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class='morefewer'>Showing up to 2000 entries per page: <a href=/list/astro-ph.IM/new?skip=0&show=1000 rel="nofollow"> fewer</a> | <span style="color: #454545">more</span> | <span style="color: #454545">all</span> </div> <dl id='articles'> <h3>New submissions (showing 3 of 3 entries)</h3> <dt> <a name='item1'>[1]</a> <a href ="/abs/2503.22203" title="Abstract" id="2503.22203"> arXiv:2503.22203 </a> [<a href="/pdf/2503.22203" title="Download PDF" id="pdf-2503.22203" aria-labelledby="pdf-2503.22203">pdf</a>, <a href="https://arxiv.org/html/2503.22203v1" title="View HTML" id="html-2503.22203" aria-labelledby="html-2503.22203" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22203" title="Other formats" id="oth-2503.22203" aria-labelledby="oth-2503.22203">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> The Simons Observatory: Large Diameter and Large Load-Capacity Superconducting Magnetic Bearing for a Millimeter-Wave Polarization Modulator </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Sasaki,+D">Daichi Sasaki</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Sugiyama,+J">Junna Sugiyama</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Yamada,+K">Kyohei Yamada</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Bixler,+B">Bryce Bixler</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Sakurai,+Y">Yuki Sakurai</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Arnold,+K">Kam Arnold</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Johnson,+B+R">Bradley R. Johnson</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kusaka,+A">Akito Kusaka</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 12 pages, 14 figures. Submitted to Rev. Sci. Instrum </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Instrumentation and Methods for Astrophysics (astro-ph.IM)</span> </div> <p class='mathjax'> We present the design methodology and characterization of a superconducting magnetic bearing (SMB) system for the polarization modulator in the SAT-LF, one of the small aperture telescopes (SATs) in the Simons Observatory (SO) that is sensitive at 30/40 GHz frequency bands. SO is a ground-based cosmic microwave background (CMB) polarization experiment, with the SATs specifically aiming to search for primordial parity-odd polarization anisotropies at degree scales. Each SAT is equipped with a cryogenic, continuously rotating half-wave plate (HWP) as a polarization modulator to mitigate atmospheric $1/f$ noise and instrumental systematics. The HWP system employs an SMB, consisting of a ring-shaped magnet and superconductor, to achieve a 550 mm clear aperture and stable 2 Hz rotation at a temperature of around 50 K. One challenge for the HWP system in the SAT-LF is the large 35 kg load on the SMB due to the thicker HWP than in previous telescopes. Since the SMB stiffness is critical for maintaining the alignment of the HWP in the telescope, we developed a method to quantitatively predict the stiffness using finite element simulations with the so-called H-formulation. We evaluated the stiffness for various geometries of the magnet and superconductor, thereby optimizing their dimensions. The prediction is in excellent agreement with experimental measurements of the fabricated SMB, demonstrating a $\sim$5\% accuracy. We also demonstrated that the SMB achieves sufficiently low friction-induced heat dissipation, measured at 0.26 W when rotating at 2 Hz. The design methodology and the implementation of the SMB demonstrated here not only provides an enabling technology for the SO SAT-LF, but also is a crucial stepping stone for future CMB experiments that make use of HWP polarization modulators. </p> </div> </dd> <dt> <a name='item2'>[2]</a> <a href ="/abs/2503.22446" title="Abstract" id="2503.22446"> arXiv:2503.22446 </a> [<a href="/pdf/2503.22446" title="Download PDF" id="pdf-2503.22446" aria-labelledby="pdf-2503.22446">pdf</a>, <a href="https://arxiv.org/html/2503.22446v1" title="View HTML" id="html-2503.22446" aria-labelledby="html-2503.22446" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22446" title="Other formats" id="oth-2503.22446" aria-labelledby="oth-2503.22446">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> Stellar intensity interferometry in the photon-counting regime </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Guerin,+W">William Guerin</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hugbart,+M">Mathilde Hugbart</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Tolila,+S">Sarah Tolila</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Matthews,+N">Nolan Matthews</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Lai,+O">Olivier Lai</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Rivet,+J">Jean-Pierre Rivet</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Labeyrie,+G">G. Labeyrie</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kaiser,+R">Robin Kaiser</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> Submitted to a special issue of "Comptes Rendus. Physique" </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Instrumentation and Methods for Astrophysics (astro-ph.IM)</span> </div> <p class='mathjax'> Stellar intensity interferometry consists in measuring the correlation of the light intensity fluctuations at two telescopes observing the same star. The amplitude of the correlation is directly related to the luminosity distribution of the star, which would be unresolved by a single telescope. This technique is based on the well-known Hanbury Brown and Twiss effect. After its discovery in the 1950s, it was used in astronomy until the 1970s, and then replaced by direct (``amplitude'') interferometry, which is much more sensitive, but also much more demanding. However, in recent years, intensity