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breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Burningham%2C+B&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Burningham%2C+B&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Burningham%2C+B&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/2411.16577">arXiv:2411.16577</a> <span> [<a href="https://arxiv.org/pdf/2411.16577">pdf</a>, <a href="https://arxiv.org/format/2411.16577">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> The JWST Weather Report from the Isolated Exoplanet Analog SIMP 0136+0933: Pressure-Dependent Variability Driven by Multiple Mechanisms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=McCarthy%2C+A+M">Allison M. McCarthy</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Muirhead%2C+P+S">Philip S. Muirhead</a>, <a href="/search/?searchtype=author&query=Biller%2C+B+A">Beth A. Biller</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J">Jacqueline Faherty</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Calamari%2C+E">Emily Calamari</a>, <a href="/search/?searchtype=author&query=Cowan%2C+N+B">Nicolas B. Cowan</a>, <a href="/search/?searchtype=author&query=Cruz%2C+K+L">Kelle L. Cruz</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E">Eileen Gonzales</a>, <a href="/search/?searchtype=author&query=Limbach%2C+M+A">Mary Anne Limbach</a>, <a href="/search/?searchtype=author&query=Liu%2C+P">Pengyu Liu</a>, <a href="/search/?searchtype=author&query=Nasedkin%2C+E">Evert Nasedkin</a>, <a href="/search/?searchtype=author&query=Suarez%2C+G">Genaro Suarez</a>, <a href="/search/?searchtype=author&query=Tan%2C+X">Xianyu Tan</a>, <a href="/search/?searchtype=author&query=O%27Toole%2C+C">Cian O'Toole</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Whiteford%2C+N">Niall Whiteford</a>, <a href="/search/?searchtype=author&query=Zhou%2C+Y">Yifan Zhou</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="2411.16577v1-abstract-short" style="display: inline;"> Isolated planetary-mass objects share their mass range with planets but do not orbit a star. They lack the necessary mass to support fusion in their cores and thermally radiate their heat from formation as they cool, primarily at infrared wavelengths. Many isolated planetary-mass objects show variations in their infrared brightness consistent with non-uniform atmospheric features modulated by thei… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.16577v1-abstract-full').style.display = 'inline'; document.getElementById('2411.16577v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.16577v1-abstract-full" style="display: none;"> Isolated planetary-mass objects share their mass range with planets but do not orbit a star. They lack the necessary mass to support fusion in their cores and thermally radiate their heat from formation as they cool, primarily at infrared wavelengths. Many isolated planetary-mass objects show variations in their infrared brightness consistent with non-uniform atmospheric features modulated by their rotation. SIMP J013656.5+093347.3 is a rapidly rotating isolated planetary-mass object, and previous infrared monitoring suggests complex atmospheric features rotating in and out of view. The physical nature of these features is not well understood, with clouds, temperature variations, thermochemical instabilities, and infrared-emitting aurora all proposed as contributing mechanisms. Here we report JWST time-resolved low-resolution spectroscopy from 0.8 - 11 micron of SIMP J013656.5+093347.3 which supports the presence of three specific features in the atmosphere: clouds, hot spots, and changing carbon chemistry. We show that no single mechanism can explain the variations in the time-resolved spectra. When combined with previous studies of this object indicating patchy clouds and aurorae, these measurements reveal the rich complexity of the atmosphere of SIMP J013656.5+093347.3. Gas giant planets in the solar system, specifically Jupiter and Saturn, also have multiple cloud layers and high-altitude hot spots, suggesting these phenomena are also present in worlds both within and beyond our solar-system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.16577v1-abstract-full').style.display = 'none'; document.getElementById('2411.16577v1-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted to 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/2411.14541">arXiv:2411.14541</a> <span> [<a href="https://arxiv.org/pdf/2411.14541">pdf</a>, <a href="https://arxiv.org/format/2411.14541">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="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Protosolar D-to-H abundance and one part-per-billion PH$_{3}$ in the coldest brown dwarf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Rowland%2C+M+J">Melanie J. Rowland</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Miles%2C+B+E">Brittany E. Miles</a>, <a href="/search/?searchtype=author&query=Su%C3%A1rez%2C+G">Genaro Su谩rez</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Skemer%2C+A+J">Andrew J. Skemer</a>, <a href="/search/?searchtype=author&query=Beiler%2C+S+A">Samuel A. Beiler</a>, <a href="/search/?searchtype=author&query=Line%2C+M+R">Michael R. Line</a>, <a href="/search/?searchtype=author&query=Bjoraker%2C+G+L">Gordon L. Bjoraker</a>, <a href="/search/?searchtype=author&query=Fortney%2C+J+J">Jonathan J. Fortney</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Merchan%2C+S+A">Sherelyn Alejandro Merchan</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</a>, <a href="/search/?searchtype=author&query=Gharib-Nezhad%2C+E">Ehsan Gharib-Nezhad</a>, <a href="/search/?searchtype=author&query=Batalha%2C+N">Natasha Batalha</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Schneider%2C+A+C">Adam C. Schneider</a>, <a href="/search/?searchtype=author&query=Geballe%2C+T+R">T. R. Geballe</a>, <a href="/search/?searchtype=author&query=Carter%2C+A">Aarynn Carter</a>, <a href="/search/?searchtype=author&query=Allers%2C+K">Katelyn Allers</a>, <a href="/search/?searchtype=author&query=Mang%2C+J">James Mang</a>, <a href="/search/?searchtype=author&query=Apai%2C+D">D谩niel Apai</a> , et al. (2 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.14541v2-abstract-short" style="display: inline;"> The coldest Y spectral type brown dwarfs are similar in mass and temperature to cool and warm ($\sim$200 -- 400 K) giant exoplanets. We can therefore use their atmospheres as proxies for planetary atmospheres, testing our understanding of physics and chemistry for these complex, cool worlds. At these cold temperatures, their atmospheres are cold enough for water clouds to form, and chemical timesc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.14541v2-abstract-full').style.display = 'inline'; document.getElementById('2411.14541v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.14541v2-abstract-full" style="display: none;"> The coldest Y spectral type brown dwarfs are similar in mass and temperature to cool and warm ($\sim$200 -- 400 K) giant exoplanets. We can therefore use their atmospheres as proxies for planetary atmospheres, testing our understanding of physics and chemistry for these complex, cool worlds. At these cold temperatures, their atmospheres are cold enough for water clouds to form, and chemical timescales increase, increasing the likelihood of disequilibrium chemistry compared to warmer classes of planets. JWST observations are revolutionizing the characterization of these worlds with high signal-to-noise, moderate resolution near- and mid-infrared spectra. The spectra have been used to measure the abundances of prominent species like water, methane, and ammonia; species that trace chemical reactions like carbon monoxide; and even isotopologues of carbon monoxide and ammonia. Here, we present atmospheric retrieval results using both published fixed-slit (GTO program 1230) and new averaged time series observations (GO program 2327) of the coldest known Y dwarf, WISE 0855-0714 (using NIRSpec G395M spectra), which has an effective temperature of $\sim$ 264 K. We present a detection of deuterium in an atmosphere outside of the solar system via a relative measurement of deuterated methane (CH$_{3}$D) and standard methane. From this, we infer the D/H ratio of a substellar object outside the solar system for the first time. We also present a well-constrained part-per-billion abundance of phosphine (PH$_{3}$). We discuss our interpretation of these results and the implications for brown dwarf and giant exoplanet formation and evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.14541v2-abstract-full').style.display = 'none'; document.getElementById('2411.14541v2-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 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">17 pages, 7 figures, accepted to 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/2409.03706">arXiv:2409.03706</a> <span> [<a href="https://arxiv.org/pdf/2409.03706">pdf</a>, <a href="https://arxiv.org/format/2409.03706">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="Earth and Planetary Astrophysics">astro-ph.EP</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/stae2102">10.1093/mnras/stae2102 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Gaia Ultracool Dwarf Sample -- IV. GTC/OSIRIS optical spectra of Gaia late-M and L dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cooper%2C+W+J">W. J. Cooper</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Folkes%2C+S+L">S. L. Folkes</a>, <a href="/search/?searchtype=author&query=Caballero%2C+J+A">J. A. Caballero</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Ortiz%2C+M+C+G">M. C. G谩lvez Ortiz</a>, <a href="/search/?