1-abstract-full').style.display = 'inline'; document.getElementById('1902.02924v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.02924v1-abstract-full" style="display: none;"> Based on the [Fe/H] versus [Mg/Fe] diagram and distances from APOGEE data release 14, we compare the spatial distributions, the l-Vlos diagram and the abundance gradients between high-[Mg/Fe] and low-[Mg/Fe] sequences. The two sequences are clearly shown at 5<|Z|<10 kpc in the metallicity range of -1.6 <[Fe/H] <-0.7, where the halo at |Z| > 10 kpc consists of low-[Mg/Fe] stars only. In the intermediate-metallicity range of -1.1 <[Fe/H]<-0.7, a [Mg/Fe] gradient is detected for stars at |Z|=10-30 kpc and it flattens out at |Z|>30 kpc. The l-Vlos diagram is adopted to separate halo stars from the disk by defining the transition metallicity, which is of [Fe/H]~ -1.1 dex for the high-[Mg/Fe] sequence and of [Fe/H]~-0.7 dex for the low-[Mg/Fe] sequence. The R and |Z| distributions for the high-[Mg/Fe] sequence, the thick disk at -1.1<[Fe/H]<-0.7 and the in situ halo at -1.6<[Fe/H]<-1.1, have a cutoff at R~15 kpc and |Z|~10 kpc, beyond which low-[Mg/Fe] halo stars are the main contributions. In the metallicity range of -1.6<[Fe/H]<-0.7, there is a negative metallicity gradient for the high-[Mg/Fe] halo at |Z|<8-10 kpc, while only a marginal or no slope in the [Fe/H] versus |Z| diagram for the low-[Mg/Fe] halo at |Z|<8-10 kpc, beyond which both the high-[Mg/Fe] halo and low-[Mg/Fe] halo flatten out toward |Z| > 20 kpc. These results indicate a complicated formation history of the Galaxy and we may see a hint of a three-section halo, i.e. the inner in situ halo within $|Z|~8-10$ kpc, the intermediately outer dual-mode halo at |Z|~10-30 kpc, and the extremely outer accreted halo with |Z|>30 kpc. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.02924v1-abstract-full').style.display = 'none'; document.getElementById('1902.02924v1-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 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 9 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 2019, ApJ, 871, 216 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1901.04201">arXiv:1901.04201</a> <span> [<a href="https://arxiv.org/pdf/1901.04201">pdf</a>, <a href="https://arxiv.org/ps/1901.04201">ps</a>, <a href="https://arxiv.org/format/1901.04201">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/aafe06">10.3847/1538-4357/aafe06 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Search for gamma-ray emission from the Sun during solar minimum with the ARGO-YBJ experiment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bartoli%2C+B">B. Bartoli</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=Cao%2C+Z">Z. Cao</a>, <a href="/search/astro-ph?searchtype=author&query=Catalanotti%2C+S">S. Catalanotti</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>, <a href="/search/astro-ph?searchtype=author&query=Cui%2C+S+W">S. W. Cui</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+B+Z">B. Z. Dai</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Amone%2C+A">A. D'Amone</a>, <a href="/search/astro-ph?searchtype=author&query=Danzengluobu"> Danzengluobu</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=Piazzoli%2C+B+D">B. D'Ettorre Piazzoli</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Girolamo%2C+T">T. Di Girolamo</a>, <a href="/search/astro-ph?searchtype=author&query=Di+Sciascio%2C+G">G. Di Sciascio</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+C+F">C. F. Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhaoyang Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Feng%2C+Z">Zhenyong Feng</a>, <a href="/search/astro-ph?searchtype=author&query=Gao%2C+W">W. Gao</a>, <a href="/search/astro-ph?searchtype=author&query=Gou%2C+Q+B">Q. B. Gou</a>, <a href="/search/astro-ph?searchtype=author&query=Guo%2C+Y+Q">Y. Q. Guo</a>, <a href="/search/astro-ph?searchtype=author&query=He%2C+H+H">H. H. He</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+H">Haibing Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Hu%2C+H">Hongbo Hu</a>, <a href="/search/astro-ph?searchtype=author&query=Iacovacci%2C+M">M. Iacovacci</a> , et al. (48 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="1901.04201v1-abstract-short" style="display: inline;"> The hadronic interaction of cosmic rays with solar atmosphere can produce high energy gamma rays. The gamma-ray luminosity is correlated both with the flux of primary cosmic rays and the intensity of the solar magnetic field. The gamma rays below 200 GeV have been observed by $Fermi$ without any evident energy cutoff. The bright gamma-ray flux above 100 GeV has been detected only during solar mini… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.04201v1-abstract-full').style.display = 'inline'; document.getElementById('1901.04201v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1901.04201v1-abstract-full" style="display: none;"> The hadronic interaction of cosmic rays with solar atmosphere can produce high energy gamma rays. The gamma-ray luminosity is correlated both with the flux of primary cosmic rays and the intensity of the solar magnetic field. The gamma rays below 200 GeV have been observed by $Fermi$ without any evident energy cutoff. The bright gamma-ray flux above 100 GeV has been detected only during solar minimum. The only available data in TeV range come from the HAWC observations, however outside the solar minimum. The ARGO-YBJ dataset has been used to search for sub-TeV/TeV gamma rays from the Sun during the solar minimum from 2008 to 2010, the same time period covered by the Fermi data. A suitable model containing the Sun shadow, solar disk emission and inverse-Compton emission has been developed, and the chi-square minimization method was used to quantitatively estimate the disk gamma-ray signal. The result shows that no significant gamma-ray signal is detected and upper limits to the gamma-ray flux at 0.3$-$7 TeV are set at 95\% confidence level. In the low energy range these limits are consistent with the extrapolation of the Fermi-LAT measurements taken during solar minimum and are compatible with a softening of the gamma-ray spectrum below 1 TeV. They provide also an experimental upper bound to any solar disk emission at TeV energies. Models of dark matter annihilation via long-lived mediators predicting gamma-ray fluxes > $10^{-7}$ GeV $cm^{-2}$ $s^{-1}$ below 1 TeV are ruled out by the ARGO-YBJ limits. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.04201v1-abstract-full').style.display = 'none'; document.getElementById('1901.04201v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2019. </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Jiao%2C+Y&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a 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