interferometry has undergone a revival. In this article, we present a summary of the state-of-the-art, and we discuss in detail the signal-to-noise ratio of intensity interferometry in the framework of photon-counting detection. </p> </div> </dd> <dt> <a name='item3'>[3]</a> <a href ="/abs/2503.22657" title="Abstract" id="2503.22657"> arXiv:2503.22657 </a> [<a href="/pdf/2503.22657" title="Download PDF" id="pdf-2503.22657" aria-labelledby="pdf-2503.22657">pdf</a>, <a href="https://arxiv.org/html/2503.22657v1" title="View HTML" id="html-2503.22657" aria-labelledby="html-2503.22657" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22657" title="Other formats" id="oth-2503.22657" aria-labelledby="oth-2503.22657">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> dolphin: A fully automated forward modeling pipeline powered by artificial intelligence for galaxy-scale strong lenses </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Shajib,+A+J">Anowar J. Shajib</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Nihal,+N+S">Nafis Sadik Nihal</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Tan,+C+Y">Chin Yi Tan</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Sahu,+V">Vedant Sahu</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Birrer,+S">Simon Birrer</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Treu,+T">Tommaso Treu</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Frieman,+J">Joshua Frieman</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 11 pages, 5 figures, 1 table. GitHub link of the software: <a href="https://github.com/ajshajib/dolphin" rel="external noopener nofollow" class="link-external link-https">this https URL</a> </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Instrumentation and Methods for Astrophysics (astro-ph.IM)</span>; Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA) </div> <p class='mathjax'> Strong gravitational lensing is a powerful tool for probing the internal structure and evolution of galaxies, the nature of dark matter, and the expansion history of the Universe, among many other scientific applications. For almost all of these science cases, modeling the lensing mass distribution is essential. For that, forward modeling of imaging data to the pixel level is the standard method used for galaxy-scale lenses. However, the traditional workflow of forward lens modeling necessitates a significant amount of human investigator time, requiring iterative tweaking and tuning of the model settings through trial and error. An automated lens modeling pipeline can substantially reduce the need for human investigator time. In this paper, we present \textsc{dolphin}, an automated lens modeling pipeline that combines artificial intelligence with the traditional forward modeling framework to enable full automation of the modeling workflow. \textsc{dolphin} uses a neural network model to perform visual recognition of the strong lens components, then autonomously sets up a lens model with appropriate complexity, and fits the model with the modeling engine, lenstronomy. Thanks to the versatility of lenstronomy, dolphin can autonomously model both galaxy-galaxy and galaxy-quasar strong lenses. </p> </div> </dd> </dl> <dl id='articles'> <h3>Cross submissions (showing 5 of 5 entries)</h3> <dt> <a name='item4'>[4]</a> <a href ="/abs/2503.21871" title="Abstract" id="2503.21871"> arXiv:2503.21871 </a> (cross-list from astro-ph.HE) [<a href="/pdf/2503.21871" title="Download PDF" id="pdf-2503.21871" aria-labelledby="pdf-2503.21871">pdf</a>, <a href="https://arxiv.org/html/2503.21871v1" title="View HTML" id="html-2503.21871" aria-labelledby="html-2503.21871" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.21871" title="Other formats" id="oth-2503.21871" aria-labelledby="oth-2503.21871">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> Accelerating LISA inference with Gaussian processes </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Gammal,+J+E">Jonas El Gammal</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Buscicchio,+R">Riccardo Buscicchio</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Nardini,+G">Germano Nardini</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Torrado,+J">Jes煤s Torrado</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 21 pages, 12 figures </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">High Energy Astrophysical Phenomena (astro-ph.HE)</span>; Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc) </div> <p class='mathjax'> Source inference for deterministic gravitational waves is a computationally demanding task in LISA. In a novel approach, we investigate the capability of Gaussian Processes to learn the posterior surface in order to reconstruct individual signal posteriors. We use GPry, which automates this reconstruction through active learning, using a very small number of likelihood evaluations, without the need for pretraining. We benchmark GPry against the cutting-edge nested sampler nessai, by injecting individually three signals on LISA noisy data simulated with Balrog: a white dwarf binary (DWD), a stellar-mass black hole binary (stBHB), and a super-massive black hole binary (SMBHB). We find that GPry needs $\mathcal O(10^{-2})$ fewer likelihood evaluations to achieve an inference accuracy comparable to nessai, with Jensen-Shannon divergence $D_{\scriptscriptstyle \mathrm{JS}} \lesssim 0.01$ for the DWD, and $D_{\scriptscriptstyle \mathrm{JS}} \lesssim 0.05$ for the SMBHB. Lower accuracy is found for the less Gaussian posterior of the stBHB: $D_{\scriptscriptstyle \mathrm{JS}} \lesssim 0.2$. Despite the overhead costs of GPry, we obtain a speed-up of $\mathcal O(10^2)$ for the slowest cases of stBHB and SMBHB. In conclusion, active-learning Gaussian process frameworks show great potential