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/?searchtype=author&query=Kirkpatrick%2C+J+D">J. D. Kirkpatrick</a>, <a href="/search/?searchtype=author&query=Sarro%2C+L+M">L. M. Sarro</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Cabrera-Lavers%2C+A">A. Cabrera-Lavers</a>, <a href="/search/?searchtype=author&query=Tremblay%2C+P+E">P. E. Tremblay</a>, <a href="/search/?searchtype=author&query=Reyl%C3%A9%2C+C">C. Reyl茅</a>, <a href="/search/?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/?searchtype=author&query=Cook%2C+N+J">N. J. Cook</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+F">J. F. Faherty</a>, <a href="/search/?searchtype=author&query=Garc%C3%ADa-%C3%81lvarez%2C+D">D. Garc铆a-脕lvarez</a>, <a href="/search/?searchtype=author&query=Montes%2C+D">D. Montes</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Rajpurohit%2C+A+S">A. S. Rajpurohit</a>, <a href="/search/?searchtype=author&query=Shi%2C+J">J. Shi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.03706v2-abstract-short" style="display: inline;"> As part of our comprehensive, ongoing characterisation of the low-mass end of the main sequence in the Solar neighbourhood, we used the OSIRIS instrument at the 10.4 m Gran Telescopio Canarias to acquire low- and mid-resolution (R$\approx$300 and R$\approx$2500) optical spectroscopy of 53 late-M and L ultracool dwarfs. Most of these objects are known but poorly investigated and lacking complete ki… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.03706v2-abstract-full').style.display = 'inline'; document.getElementById('2409.03706v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.03706v2-abstract-full" style="display: none;"> As part of our comprehensive, ongoing characterisation of the low-mass end of the main sequence in the Solar neighbourhood, we used the OSIRIS instrument at the 10.4 m Gran Telescopio Canarias to acquire low- and mid-resolution (R$\approx$300 and R$\approx$2500) optical spectroscopy of 53 late-M and L ultracool dwarfs. Most of these objects are known but poorly investigated and lacking complete kinematics. We measured spectral indices, determined spectral types (six of which are new) and inferred effective temperature and surface gravity from BT-Settl synthetic spectra fits for all objects. We were able to measure radial velocities via line centre fitting and cross correlation for 46 objects, 29 of which lacked previous radial velocity measurements. Using these radial velocities in combination with the latest Gaia DR3 data, we also calculated Galactocentric space velocities. From their kinematics, we identified two candidates outside of the thin disc and four in young stellar kinematic groups. Two further ultracool dwarfs are apparently young field objects: 2MASSW J1246467$+$402715 (L4$尾$), which has a potential, weak lithium absorption line, and G 196$-$3B (L3$尾$), which was already known as young due to its well-studied primary companion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.03706v2-abstract-full').style.display = 'none'; document.getElementById('2409.03706v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">33 pages, 14 figures, Accepted by MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.01694">arXiv:2407.01694</a> <span> [<a href="https://arxiv.org/pdf/2407.01694">pdf</a>, <a href="https://arxiv.org/format/2407.01694">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="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Retrieving Young Cloudy L-Dwarfs: A Nearby Planetary-Mass Companion BD+60 1417B and Its Isolated Red Twin W0047 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Phillips%2C+C+L">Caprice L. Phillips</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E">Eileen Gonzales</a>, <a href="/search/?searchtype=author&query=Griffith%2C+E+J">Emily J. Griffith</a>, <a href="/search/?searchtype=author&query=Merchan%2C+S+A">Sherelyn Alejandro Merchan</a>, <a href="/search/?searchtype=author&query=Calamari%2C+E">Emily Calamari</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Whiteford%2C+N">Niall Whiteford</a>, <a href="/search/?searchtype=author&query=Gaarn%2C+J">Josefine Gaarn</a>, <a href="/search/?searchtype=author&query=Ilyin%2C+I">Ilya Ilyin</a>, <a href="/search/?searchtype=author&query=Strassmeier%2C+K">Klaus Strassmeier</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="2407.01694v1-abstract-short" style="display: inline;"> We present an atmospheric retrieval analysis on a set of young, cloudy, red L-dwarfs -- CWISER J124332.12+600126.2 and WISEP J004701.06+680352.1 -- using the \textit{Brewster} retrieval framework. We also present the first elemental abundance measurements of the young K-dwarf (K0) host star, BD+60 1417 using high resolution~(R = 50,000) spectra taken with PEPSI/LBT. In the complex cloudy L-dwarf r… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.01694v1-abstract-full').style.display = 'inline'; document.getElementById('2407.01694v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.01694v1-abstract-full" style="display: none;"> We present an atmospheric retrieval analysis on a set of young, cloudy, red L-dwarfs -- CWISER J124332.12+600126.2 and WISEP J004701.06+680352.1 -- using the \textit{Brewster} retrieval framework. We also present the first elemental abundance measurements of the young K-dwarf (K0) host star, BD+60 1417 using high resolution~(R = 50,000) spectra taken with PEPSI/LBT. In the complex cloudy L-dwarf regime the emergence of condensate cloud species complicates retrieval analysis when only near-infrared data is available. We find that for both L dwarfs in this work, despite testing three different thermal profile parameterizations we are unable to constrain reliable abundance measurements and thus the C/O ratio. While we can not conclude what the abundances are, we can conclude that the data strongly favor a cloud model over a cloudless model. We note that the difficulty in retrieval constraints persists regardless of the signal to noise of the data examined (S/N $\sim$ 10 for CWISER J124332.12+600126.2 and~40 for WISEP J004701.06+680352.1). The results presented in this work provide valuable lessons about retrieving young, low-surface gravity, cloudy L-dwarfs. This work provides continued evidence of missing information in models and the crucial need for JWST to guide and inform retrieval analysis in this regime. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.01694v1-abstract-full').style.display = 'none'; document.getElementById('2407.01694v1-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 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">Accepted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.06493">arXiv:2406.06493</a> <span> [<a href="https://arxiv.org/pdf/2406.06493">pdf</a>, <a href="https://arxiv.org/format/2406.06493">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="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Probing the Heights and Depths of Y Dwarf Atmospheres: A Retrieval Analysis of the JWST Spectral Energy Distribution of WISE J035934.06$-$540154.6 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kothari%2C+H">Harshil Kothari</a>, <a href="/search/?searchtype=author&query=Cushing%2C+M+C">Michael C. Cushing</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Beiler%2C+S+A">Samuel A. Beiler</a>, <a href="/search/?searchtype=author&query=Kirkpatrick%2C+J+D">J. Davy Kirkpatrick</a>, <a href="/search/?searchtype=author&query=Schneider%2C+A+C">Adam C. Schneider</a>, <a href="/search/?searchtype=author&query=Mukherjee%2C+S">Sagnick Mukherjee</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">Mark S. Marley</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.06493v1-abstract-short" style="display: inline;"> We present an atmospheric retrieval analysis of the Y0 brown dwarf WISE J035934.06$-$540154.6 using the low-resolution 0.96--12 $渭$m JWST spectrum presented in \citet{Beiler_2023}. We obtain