for rapid LISA parameter inference, especially for costly likelihoods, enabling suppression of computational costs without the trade-off of approximations in the calculations. </p> </div> </dd> <dt> <a name='item5'>[5]</a> <a href ="/abs/2503.22031" title="Abstract" id="2503.22031"> arXiv:2503.22031 </a> (cross-list from astro-ph.EP) [<a href="/pdf/2503.22031" title="Download PDF" id="pdf-2503.22031" aria-labelledby="pdf-2503.22031">pdf</a>, <a href="https://arxiv.org/html/2503.22031v1" title="View HTML" id="html-2503.22031" aria-labelledby="html-2503.22031" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22031" title="Other formats" id="oth-2503.22031" aria-labelledby="oth-2503.22031">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> Measurement of Methane Line Broadening in Hot Hydrogen/Helium Atmospheres at $位$ = 1.60-1.63 渭m for Substellar Object Spectroscopy </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hosokawa,+K">Ko Hosokawa</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kotani,+T">Takayuki Kotani</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kawahara,+H">Hajime Kawahara</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kawashima,+Y">Yui Kawashima</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Masuda,+K">Kento Masuda</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Takahashi,+A">Aoi Takahashi</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Yoshioka,+K">Kazuo Yoshioka</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 22 pages, 14 figures, accepted for publication in ApJ </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Earth and Planetary Astrophysics (astro-ph.EP)</span>; Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR) </div> <p class='mathjax'> Recent high-dispersion spectroscopy from ground-based telescopes and high-precision spectroscopy from space observatories have enabled atmospheric observations of substellar objects, such as brown dwarfs and hot gaseous exoplanets, with sufficient precision to make ambient gas differences in molecular line broadening a significant factor. In this paper, we experimentally measured the pressure broadening of methane in a high-temperature hydrogen-helium background atmosphere in the H band, which had not been previously measured. The experiment used glass cells, inserted in a tube furnace, filled with methane in a hydrogen-helium background atmosphere or pure methane gas. Spectra were obtained at four temperatures ranging from room temperature to 1000 K, in the wavelength range 1.60-1.63 $\mu$m, using a tunable laser, yielding eight high-resolution spectra in total. A full Bayesian analysis was performed on the obtained spectra, using the differentiable spectral model ExoJAX and the Hamiltonian Monte Carlo for inferring a large number of parameters, allowing us to infer the H2/He pressure broadening for 22 transitions mainly in the R-branch of the 2$\nu_3$ band. As a result, we found a temperature exponent of approximately 0.27 and a reference width at 296 K of around 0.040 for $ J_{lower} $ = 13-20. This temperature dependency is much milder than that provided by the molecular database ExoMol, yielding a line width approximately 5-45% smaller than ExoMol at 296 K, but similar at 1000 K. Our results suggest the need for further accumulation of experimental data for spectral analysis of substellar objects with hydrogen-helium atmospheres. </p> </div> </dd> <dt> <a name='item6'>[6]</a> <a href ="/abs/2503.22361" title="Abstract" id="2503.22361"> arXiv:2503.22361 </a> (cross-list from astro-ph.HE) [<a href="/pdf/2503.22361" title="Download PDF" id="pdf-2503.22361" aria-labelledby="pdf-2503.22361">pdf</a>, <a href="https://arxiv.org/html/2503.22361v1" title="View HTML" id="html-2503.22361" aria-labelledby="html-2503.22361" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22361" title="Other formats" id="oth-2503.22361" aria-labelledby="oth-2503.22361">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> A novel approach of optimizing the image cleaning performance of Imaging Atmospheric Cherenkov Telescopes: Application to a time-based cleaning for H.E.S.S </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=%C4%86eli%C4%87,+J">Jelena 膯eli膰</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Lang,+R+G">Rodrigo Guedes Lang</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Steinmassl,+S">Simon Steinmassl</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hinton,+J">Jim Hinton</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Funk,+S">Stefan Funk</a></div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">High Energy Astrophysical Phenomena (astro-ph.HE)</span>; Instrumentation and Methods for Astrophysics (astro-ph.IM) </div> <p class='mathjax'> This study introduces a time-based cleaning method for H.E.S.S. using CT5 in monoscopic mode and presents an optimization workflow for image-cleaning algorithms to enhance telescope sensitivity while minimizing systematic biases. We evaluate three methods - tail-cut cleaning and two flavours of time-based cleaning TIME3D and TIME4D - and find best-cut configurations for two cases: optimal overall sensitivity and minimal energy threshold. TIME3D achieves a $\sim 15\%$ improvement with regard to the standard tail-cut cleaning for $E < 300$ GeV, with a $\sim 200\%$ improvement for the first energy bin (36.5 GeV < E < 64.9 GeV), providing a more stable performance across a wider energy range by preserving more signal. TIME4D achieves a $\sim 20\%$ improvement at low energies due to superior NSB noise suppression, allowing for an enhanced capability of detecting sources at the lowest energies. We demonstrate that using first-order estimations of the performance of a cleaning, such as image size retaining or NSB pixel reduction, cannot provide a full picture of the expected result in the final sensitivity. Beyond expanding the effective area at low energies, sensitivity improvement requires precise event reconstruction, including improved energy and directional accuracy. Enhanced gamma-hadron separation and optimized pre-selection cuts further boost sensitivity. The proposed pipeline fully explores this, providing a fair and robust comparison between different cleaning methods. The method is general and can be applied to other IACT systems like VERITAS, MAGIC. By advancing data-driven image cleaning, this work lays the groundwork for detecting faint astrophysical sources and deepening our understanding of high-energy cosmic phenomena. </p> </div> </dd> <dt> <a name='item7'>[7]</a> <a href ="/abs/2503.22497" title="Abstract" id="2503.22497"> arXiv:2503.22497 </a> (cross-list from astro-ph.SR) [<a href="/pdf/2503.22497" title="Download PDF" id="pdf-2503.22497" aria-labelledby="pdf-2503.22497">pdf</a>, <a href="https://arxiv.org/html/2503.22497v1" title="View HTML" id="html-2503.22497" aria-labelledby="html-2503.22497" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22497" title="Other formats" id="oth-2503.22497" aria-labelledby="oth-2503.22497">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> Euclid Quick Data Release (Q1): A photometric search for ultracool dwarfs in the Euclid Deep Fields </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=%C5%BDerjal,+M">M. 沤erjal</a> (1 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dominguez-Tagle,+C">C. Dominguez-Tagle</a> (1 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Sedighi,+N">N. Sedighi</a> (1 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Mart%C3%ADn,+E+L">E. L. Mart铆n</a> (3 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Lodieu,+N">N. Lodieu</a> (4 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Goldman,+B">B. Goldman</a> (5 and 6), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Reyl%C3%A9,+C">C. Reyl茅</a> (7), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Smart,+R+L">R. L. Smart</a> (8 and 9), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Mohandasan,+A">A. Mohandasan</a> (7), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Osorio,+M+R+Z">M. R. Zapatero Osorio</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Barrado,+D">D. Barrado</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Buitrago,+P+M">P. Mas Buitrago</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Vitas,+N">N. Vitas</a> (1), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cruz,+P">P. Cruz</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=B%C3%A9jar,+V+J+S">V. J. S. B茅jar</a> (3 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Bouy,+H">H. Bouy</a> (11 and 12), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Burgasser,+A">A. Burgasser</a> (13), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Torres,+S+M">S. Mu帽oz Torres</a> (4), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Phan-Bao,+N">N. Phan-Bao</a> (14 and 15), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Solano,+E">E. Solano</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Tata,+R">R. Tata</a> (16), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Tsilia,+S">S. Tsilia</a> (3 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Zhang,+J">J.-Y. Zhang</a> (3 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Aghanim,+N">N. Aghanim</a> (17), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Altieri,+B">B. Altieri</a> (18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Amara,+A">A. Amara</a> (19), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Andreon,+S">S. Andreon</a> (20), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Auricchio,+N">N. Auricchio</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Baccigalupi,+C">C. Baccigalupi</a> (22 and 23 and 24 and 25), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Baldi,+M">M. Baldi</a> (26 and 21 and 27), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Balestra,+A">A. Balestra</a> (28), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Bardelli,+S">S. Bardelli</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Battaglia,+P">P. Battaglia</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Biviano,+A">A. Biviano</a> (23 and 22), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Bonchi,+A">A. Bonchi</a> (29), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Branchini,+E">E. Branchini</a> (30 and 31 and 20), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brescia,+M">M. Brescia</a> (32 and 33), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brinchmann,+J">J. Brinchmann</a> (34 and 35), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Camera,+S">S. Camera</a> (36 and 37 and 8), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Ca%C3%B1as-Herrera,+G">G. Ca帽as-Herrera</a> (38 and 39 and 40), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Capobianco,+V">V. Capobianco</a> (8), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Carbone,+C">C. Carbone</a> (41), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Carretero,+J">J. Carretero</a> (42 and 43), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Casas,+S">S. Casas</a> (44), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Castellano,+M">M. Castellano</a> (45), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Castignani,+G">G. Castignani</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cavuoti,+S">S. Cavuoti</a> (33 and 46), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Chambers,+K+C">K. C. Chambers</a> (47), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cimatti,+A">A. Cimatti</a> (48), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Colodro-Conde,+C">C. Colodro-Conde</a> (3), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Congedo,+G">G. Congedo</a> (49), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Conselice,+C+J">C. J. Conselice</a> (50), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Conversi,+L">L. Conversi</a> (51 and 18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Copin,+Y">Y. Copin</a> (52), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Courbin,+F">F. Courbin</a> (53 and 54), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Courtois,+H+M">H. M. Courtois</a> (55), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cropper,+M">M. Cropper</a> (56), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cuby,+J">J.