volume number mixing ratios of the major gas-phase absorbers (H$_2$O, CH$_4$, CO, CO$_2$, PH$_3$, and H$_2$S) that are 3--5$\times$ more precise than previous work that used HST spectra. We also find an order-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.06493v1-abstract-full').style.display = 'inline'; document.getElementById('2406.06493v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.06493v1-abstract-full" style="display: none;"> We present an atmospheric retrieval analysis of the Y0 brown dwarf WISE J035934.06$-$540154.6 using the low-resolution 0.96--12 $渭$m JWST spectrum presented in \citet{Beiler_2023}. We obtain volume number mixing ratios of the major gas-phase absorbers (H$_2$O, CH$_4$, CO, CO$_2$, PH$_3$, and H$_2$S) that are 3--5$\times$ more precise than previous work that used HST spectra. We also find an order-of-magnitude improvement in the precision of the retrieved thermal profile, a direct result of the broad wavelength coverage of the JWST data. We used the retrieved thermal profile and surface gravity to generate a grid of chemical forward models with varying metallicity, (C/O)$_\textrm{atm}$, and strengths of vertical mixing as encapsulated by the eddy diffusion coefficient $K_\textrm{zz}$. Comparison of the retrieved abundances with this grid of models suggests that the deep atmosphere of WISE 0359$-$54 shows signs of vigorous vertical mixing with $K_\textrm{zz}=10^9$ [cm$^{2}$ s$^{-1}$]. To test the sensitivity of these results to our 5-knot spline thermal profile model, we performed a second retrieval using the \citet{Madhusudhan_2009} thermal profile model. While the results of the two retrievals generally agree well, we do find differences between the retrieved values of mass and volume number mixing ratio of H$_2$S with fractional differences of the median values of $-$0.64 and $-$0.10, respectively. In addition, the 5-knot thermal profile is consistently warmer at pressure between 1 and 70 bar. Nevertheless, our results underscore the power that the broad-wavelength infrared spectra obtainable with the James Webb Space Telescope have to characterize the atmospheres of cool brown dwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.06493v1-abstract-full').style.display = 'none'; document.getElementById('2406.06493v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.10977">arXiv:2404.10977</a> <span> [<a href="https://arxiv.org/pdf/2404.10977">pdf</a>, <a href="https://arxiv.org/format/2404.10977">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="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/s41586-024-07190-w">10.1038/s41586-024-07190-w <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Methane Emission From a Cool Brown Dwarf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Gagn%C3%A9%2C+J">Jonathan Gagn茅</a>, <a href="/search/?searchtype=author&query=Su%C3%A1rez%2C+G">Genaro Su谩rez</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Merchan%2C+S+A">Sherelyn Alejandro Merchan</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Rowland%2C+M">Melanie Rowland</a>, <a href="/search/?searchtype=author&query=Lacy%2C+B">Brianna Lacy</a>, <a href="/search/?searchtype=author&query=Kiman%2C+R">Rocio Kiman</a>, <a href="/search/?searchtype=author&query=Caselden%2C+D">Dan Caselden</a>, <a href="/search/?searchtype=author&query=Kirkpatrick%2C+J+D">J. Davy Kirkpatrick</a>, <a href="/search/?searchtype=author&query=Meisner%2C+A">Aaron Meisner</a>, <a href="/search/?searchtype=author&query=Schneider%2C+A+C">Adam C. Schneider</a>, <a href="/search/?searchtype=author&query=Kuchner%2C+M+J">Marc Jason Kuchner</a>, <a href="/search/?searchtype=author&query=Gagliuffi%2C+D+C+B">Daniella Carolina Bardalez Gagliuffi</a>, <a href="/search/?searchtype=author&query=Beichman%2C+C">Charles Beichman</a>, <a href="/search/?searchtype=author&query=Eisenhardt%2C+P">Peter Eisenhardt</a>, <a href="/search/?searchtype=author&query=Gelino%2C+C+R">Christopher R. Gelino</a>, <a href="/search/?searchtype=author&query=Gharib-Nezhad%2C+E">Ehsan Gharib-Nezhad</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E">Eileen Gonzales</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">Federico Marocco</a>, <a href="/search/?searchtype=author&query=Rothermich%2C+A+J">Austin James Rothermich</a>, <a href="/search/?searchtype=author&query=Whiteford%2C+N">Niall Whiteford</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="2404.10977v1-abstract-short" style="display: inline;"> Beyond our solar system, aurorae have been inferred from radio observations of isolated brown dwarfs (e.g. Hallinan et al. 2006; Kao et al. 2023). Within our solar system, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H3+ and methane. Isolated brown dwarfs with auroral signatures in the radio have been searched for correspond… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10977v1-abstract-full').style.display = 'inline'; document.getElementById('2404.10977v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.10977v1-abstract-full" style="display: none;"> Beyond our solar system, aurorae have been inferred from radio observations of isolated brown dwarfs (e.g. Hallinan et al. 2006; Kao et al. 2023). Within our solar system, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H3+ and methane. Isolated brown dwarfs with auroral signatures in the radio have been searched for corresponding infrared features but have only had null detections (e.g. Gibbs et al. 2022). CWISEP J193518.59-154620.3. (W1935 for short) is an isolated brown dwarf with a temperature of ~482 K. Here we report JWST observations of strong methane emission from W1935 at 3.326 microns. Atmospheric modeling leads us to conclude that a temperature inversion of ~300 K centered at 1-10 millibar replicates the feature. This represents an atmospheric temperature inversion for a Jupiter-like atmosphere without irradiation from a host star. A plausible explanation for the strong inversion is heating by auroral processes, although other internal and/or external dynamical processes cannot be ruled out. The best fit model rules out the contribution of H3+ emission which is prominent in solar system gas giants however this is consistent with rapid destruction of H3+ at the higher pressure where the W1935 emission originates (e.g. Helling et al. 2019). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10977v1-abstract-full').style.display = 'none'; document.getElementById('2404.10977v1-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 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 in Nature 9 February 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/2402.05345">arXiv:2402.05345</a> <span> [<a href="https://arxiv.org/pdf/2402.05345">pdf</a>, <a href="https://arxiv.org/format/2402.05345">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="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> High-Precision Atmospheric Constraints for a Cool T Dwarf from JWST Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Hood%2C+C+E">Callie E. Hood</a>, <a href="/search/?searchtype=author&query=Mukherjee%2C+S">Sagnick Mukherjee</a>, <a href="/search/?searchtype=author&query=Fortney%2C+J+J">Jonathan J. Fortney</a>, <a href="/search/?searchtype=author&query=Line%2C+M+R">Michael R. Line</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Merchan%2C+S+A">Sherelyn Alejandro Merchan</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Su%C3%A1rez%2C+G">Genaro Su谩rez</a>, <a href="/search/?searchtype=author&query=Kiman%2C+R">Rocio Kiman</a>, <a href="/search/?searchtype=author&query=Gagn%C3%A9%2C+J">Jonathan Gagn茅</a>, <a href="/search/?searchtype=author&query=Beichman%2C+C+A">Charles A. Beichman</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Gagliuffi%2C+D+B">Daniella Bardalez Gagliuffi</a>, <a href="/search/?searchtype=author&query=Meisner%2C+A+M">Aaron M. Meisner</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E+C">Eileen C. Gonzales</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="2402.05345v1-abstract-short" style="display: inline;"> We present observations of the T8 dwarf 2MASS 0415-0935 with JWST's NIRSpec spectrograph using the G395H grating ($\sim$ 2.87 - 5.14 $渭$m). We perform the first atmospheric retrieval analysis at the maximum spectral resolution of NIRSpec (R$\sim$2700) and combine the spectrum with previous observations to study the 0.9-20 $渭$m spectral energy distribution. We obtain precise constraints on chemical… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.05345v1-abstract-full').style.display = 'inline'; document.getElementById('2402.05345v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.05345v1-abstract-full" style="display: none;"> We present observations of the T8 dwarf 2MASS 0415-0935 with JWST's NIRSpec spectrograph using the G395H grating ($\sim$ 2.87 - 5.14 $渭$m). We perform the first atmospheric retrieval analysis at the maximum spectral resolution of NIRSpec (R$\sim$2700) and combine the spectrum with previous observations to study the 0.9-20 $渭$m spectral energy distribution. We obtain precise constraints on chemical abundances ($\sim$0.02 dex) for a number of species which complicate our understanding of disequilibrium chemistry, particularly for CO$_{2}$ and PH$_{3}$. Furthermore, we measure a $^{12}$CO/$^{13}$CO ratio of $\sim 97^{+9}_{-8}$, making 2MASS 0415-0935 the coldest ($\sim 760$ K) substellar object outside of our solar system with a measured $^{12}$CO/$^{13}$CO ratio. This work shows promise for similar observations with JWST to provide precise abundances of major chemical species as well as isotopologues, allowing for new tests of our understanding of the formation and atmospheres of substellar objects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.05345v1-abstract-full').style.display = 'none'; document.getElementById('2402.05345v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">28 pages, 10 figures. Submitted to Nature Astronomy on Oct. 5th, 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/2401.11038">arXiv:2401.11038</a> <span> [<a href="https://arxiv.org/pdf/2401.11038">pdf</a>, <a href="https://arxiv.org/format/2401.11038">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="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Predicting Cloud Conditions in Substellar Mass Objects Using Ultracool Dwarf Companions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Calamari%2C+E">Emily Calamari</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Gemma%2C+M+E">Marina E. Gemma</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Rothermich%2C+A">Austin Rothermich</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="2401.11038v1-abstract-short" style="display: inline;"> We present results from conducting a theoretical chemical analysis of a sample of benchmark companion brown dwarfs whose primary star is of type F, G or K. We summarize the entire known sample of these types of companion systems, termed "compositional benchmarks", that are present in the literature or recently published as key systems of study in order to best understand brown dwarf chemistry and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.11038v1-abstract-full').style.display = 'inline'; document.getElementById('2401.11038v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.11038v1-abstract-full" style="display: none;"> We present results from conducting a theoretical chemical analysis of a sample of benchmark companion brown dwarfs whose primary star is of type F, G or K. We summarize the entire known sample of these types of companion systems, termed "compositional benchmarks", that are present in the literature or recently published as key systems of study in order to best understand brown dwarf chemistry and condensate formation. Via mass balance and stoichiometric calculations, we predict a median brown dwarf atmospheric oxygen sink of $17.8^{+1.7}_{-2.3}\%$ by utilizing published stellar abundances in the local solar neighborhood. Additionally, we predict a silicate condensation sequence such that atmospheres with bulk Mg/Si $\lesssim$ 0.9 will form enstatite (MgSiO$_3$) and quartz (SiO$_2$) clouds and atmospheres with bulk Mg/Si $\gtrsim$ 0.9 will form enstatite and forsterite (Mg$_2$SiO$_4$) clouds. Implications of these results on C/O ratio trends in substellar mass objects and utility of these predictions in future modeling work are discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.11038v1-abstract-full').style.display = 'none'; document.getElementById('2401.11038v1-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 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">20 pages, 2 tables, 4 figures. Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.10188">arXiv:2309.10188</a> <span> [<a href="https://arxiv.org/pdf/2309.10188">pdf</a>, <a href="https://arxiv.org/format/2309.10188">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Atmospheric Retrieval of L Dwarfs: Benchmarking Results and Characterizing the Young Planetary Mass Companion HD 106906 b in the Near-Infrared </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Adams%2C+A+D">Arthur D. Adams</a>, <a href="/search/?searchtype=author&query=Meyer%2C+M+R">Michael R. Meyer</a>, <a href="/search/?searchtype=author&query=Howe%2C+A+R">Alex R. Howe</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Daemgen%2C+S">Sebastian Daemgen</a>, <a href="/search/?searchtype=author&query=Fortney%2C+J">Jonathan Fortney</a>, <a href="/search/?searchtype=author&query=Line%2C+M">Mike Line</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</a>, <a href="/search/?searchtype=author&query=Quanz%2C+S+P">Sascha P. Quanz</a>, <a href="/search/?searchtype=author&query=Todorov%2C+K">Kamen Todorov</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="2309.10188v1-abstract-short" style="display: inline;"> We present model constraints on the atmospheric structure of HD 106906 b, a planetary-mass companion orbiting at a ~700 AU projected separation around a 15 Myr-old stellar binary, using the APOLLO retrieval code on spectral data spanning 1.1-2.5 $渭$m. C/O ratios can provide evidence for companion formation pathways, as such pathways are ambiguous both at wide separations and at star-to-companion m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.10188v1-abstract-full').style.display = 'inline'; document.getElementById('2309.10188v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.10188v1-abstract-full" style="display: none;"> We present model constraints on the atmospheric structure of HD 106906 b, a planetary-mass companion orbiting at a ~700 AU projected separation around a 15 Myr-old stellar binary, using the APOLLO retrieval code on spectral data spanning 1.1-2.5 $渭$m. C/O ratios can provide evidence for companion formation pathways, as such pathways are ambiguous both at wide separations and at star-to-companion mass ratios in the overlap between the distributions of planets and brown dwarfs. We benchmark our code against an existing retrieval of the field L dwarf 2M2224-0158, returning a C/O ratio consistent with previous fits to the same JHKs data, but disagreeing in the thermal structure, cloud properties, and atmospheric scale height. For HD 106906 b, we retrieve C/O $=0.53^{+0.15}_{-0.25}$, consistent with the C/O ratios expected for HD 106906's stellar association and therefore consistent with a stellar-like formation for the companion. We find abundances of H$_2$O and CO near chemical equilibrium values for a solar metallicity, but a surface gravity lower than expected, as well as a thermal profile with sharp transitions in the temperature gradient. Despite high signal-to-noise and spectral resolution, more accurate constraints necessitate data across a broader wavelength range. This work serves as preparation for subsequent retrievals in the era of JWST, as JWST's spectral range provides a promising opportunity to resolve difficulties in fitting low-gravity L dwarfs, and also underscores the need for simultaneous comparative retrievals on L dwarf companions with multiple retrieval codes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.10188v1-abstract-full').style.display = 'none'; document.getElementById('2309.10188v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">39 pages, 21 figures. Accepted for publication in the Astronomical 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/2303.16863">arXiv:2303.16863</a> <span> [<a href="https://arxiv.org/pdf/2303.16863">pdf</a>, <a href="https://arxiv.org/format/2303.16863">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="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/10.1093/mnras/stad753">10.1093/mnras/stad753 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The puzzle of the formation of T8 dwarf Ross 458c </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Gaarn%2C+J">Josefine Gaarn</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">Mark S. Marley</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E+C">Eileen C. Gonzales</a>, <a href="/search/?searchtype=author&query=Calamari%2C+E">Emily Calamari</a>, <a href="/search/?searchtype=author&query=Gagliuffi%2C+D+B">Daniella Bardalez Gagliuffi</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.16863v2-abstract-short" style="display: inline;"> At the lowest masses, the distinction between brown dwarfs and giant exoplanets is often blurred and literature classifications rarely reflect the deuterium burning boundary. Atmospheric characterisation may reveal the extent to which planetary formation pathways contribute to the population of very-low mass brown dwarfs, by revealing if their abundance distributions