-G. Cuby</a> (57 and 58), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Da+Silva,+A">A. Da Silva</a> (59 and 60), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Degaudenzi,+H">H. Degaudenzi</a> (61), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=De+Lucia,+G">G. De Lucia</a> (23), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dolding,+C">C. Dolding</a> (56), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dole,+H">H. Dole</a> (17), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Douspis,+M">M. Douspis</a> (17), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dubath,+F">F. Dubath</a> (61), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dupac,+X">X. Dupac</a> (18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dusini,+S">S. Dusini</a> (62), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Escoffier,+S">S. Escoffier</a> (63), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Farina,+M">M. Farina</a> (64), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Faustini,+F">F. Faustini</a> (45 and 29), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Ferriol,+S">S. Ferriol</a> (52), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Fotopoulou,+S">S. Fotopoulou</a> (65), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Frailis,+M">M. Frailis</a> (23), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Franceschi,+E">E. Franceschi</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Galeotta,+S">S. Galeotta</a> (23), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=George,+K">K. George</a> (66), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Gillis,+B">B. Gillis</a> (49), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Giocoli,+C">C. Giocoli</a> (21 and 27), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=G%C3%B3mez-Alvarez,+P">P. G贸mez-Alvarez</a> (67 and 18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Gracia-Carpio,+J">J. Gracia-Carpio</a> (68), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Granett,+B+R">B. R. Granett</a> (20), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Grazian,+A">A. Grazian</a> (28), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Grupp,+F">F. Grupp</a> (68 and 66), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Haugan,+S+V+H">S. V. H. Haugan</a> (69), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hoar,+J">J. Hoar</a> (18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Holmes,+W">W. Holmes</a> (70), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hormuth,+F">F. Hormuth</a> (71), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hornstrup,+A">A. Hornstrup</a> (72 and 73), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Jahnke,+K">K. Jahnke</a> (74), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Jhabvala,+M">M. Jhabvala</a> (75), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Keih%C3%A4nen,+E">E. Keih盲nen</a> (76), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kermiche,+S">S. Kermiche</a> (63), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kiessling,+A">A. Kiessling</a> (70), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kubik,+B">B. Kubik</a> (52), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kuijken,+K">K. Kuijken</a> (40), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=K%C3%BCmmel,+M">M. K眉mmel</a> (66), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kunz,+M">M. Kunz</a> (77), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kurki-Suonio,+H">H. Kurki-Suonio</a> (78 and 79), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Boulc'h,+Q+L">Q. Le Boulc'h</a> (80), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brun,+A+M+C+L">A. M. C. Le Brun</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 17 pages, 14 figures </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Solar and Stellar Astrophysics (astro-ph.SR)</span>; Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM) </div> <p class='mathjax'> We present a catalogue of more than 5000 new ultracool dwarf (UCD) candidates in the three Euclid Deep Fields in the Q1 data release. They range from late M to late T dwarfs, and include 1200 L and T dwarfs. More than 100 of them have been spectroscopically confirmed, with seven of them being T dwarfs. Our UCD selection criteria are based only on colour ($I_\mathrm{E}-Y_\mathrm{E}>2.5$). The combined requirement for optical detection and stringent signal-to-noise ratio threshold ensure a high purity of the sample, but at the expense of completeness, especially for T dwarfs. The detections range from magnitudes 19 and 24 in the near-infrared bands, and extend down to 26 in the optical band. The average surface density of detected UCDs on the sky is approximately 100 objects per $\mathrm{deg}^2$, including 20 L and T dwarfs per $\mathrm{deg}^2$. This leads to an expectation of at least 1.4 million ultracool dwarfs in the final data release of the Euclid Wide Survey, including at least 300,000 L dwarfs, and more than 2,600 T dwarfs, using the strict selection criteria from this work. We provide empirical Euclid colours as a function of spectral type, and a probability that an object with a given colour has a certain spectral type. </p> </div> </dd> <dt> <a name='item8'>[8]</a> <a href ="/abs/2503.22559" title="Abstract" id="2503.22559"> arXiv:2503.22559 </a> (cross-list from astro-ph.SR) [<a href="/pdf/2503.22559" title="Download PDF" id="pdf-2503.22559" aria-labelledby="pdf-2503.22559">pdf</a>, <a href="https://arxiv.org/html/2503.22559v1" title="View HTML" id="html-2503.22559" aria-labelledby="html-2503.22559" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2503.22559" title="Other formats" id="oth-2503.22559" aria-labelledby="oth-2503.22559">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> Euclid Quick Data Release (Q1) Ultracool dwarfs in the Euclid Deep Field North </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Mohandasan,+A">A. Mohandasan</a> (1), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Smart,+R+L">R. L. Smart</a> (2 and 3), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Reyl%C3%A9,+C">C. Reyl茅</a> (1), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brun,+V+L">V. Le Brun</a> (4), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=P%C3%A9rez-Garrido,+A">A. P茅rez-Garrido</a> (5), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Ba%C3%B1ados,+E">E. Ba帽ados</a> (6), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Goldman,+B">B. Goldman</a> (7 and 8), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Casewell,+S+L">S. L. Casewell</a> (9), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Osorio,+M+R+Z">M. R. Zapatero Osorio</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dupuy,+T">T. Dupuy</a> (11), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Rejkuba,+M">M. Rejkuba</a> (12), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Mart%C3%ADn,+E+L">E. L. Mart铆n</a> (13 and 14), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dominguez-Tagle,+C">C. Dominguez-Tagle</a> (13 and 14), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=%7B%C5%BD%7Derjal,+M">M. {沤}erjal</a> (13 and 14), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hu%C3%A9lamo,+N">N. Hu茅lamo</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Lodieu,+N">N. Lodieu</a> (15 and 14), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cruz,+P">P. Cruz</a> (10), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Rebolo,+R">R. Rebolo</a> (13 and 16 and 14), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Phillips,+M+W">M. W. Phillips</a> (11), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Zhang,+J">J.-Y. Zhang</a> (13 and 14), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Aghanim,+N">N. Aghanim</a> (17), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Altieri,+B">B. Altieri</a> (18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Amara,+A">A. Amara</a> (19), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Andreon,+S">S. Andreon</a> (20), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Auricchio,+N">N. Auricchio</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Baccigalupi,+C">C. Baccigalupi</a> (22 and 23 and 24 and 25), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Baldi,+M">M. Baldi</a> (26 and 21 and 27), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Balestra,+A">A. Balestra</a> (28), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Bardelli,+S">S. Bardelli</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Battaglia,+P">P. Battaglia</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Biviano,+A">A. Biviano</a> (23 and 22), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Bonchi,+A">A. Bonchi</a> (29), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Branchini,+E">E. Branchini</a> (30 and 31 and 20), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brescia,+M">M. Brescia</a> (32 and 33), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brinchmann,+J">J. Brinchmann</a> (34 and 35), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Camera,+S">S. Camera</a> (36 and 37 and 2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Ca%C3%B1as-Herrera,+G">G. Ca帽as-Herrera</a> (38 and 39 and 40), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Capobianco,+V">V. Capobianco</a> (2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Carbone,+C">C. Carbone</a> (41), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Carretero,+J">J. Carretero</a> (42 and 43), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Casas,+S">S. Casas</a> (44), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Castellano,+M">M. Castellano</a> (45), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Castignani,+G">G. Castignani</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cavuoti,+S">S. Cavuoti</a> (33 and 46), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Chambers,+K+C">K. C. Chambers</a> (47), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cimatti,+A">A. Cimatti</a> (48), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Colodro-Conde,+C">C. Colodro-Conde</a> (13), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Congedo,+G">G. Congedo</a> (11), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Conselice,+C+J">C. J. Conselice</a> (49), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Conversi,+L">L. Conversi</a> (50 and 18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Copin,+Y">Y. Copin</a> (51), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Costille,+A">A. Costille</a> (4), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Courbin,+F">F. Courbin</a> (52 and 53), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Courtois,+H+M">H. M. Courtois</a> (54), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Cropper,+M">M. 