differ from those of the local… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.16863v2-abstract-full').style.display = 'inline'; document.getElementById('2303.16863v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.16863v2-abstract-full" style="display: none;"> At the lowest masses, the distinction between brown dwarfs and giant exoplanets is often blurred and literature classifications rarely reflect the deuterium burning boundary. Atmospheric characterisation may reveal the extent to which planetary formation pathways contribute to the population of very-low mass brown dwarfs, by revealing if their abundance distributions differ from those of the local field population or, in the case of companions, their primary stars. The T8 dwarf Ross 458c is a possible planetary mass companion to a pair of M dwarfs, and previous work suggests that it is cloudy. We here present the results of the retrieval analysis of Ross 458c, using archival spectroscopic data in the 1.0 to 2.4 micron range. We test a cloud free model as well as a variety of cloudy models and find that the atmosphere of Ross 458c is best described by a cloudy model (strongly preferred). The CH4/H2O is higher than expected at 1.97 +0.13 -0.14. This value is challenging to understand in terms of equilibrium chemistry and plausible C/O ratios. Comparisons to thermochemical grid models suggest a C/O of ~ 1.35, if CH4 and H2O are quenched at 2000 K, requiring vigorous mixing. We find a [C/H] ratio of +0.18, which matches the metallicity of the primary system, suggesting that oxygen is missing from the atmosphere. Even with extreme mixing, the implied C/O is well beyond the typical stellar regime, suggesting a either non-stellar formation pathway, or the sequestration of substantial quantities of oxygen via hitherto unmodeled chemistry or condensation processes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.16863v2-abstract-full').style.display = 'none'; document.getElementById('2303.16863v2-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 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/2212.07399">arXiv:2212.07399</a> <span> [<a href="https://arxiv.org/pdf/2212.07399">pdf</a>, <a href="https://arxiv.org/format/2212.07399">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div 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/acab58">10.3847/1538-4357/acab58 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Patchy Forsterite Clouds in the Atmospheres of Two Highly Variable Exoplanet Analogs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Alejandro%2C+S">Sherelyn Alejandro</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E">Eileen Gonzales</a>, <a href="/search/?searchtype=author&query=Calamari%2C+E">Emily Calamari</a>, <a href="/search/?searchtype=author&query=Gagliuffi%2C+D+B">Daniella Bardalez Gagliuffi</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Tan%2C+X">Xianyu Tan</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</a>, <a href="/search/?searchtype=author&query=Gemma%2C+M+E">Marina E. Gemma</a>, <a href="/search/?searchtype=author&query=Whiteford%2C+N">Niall Whiteford</a>, <a href="/search/?searchtype=author&query=Gaarn%2C+J">Josefine Gaarn</a>, <a href="/search/?searchtype=author&query=Park%2C+G">Grace Park</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="2212.07399v1-abstract-short" style="display: inline;"> We present an atmospheric retrieval analysis of a pair of highly variable, $\sim200~$Myr old, early-T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival $1-15~渭$m spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best describ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.07399v1-abstract-full').style.display = 'inline'; document.getElementById('2212.07399v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.07399v1-abstract-full" style="display: none;"> We present an atmospheric retrieval analysis of a pair of highly variable, $\sim200~$Myr old, early-T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival $1-15~渭$m spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best described by a patchy, high-altitude forsterite (Mg$_2$SiO$_4$) cloud above a deeper, optically thick iron (Fe) cloud. Our model constrains the cloud properties well, including the cloud locations and cloud particle sizes. We find that the patchy forsterite slab cloud inferred from our retrieval may be responsible for the spectral behavior of the observed variability. Our retrieved cloud structure is consistent with the atmospheric structure previously inferred from spectroscopic variability measurements, but clarifies this picture significantly. We find consistent C/O ratios for both objects which supports their formation within the same molecular cloud in the Carina-Near Moving Group. Finally, we note some differences in the constrained abundances of H$_2$O and CO which may be caused by data quality and/or astrophysical processes such as auroral activity and their differing rotation rates. The results presented in this work provide a promising preview of the detail with which we will characterize extrasolar atmospheres with JWST, which will yield higher quality spectra across a wider wavelength range. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.07399v1-abstract-full').style.display = 'none'; document.getElementById('2212.07399v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 December, 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">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/2210.13614">arXiv:2210.13614</a> <span> [<a href="https://arxiv.org/pdf/2210.13614">pdf</a>, <a href="https://arxiv.org/format/2210.13614">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="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/10.3847/1538-4357/ac9cc9">10.3847/1538-4357/ac9cc9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An Atmospheric Retrieval of the Brown Dwarf Gliese 229B </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Calamari%2C+E">Emily Calamari</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E">Eileen Gonzales</a>, <a href="/search/?searchtype=author&query=Bardalez-Gagliuffi%2C+D">Daniella Bardalez-Gagliuffi</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Gemma%2C+M">Marina Gemma</a>, <a href="/search/?searchtype=author&query=Whiteford%2C+N">Niall Whiteford</a>, <a href="/search/?searchtype=author&query=Gaarn%2C+J">Josefine Gaarn</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="2210.13614v1-abstract-short" style="display: inline;"> We present results from an atmospheric retrieval analysis of Gl 229B using the BREWSTER retrieval code. We find the best fit model to be cloud-free, consistent with the T dwarf retrieval work of Line et al. 2017, Zalesky et al. 2022 and Gonzales et al. 2020. Fundamental parameters (mass, radius, log(L_{Bol}/L_{Sun}), log(g)) determined from our model agree within 1蟽to SED-derived values except for… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.13614v1-abstract-full').style.display = 'inline'; document.getElementById('2210.13614v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.13614v1-abstract-full" style="display: none;"> We present results from an atmospheric retrieval analysis of Gl 229B using the BREWSTER retrieval code. We find the best fit model to be cloud-free, consistent with the T dwarf retrieval work of Line et al. 2017, Zalesky et al. 2022 and Gonzales et al. 2020. Fundamental parameters (mass, radius, log(L_{Bol}/L_{Sun}), log(g)) determined from our model agree within 1蟽to SED-derived values except for T_{eff} where our retrieved T_{eff} is approximately 100 K cooler than the evolutionary model-based SED value. We find a retrieved mass of 50^{+12}_{-9} M_{Jup}, however, we also find that the observables of Gl 229B can be explained by a cloud-free model with a prior on mass at the dynamical value, 70 M_{Jup}. We are able to constrain abundances for H_2O, CO, CH_4, NH_3, Na and K and find a supersolar C/O ratio as compared to its primary, Gl 229A. We report an overall subsolar metallicity due to atmospheric oxygen depletion but find a solar [C/H], which matches that of the primary. We find that this work contributes to a growing trend in retrieval-based studies, particularly for brown dwarfs, toward supersolar C/O ratios and discuss the implications of this result on formation mechanisms, internal physical processes as well as model biases. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.13614v1-abstract-full').style.display = 'none'; document.getElementById('2210.13614v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">26 pages, 8 tables, 8 figures. Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.02754">arXiv:2209.02754</a> <span> [<a href="https://arxiv.org/pdf/2209.02754">pdf</a>, <a href="https://arxiv.org/format/2209.02754">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div 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/ac8f2a">10.3847/1538-4357/ac8f2a <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Comparative L-dwarf Sample Exploring the Interplay Between Atmospheric Assumptions and Data Properties </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Gonzales%2C+E+C">Eileen C. Gonzales</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Lewis%2C+N+K">Nikole K. Lewis</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</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="2209.02754v1-abstract-short" style="display: inline;"> Comparisons of atmospheric retrievals can reveal powerful insights on the strengths and limitations of our data and modeling tools. In this paper, we examine a sample of 5 similar effective temperature (Teff) or spectral type L dwarfs to compare their pressure-temperature (P-T) profiles. Additionally, we explore the impact of an object's metallicity and the observations' signal-to-noise (SNR) on t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.02754v1-abstract-full').style.display = 'inline'; document.getElementById('2209.02754v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.02754v1-abstract-full" style="display: none;"> Comparisons of atmospheric retrievals can reveal powerful insights on the strengths and limitations of our data and modeling tools. In this paper, we examine a sample of 5 similar effective temperature (Teff) or spectral type L dwarfs to compare their pressure-temperature (P-T) profiles. Additionally, we explore the impact of an object's metallicity and the observations' signal-to-noise (SNR) on the parameters we can retrieve. We present the first atmospheric retrievals: 2MASS J15261405$+$2043414, 2MASS J05395200$-$0059019, 2MASS J15394189$-$0520428, and GD 165B increasing the small but growing number of L-dwarfs retrieved. When compared to atmospheric retrievals of SDSS J141624.08+134826.7, a low-metallicity d/sdL7 primary in a wide L+T binary, we find similar Teff sources have similar P-T profiles with metallicity differences impacting the relative offset between their P-T profiles in the photosphere. We also find that for near-infrared spectra, when the SNR is $\gtrsim80$ we are in a regime where model uncertainties dominate over data measurement uncertainties. As such, SNR does not play a role in the retrieval's ability to distinguish between a cloud-free and cloudless model, but may impact the confidence of the retrieved parameters. Lastly, we also discuss how to break cloud model degeneracies and the impact of extraneous gases in a retrieval model. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.02754v1-abstract-full').style.display = 'none'; document.getElementById('2209.02754v1-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 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 3 figures, 7 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/2109.11000">arXiv:2109.11000</a> <span> [<a href="https://arxiv.org/pdf/2109.11000">pdf</a>, <a href="https://arxiv.org/format/2109.11000">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="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/10.3847/1538-4357/ac294e">10.3847/1538-4357/ac294e <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The first retrieval of a substellar subdwarf: A cloud-free SDSS J125637.13-022452.4 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Gonzales%2C+E+C">Eileen C. Gonzales</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</a>, <a href="/search/?searchtype=author&query=Lewis%2C+N+K">Nikole K. Lewis</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="2109.11000v1-abstract-short" style="display: inline;"> We present the first retrieval analysis of a substellar subdwarf, SDSS J125637.13-022452.4 (SDSS J1256-0224), using the Brewster retrieval code base. We find SDSS J1256-0224 is best fit by a cloud-free model with an ion (neutral H, H-, and electron) abundance corresponding to ion [Fe/H]=-1.5. However, this model is indistinguishable from a cloud-free model with ion [Fe/H]=-2.0 and a cloud-free mod… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.11000v1-abstract-full').style.display = 'inline'; document.getElementById('2109.11000v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.11000v1-abstract-full" style="display: none;"> We present the first retrieval analysis of a substellar subdwarf, SDSS J125637.13-022452.4 (SDSS J1256-0224), using the Brewster retrieval code base. We find SDSS J1256-0224 is best fit by a cloud-free model with an ion (neutral H, H-, and electron) abundance corresponding to ion [Fe/H]=-1.5. However, this model is indistinguishable from a cloud-free model with ion [Fe/H]=-2.0 and a cloud-free model with ion Fe/H]=-1.5 assuming a subsolar carbon-to-oxygen ratio. We are able to constrain abundances for water, FeH, and CrH, with an inability to constrain any carbon-bearing species likely due to the low-metallicity of SDSS J1256-0224. We also present an updated spectral energy distribution (SED) and semi-empirical fundamental parameters. Our retrieval- and SED-based fundamental parameters agree with the Baraffe low-metallicity evolutionary models. From examining our "rejected" models (those with $螖$BIC>45), we find that we are able to retrieve gas abundances consistent with those of our best-fitting model. We find the cloud in these poorer fitting "cloudy" models is either pushed to the bottom of the atmosphere or made optically thin. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.11000v1-abstract-full').style.display = 'none'; document.getElementById('2109.11000v1-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, 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">19 pages, 5 figures. arXiv admin note: text overlap with arXiv:2010.01224</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.06353">arXiv:2105.06353</a> <span> [<a href="https://arxiv.org/pdf/2105.06353">pdf</a>, <a href="https://arxiv.org/format/2105.06353">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="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/10.3847/1538-4357/abfe14">10.3847/1538-4357/abfe14 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Longitudinally Resolved Spectral Retrieval (ReSpect) of WASP-43b </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cubillos%2C+P+E">Patricio E. Cubillos</a>, <a href="/search/?searchtype=author&query=Keating%2C+D">Dylan Keating</a>, <a href="/search/?searchtype=author&query=Cowan%2C+N+B">Nicolas B. Cowan</a>, <a href="/search/?searchtype=author&query=Vos%2C+J+M">Johanna M. Vos</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Ygouf%2C+M">Marie Ygouf</a>, <a href="/search/?searchtype=author&query=Karalidi%2C+T">Theodora Karalidi</a>, <a href="/search/?searchtype=author&query=Zhou%2C+Y">Yifan Zhou</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E+C">Eileen C. Gonzales</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="2105.06353v1-abstract-short" style="display: inline;"> Thermal phase variations of short period planets indicate that they are not spherical cows: day-to-night temperature contrasts range from hundreds to thousands of degrees, rivaling their vertical temperature contrasts. Nonetheless, the emergent spectra of short-period planets have typically been fit using one-dimensional (1D) spectral retrieval codes that only account for vertical temperature grad… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.06353v1-abstract-full').style.display = 'inline'; document.getElementById('2105.06353v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.06353v1-abstract-full" style="display: none;"> Thermal phase variations of short period planets indicate that they are not spherical cows: day-to-night temperature contrasts range from hundreds to thousands of degrees, rivaling their vertical temperature contrasts. Nonetheless, the emergent spectra of short-period planets have typically been fit using one-dimensional (1D) spectral retrieval codes that only account for vertical temperature gradients. The popularity of 1D spectral retrieval codes is easy to understand: they are robust and have a rich legacy in Solar System atmospheric studies. Exoplanet researchers have recently introduced multi-dimensional retrieval schemes for interpreting the spectra of short-period planets, but these codes are necessarily more complex and computationally expensive than their 1D counterparts. In this paper we present an alternative: phase-dependent spectral observations are inverted to produce longitudinally resolved spectra that can then be fitted using standard 1D spectral retrieval codes. We test this scheme on the iconic phase-resolved spectra of WASP-43b and on simulated JWST observations using the open-source pyratbay 1D spectral retrieval framework. Notably, we take the model complexity of the simulations one step further over previous studies by allowing for longitudinal variations in composition in addition to temperature. We show that performing 1D spectral retrieval on longitudinally resolved spectra is more accurate than applying 1D spectral retrieval codes to disk-integrated emission spectra, despite being identical in terms of computational load. We find that for the extant Hubble and Spitzer observations of WASP-43b the difference between the two approaches is negligible but that JWST phase measurements should be treated with longitudinally \textbf{re}solved \textbf{spect}ral retrieval (ReSpect). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.06353v1-abstract-full').style.display = 'none'; document.getElementById('2105.06353v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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 at 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/2105.04268">arXiv:2105.04268</a> <span> [<a href="https://arxiv.org/pdf/2105.04268">pdf</a>, <a href="https://arxiv.org/format/2105.04268">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="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/10.1093/mnras/stab1361">10.1093/mnras/stab1361 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Cloud busting: enstatite and quartz clouds in the atmosphere of 2M2224-0158 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Gonzales%2C+E+C">Eileen C. Gonzales</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">Mark S. Marley</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Gaarn%2C+J">Josefine Gaarn</a>, <a href="/search/?searchtype=author&query=Bieger%2C+M+F">Michelle Fabienne Bieger</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</a>, <a href="/search/?searchtype=author&query=Saumon%2C+D">Didier Saumon</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="2105.04268v1-abstract-short" style="display: inline;"> We present the most detailed data-driven exploration of cloud opacity in a substellar object to-date. We have tested over 60 combinations of cloud composition and structure, particle size distribution, scattering model, and gas phase composition assumptions against archival $1-15 {\rm 渭m}$ spectroscopy for the unusually red L4.5~dwarf 2MASSW~J2224438-015852 using the Brewster retrieval framework.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.04268v1-abstract-full').style.display = 'inline'; document.getElementById('2105.04268v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.04268v1-abstract-full" style="display: none;"> We present the most detailed data-driven exploration of cloud opacity in a substellar object to-date. We have tested over 60 combinations of cloud composition and structure, particle size distribution, scattering model, and gas phase composition assumptions against archival $1-15 {\rm 渭m}$ spectroscopy for the unusually red L4.5~dwarf 2MASSW~J2224438-015852 using the Brewster retrieval framework. We find that, within our framework, a model that includes enstatite and quartz cloud layers at shallow pressures, combined with a deep iron cloud deck fits the data best. This models assumes a Hansen distribution for particle sizes for each cloud, and Mie scattering. We retrieved particle effective radii of $\log_{10} a {\rm (渭m)} = -1.41^{+0.18}_{-0.17}$ for enstatite, $-0.44^{+0.04}_{-0.20}$ for quartz, and $-0.77^{+0.05}_{-0.06}$ for iron. Our inferred cloud column densities suggest ${\rm (Mg/Si)} = 0.69^{+0.06}_{-0.08}$ if there are no other sinks for magnesium or silicon. Models that include forsterite alongside, or in place of, these cloud species are strongly rejected in favour of the above combination. We estimate a radius of $0.75 \pm 0.02$ Rjup, which is considerably smaller than predicted by evolutionary models for a field age object with the luminosity of 2M2224-0158. Models which assume vertically constant gas fractions are consistently preferred over models that assume thermochemical equilibrium. From our retrieved gas fractions we infer ${\rm [M/H]} = +0.38^{+0.07}_{-0.06}$ and ${\rm C/O} = 0.83^{+0.06}_{-0.07}$. Both these values are towards the upper end of the stellar distribution in the Solar neighbourhood, and are mutually consistent in this context. A composition toward the extremes of the local distribution is consistent with this target being an outlier in the ultracool dwarf population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.04268v1-abstract-full').style.display = 'none'; document.getElementById('2105.04268v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">20 pages, 10 figures, MNRAS accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.05731">arXiv:2012.05731</a> <span> [<a href="https://arxiv.org/pdf/2012.05731">pdf</a>, <a href="https://arxiv.org/format/2012.05731">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="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/10.1093/mnras/staa3836">10.1093/mnras/staa3836 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Serendipitous discovery of a dusty disc around WDJ181417.84-735459.83 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Egea%2C+E+G">E. Gonz谩lez Egea</a>, <a href="/search/?searchtype=author&query=Raddi%2C+R">R. Raddi</a>, <a href="/search/?searchtype=author&query=Koester%2C+D">D. Koester</a>, <a href="/search/?searchtype=author&query=Rogers%2C+L+K">L. K. Rogers</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Cooper%2C+W+J">W. J. Cooper</a>, <a href="/search/?searchtype=author&query=Beamin%2C+J+C">J. C. Beamin</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A">A. Day-Jones</a>, <a href="/search/?searchtype=author&query=Forbrich%2C+J">J. Forbrich</a>, <a href="/search/?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="2012.05731v2-abstract-short" style="display: inline;"> Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the DA white dwarf WDJ181417.84$-$735459.83, an object originally identified to have a strong infrared excess in the 2MASS and WISE catalogues that we confirmed to be intrinsic to th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.05731v2-abstract-full').style.display = 'inline'; document.getElementById('2012.05731v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.05731v2-abstract-full" style="display: none;"> Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the DA white dwarf WDJ181417.84$-$735459.83, an object originally identified to have a strong infrared excess in the 2MASS and WISE catalogues that we confirmed to be intrinsic to the white dwarf, and likely corresponding to the emission of a dusty disc around the star. The finding of Ca, Fe and Mg absorption lines in two X-SHOOTER spectra of the white dwarf, taken 8 years apart, is further evidence of accretion from a dusty disc. We do not report variability in the absorption lines between these two spectra. Fitting a blackbody model to the infrared excess gives a temperature of 910$\pm50$ K. We have estimated a total accretion flux from the spectroscopic metal lines of $|\dot{\rm M}| = 1.784 \times 10^{9}\, $g s$^{-1}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.05731v2-abstract-full').style.display = 'none'; document.getElementById('2012.05731v2-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, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 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">Accepted for publication in MNRAS. 11 pages, 10 figures, 6 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/2010.01224">arXiv:2010.01224</a> <span> [<a href="https://arxiv.org/pdf/2010.01224">pdf</a>, <a href="https://arxiv.org/format/2010.01224">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="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/10.3847/1538-4357/abbee2">10.3847/1538-4357/abbee2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Retrieval of SDSS J1416+1348AB </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Gonzales%2C+E">Eileen Gonzales</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J">Jackie Faherty</a>, <a href="/search/?searchtype=author&query=Cleary%2C+C">Colleen Cleary</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</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="2010.01224v1-abstract-short" style="display: inline;"> We present the distance-calibrated spectral energy distribution (SED) of the d/sdL7 SDSS J14162408+1348263A (J1416A) and an updated SED for SDSS J14162408+1348263B (J1416B). We also present the first retrieval analysis of J1416A using the Brewster retrieval code base and the second retrieval of J1416B. We find that the primary is best fit by a non-grey cloud opacity with a power-law wavelength dep… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.01224v1-abstract-full').style.display = 