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Escoffier</a> (60), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Farina,+M">M. Farina</a> (61), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Faustini,+F">F. Faustini</a> (45 and 29), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Ferriol,+S">S. Ferriol</a> (51), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Fotopoulou,+S">S. Fotopoulou</a> (62), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Frailis,+M">M. Frailis</a> (23), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Franceschi,+E">E. Franceschi</a> (21), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Galeotta,+S">S. Galeotta</a> (23), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=George,+K">K. George</a> (63), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Gillard,+W">W. Gillard</a> (60), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Gillis,+B">B. Gillis</a> (11), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Giocoli,+C">C. Giocoli</a> (21 and 27), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Gracia-Carpio,+J">J. Gracia-Carpio</a> (64), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Granett,+B+R">B. R. Granett</a> (20), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Grazian,+A">A. Grazian</a> (28), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Grupp,+F">F. Grupp</a> (64 and 63), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Haugan,+S+V+H">S. V. H. Haugan</a> (65), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hoar,+J">J. Hoar</a> (18), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Holmes,+W">W. Holmes</a> (66), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hook,+I+M">I. M. Hook</a> (67), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hormuth,+F">F. Hormuth</a> (68), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Hornstrup,+A">A. Hornstrup</a> (69 and 70), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Jahnke,+K">K. Jahnke</a> (6), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Jhabvala,+M">M. Jhabvala</a> (71), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Keih%C3%A4nen,+E">E. Keih盲nen</a> (72), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kermiche,+S">S. Kermiche</a> (60), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kiessling,+A">A. Kiessling</a> (66), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kubik,+B">B. Kubik</a> (51), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kuijken,+K">K. Kuijken</a> (40), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=K%C3%BCmmel,+M">M. K眉mmel</a> (63), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kunz,+M">M. Kunz</a> (73), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Kurki-Suonio,+H">H. Kurki-Suonio</a> (74 and 75), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Boulc'h,+Q+L">Q. Le Boulc'h</a> (76), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brun,+A+M+C+L">A. M. C. Le Brun</a> (77), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Mignant,+D+L">D. Le Mignant</a> (4), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Ligori,+S">S. Ligori</a> (2), <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Lilje,+P+B">P. B. Lilje</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 14 pages, 9 figures, 2 tables </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Solar and Stellar Astrophysics (astro-ph.SR)</span>; Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM) </div> <p class='mathjax'> Ultracool dwarfs (UCDs) encompass the lowest mass stars and brown dwarfs, defining the stellar substellar boundary. They have significant potential for advancing the understanding of substellar physics; however, these objects are challenging to detect due to their low luminosity. The wide coverage and deep sensitivity of the Euclid survey will increase the number of confirmed and well characterised UCDs by several orders of magnitude. In this study, we take advantage of the Euclid Quick Data Release (Q1) and in particular we look in detail at the known and new UCDs in the Euclid Deep Field North (22.9 deg2 down to JE = 24.5 mag), to understand the advantages of using the slitless Euclid spectroscopy. We compile a comparison sample of known UCDs and use their spectra to demonstrate the capability of Euclid to derive spectral types using a template matching method. This method is then applied to the spectra of the newly identified candidates. We confirm that 33 of these candidates are new UCDs, with spectral types ranging from M7 to T1 and JE = 17 to 21 mag. We look at their locus in colour colour diagrams and compare them with the expected colours of QSOs. A machine readable catalogue is provided for further study, containing both the comparison sample and the newly identified UCDs, along with their spectral classifications where the Q1 spectra quality allows for confident determination </p> </div> </dd> </dl> <dl id='articles'> <h3>Replacement submissions (showing 2 of 2 entries)</h3> <dt> <a name='item9'>[9]</a> <a href ="/abs/2405.08388" title="Abstract" id="2405.08388"> arXiv:2405.08388 </a> (replaced) [<a href="/pdf/2405.08388" title="Download PDF" id="pdf-2405.08388" aria-labelledby="pdf-2405.08388">pdf</a>, <a href="https://arxiv.org/html/2405.08388v2" title="View HTML" id="html-2405.08388" aria-labelledby="html-2405.08388" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2405.08388" title="Other formats" id="oth-2405.08388" aria-labelledby="oth-2405.08388">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> The Radio and Microwave Sky as Seen by Juno on its Mission to Jupiter </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Anderson,+C">Christopher Anderson</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Berger,+P">Philippe Berger</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Chang,+T">Tzu-Ching Chang</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Dor%C3%A9,+O">Olivier Dor茅</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Brown,+S">Shannon Brown</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Levin,+S">Steve Levin</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Seiffert,+M">Michael Seiffert</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> Minor changes to the text. Added over-hat estimator notation to equations in section 3 for clarity. Fixed typo in equation 15. Re-computed the noise and gain solutions for R1 and R2 at higher map resolution, reducing errors. Updated estimates of correlated map-space errors for all bands and verified them against simulations (figure 10). 17 pages, 14 figures </div> <div class='list-journal-ref'><span class='descriptor'>Journal-ref:</span> ApJ 982 118 (2025) </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Instrumentation and Methods for Astrophysics (astro-ph.IM)</span>; Cosmology and Nongalactic Astrophysics (astro-ph.CO) </div> <p class='mathjax'> We present six nearly full-sky maps made from data taken by radiometers on the Juno satellite during its 5-year flight to Jupiter. The maps represent integrated emission over $\sim 4\%$ passbands spaced approximately in octaves between 600 MHz and 21.9 GHz. Long time-scale offset drifts are removed in all bands, and, for the two lowest frequency bands, gain drifts are also removed from the maps via a self-calibration algorithm similar to the NPIPE pipeline used by the Planck collaboration. We show that, after this solution is applied, statistical noise in the maps is consistent with thermal radiometer noise and expected levels of correlated noise on the gain and noise drift solutions. We verify our map solutions with several consistency tests and end-to-end simulations. We also estimate the level of systematic pixelization noise and polarization leakage via simulations. </p> </div> </dd> <dt> <a name='item10'>[10]</a> <a href ="/abs/2502.09810" title="Abstract" id="2502.09810"> arXiv:2502.09810 </a> (replaced) [<a href="/pdf/2502.09810" title="Download PDF" id="pdf-2502.09810" aria-labelledby="pdf-2502.09810">pdf</a>, <a href="https://arxiv.org/html/2502.09810v2" title="View HTML" id="html-2502.09810" aria-labelledby="html-2502.09810" rel="noopener noreferrer" target="_blank">html</a>, <a href="/format/2502.09810" title="Other formats" id="oth-2502.09810" aria-labelledby="oth-2502.09810">other</a>] </dt> <dd> <div class='meta'> <div class='list-title mathjax'><span class='descriptor'>Title:</span> $螞$CDM and early dark energy in latent space: a data-driven parametrization of the CMB temperature power spectrum </div> <div class='list-authors'><a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Piras,+D">Davide Piras</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Herold,+L">Laura Herold</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Lucie-Smith,+L">Luisa Lucie-Smith</a>, <a href="https://arxiv.org/search/astro-ph?searchtype=author&query=Komatsu,+E">Eiichiro Komatsu</a></div> <div class='list-comments mathjax'><span class='descriptor'>Comments:</span> 18 pages, 12 figures. Minor changes to match version published in PRD </div> <div class='list-subjects'><span class='descriptor'>Subjects:</span> <span class="primary-subject">Cosmology and Nongalactic Astrophysics (astro-ph.CO)</span>; Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG) </div> <p class='mathjax'> Finding the best parametrization for cosmological models in the absence of first-principle theories is an open question. We propose a data-driven parametrization of cosmological models given by the disentangled 'latent' representation of a variational autoencoder (VAE) trained to compress cosmic microwave background (CMB) temperature power spectra. We consider a broad range of $\Lambda$CDM and beyond-$\Lambda$CDM cosmologies with an additional early dark energy (EDE) component. We show that these spectra can be compressed into 5 ($\Lambda$CDM) or 8 (EDE) independent latent parameters, as expected when using temperature power spectra alone, and which reconstruct spectra at an accuracy well within the Planck errors. These latent parameters have a physical interpretation in terms of well-known features of the CMB temperature spectrum: these include the position, height and even-odd modulation of the acoustic peaks, as well as the gravitational lensing effect. The VAE also discovers one latent parameter which entirely isolates the EDE effects from those related to $\Lambda$CDM parameters, thus revealing a previously unknown degree of freedom in the CMB temperature power spectrum. We further showcase how to place constraints on the latent parameters using Planck data as typically done for cosmological parameters, obtaining latent values consistent with previous $\Lambda$CDM and EDE cosmological constraints. Our work demonstrates the potential of a data-driven reformulation of current beyond-$\Lambda$CDM phenomenological models into the independent degrees of freedom to which the data observables are sensitive. </p> </div> </dd> </dl> <div class='paging'>Total of 10 entries </div> <div class='morefewer'>Showing up to 2000 entries per page: <a href=/list/astro-ph.IM/new?skip=0&show=1000 rel="nofollow"> fewer</a> | <span style="color: #454545">more</span> | <span style="color: #454545">all</span> </div> </div> </div> </div> </main> <footer style="clear: both;"> <div class="columns is-desktop" role="navigation" aria-label="Secondary" style="margin: -0.75em -0.75em 0.75em -0.75em">  <div class="column" style="padding: 0;"> <div class="columns"> <div class="column"> <ul style="list-style: none; line-height: 2;"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul style="list-style: none; line-height: 2;"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column" style="padding: 0;"> <div class="columns"> <div class="column"> <ul style="list-style: none; 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