'inline'; document.getElementById('2010.01224v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.01224v1-abstract-full" style="display: none;"> We present the distance-calibrated spectral energy distribution (SED) of the d/sdL7 SDSS J14162408+1348263A (J1416A) and an updated SED for SDSS J14162408+1348263B (J1416B). We also present the first retrieval analysis of J1416A using the Brewster retrieval code base and the second retrieval of J1416B. We find that the primary is best fit by a non-grey cloud opacity with a power-law wavelength dependence, but is indistinguishable between the type of cloud parameterization. J1416B is best fit by a cloud-free model, consistent with the results from Line et al. (2017). Most fundamental parameters derived via SEDs and retrievals are consistent within 1 sigma for both J1416A and J1416B. The exceptions include the radius of J1416A, where the retrieved radius is smaller than the evolutionary model-based radius from the SED for the deck cloud model, and the bolometric luminosity which is consistent within 2.5 sigma for both cloud models. The pair's metallicity and Carbon-to-Oxygen (C/O) ratio point towards formation and evolution as a system. By comparing the retrieved alkali abundances while using two opacity models, we are able to evaluate how the opacities behave for the L and T dwarf. Lastly, we find that relatively small changes in composition can drive major observable differences for lower temperature objects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.01224v1-abstract-full').style.display = 'none'; document.getElementById('2010.01224v1-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 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">40 pages, 25 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/2001.11015">arXiv:2001.11015</a> <span> [<a href="https://arxiv.org/pdf/2001.11015">pdf</a>, <a href="https://arxiv.org/format/2001.11015">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="Earth and Planetary Astrophysics">astro-ph.EP</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/staa3118">10.1093/mnras/staa3118 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Increasing the census of L and T dwarfs in wide binary and multiple systems using Dark Energy Survey DR1 and Gaia DR2 data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Ponte%2C+M+d">M. dal Ponte</a>, <a href="/search/?searchtype=author&query=Santiago%2C+B">B. Santiago</a>, <a href="/search/?searchtype=author&query=Rosell%2C+A+C">A. Carnero Rosell</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Yanny%2C+B">B. Yanny</a>, <a href="/search/?searchtype=author&query=Marshall%2C+J+L">J. L. Marshall</a>, <a href="/search/?searchtype=author&query=Bechtol%2C+K">K. Bechtol</a>, <a href="/search/?searchtype=author&query=Martini%2C+P">P. Martini</a>, <a href="/search/?searchtype=author&query=Li%2C+T+S">T. S. Li</a>, <a href="/search/?searchtype=author&query=De+Paris%2C+L">L. De Paris</a>, <a href="/search/?searchtype=author&query=Abbott%2C+T+M+C">T. M. C. Abbott</a>, <a href="/search/?searchtype=author&query=Aguena%2C+M">M. Aguena</a>, <a href="/search/?searchtype=author&query=Allam%2C+S">S. Allam</a>, <a href="/search/?searchtype=author&query=Avila%2C+S">S. Avila</a>, <a href="/search/?searchtype=author&query=Bertin%2C+E">E. Bertin</a>, <a href="/search/?searchtype=author&query=Bhargava%2C+S">S. Bhargava</a>, <a href="/search/?searchtype=author&query=Brooks%2C+D">D. Brooks</a>, <a href="/search/?searchtype=author&query=Buckley-Geer%2C+E">E. Buckley-Geer</a>, <a href="/search/?searchtype=author&query=Kind%2C+M+C">M. Carrasco Kind</a>, <a href="/search/?searchtype=author&query=Carretero%2C+J">J. Carretero</a>, <a href="/search/?searchtype=author&query=da+Costa%2C+L+N">L. N. da Costa</a>, <a href="/search/?searchtype=author&query=De+Vicente%2C+J">J. De Vicente</a>, <a href="/search/?searchtype=author&query=Diehl%2C+H+T">H. T. Diehl</a>, <a href="/search/?searchtype=author&query=Doel%2C+P">P. Doel</a>, <a href="/search/?searchtype=author&query=Eifler%2C+T+F">T. F. Eifler</a> , et al. (35 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="2001.11015v2-abstract-short" style="display: inline;"> We present the discovery of 255 binary and six multiple system candidates with wide > 5" separation composed by ultracool dwarfs companions to stars, plus nine double ultracool dwarf systems. These systems were selected based on common distance criteria. About 90% of the total sample has proper motions available and 73% of the systems also satisfy a common proper motion criterion. The sample of ul… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.11015v2-abstract-full').style.display = 'inline'; document.getElementById('2001.11015v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.11015v2-abstract-full" style="display: none;"> We present the discovery of 255 binary and six multiple system candidates with wide > 5" separation composed by ultracool dwarfs companions to stars, plus nine double ultracool dwarf systems. These systems were selected based on common distance criteria. About 90% of the total sample has proper motions available and 73% of the systems also satisfy a common proper motion criterion. The sample of ultracool candidates was taken from the Dark Energy Survey (DES) and the candidate stellar primaries are from Gaia DR2 and DES data. We compute chance alignment probabilities in order to assess the physical nature of each pair. We find that 174 candidate pairs with Gaia DR2 primaries and 81 pairs with a DES star as a primary have chance alignment probabilities < 5%. Only nine candidate systems composed of two ultracool dwarfs were identified. The sample of candidate multiple systems is made up of five triple systems and one quadruple system. The majority of the ultracool dwarfs found in binaries and multiples are of early L type and the typical wide binary fraction over the L spectral types is 2-4%. Our sample of candidate wide binaries with ultracool dwarfs as secondaries constitutes a substantial increase over the known number of such systems, which are very useful to constrain the formation and evolution of ultracool dwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.11015v2-abstract-full').style.display = 'none'; document.getElementById('2001.11015v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">18 pages, 10 figures. Accepted by MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1903.10806">arXiv:1903.10806</a> <span> [<a href="https://arxiv.org/pdf/1903.10806">pdf</a>, <a href="https://arxiv.org/format/1903.10806">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/stz2398">10.1093/mnras/stz2398 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Brown dwarf census with the Dark Energy Survey year 3 data and the thin disk scale height of early L types </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Rosell%2C+A+C">A. Carnero Rosell</a>, <a href="/search/?searchtype=author&query=Santiago%2C+B">B. Santiago</a>, <a href="/search/?searchtype=author&query=Ponte%2C+M+d">M. dal Ponte</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=da+Costa%2C+L+N">L. N. da Costa</a>, <a href="/search/?searchtype=author&query=James%2C+D+J">D. J. James</a>, <a href="/search/?searchtype=author&query=Marshall%2C+J+L">J. L. Marshall</a>, <a href="/search/?searchtype=author&query=McMahon%2C+R+G">R. G. McMahon</a>, <a href="/search/?searchtype=author&query=Bechtol%2C+K">K. Bechtol</a>, <a href="/search/?searchtype=author&query=De+Paris%2C+L">L. De Paris</a>, <a href="/search/?searchtype=author&query=Li%2C+T">T. Li</a>, <a href="/search/?searchtype=author&query=Pieres%2C+A">A. Pieres</a>, <a href="/search/?searchtype=author&query=Abbott%2C+T+M+C">T. M. C. Abbott</a>, <a href="/search/?searchtype=author&query=Annis%2C+J">J. Annis</a>, <a href="/search/?searchtype=author&query=Avila%2C+S">S. Avila</a>, <a href="/search/?searchtype=author&query=Bernstein%2C+G+M">G. M. Bernstein</a>, <a href="/search/?searchtype=author&query=Brooks%2C+D">D. Brooks</a>, <a href="/search/?searchtype=author&query=Burke%2C+D+L">D. L. Burke</a>, <a href="/search/?searchtype=author&query=Carrasco-Kind%2C+M">M. Carrasco-Kind</a>, <a href="/search/?searchtype=author&query=Carretero%2C+J">J. Carretero</a>, <a href="/search/?searchtype=author&query=De+Vicente%2C+J">J. De Vicente</a>, <a href="/search/?searchtype=author&query=Drlica-Wagner%2C+A">A. Drlica-Wagner</a>, <a href="/search/?searchtype=author&query=Fosalba%2C+P">P. Fosalba</a>, <a href="/search/?searchtype=author&query=Frieman%2C+J">J. Frieman</a>, <a href="/search/?searchtype=author&query=Garcia-Bellido%2C+J">J. Garcia-Bellido</a> , et al. (22 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="1903.10806v1-abstract-short" style="display: inline;"> In this paper we present a catalogue of 11,745 brown dwarfs with spectral types ranging from L0 to T9, photometrically classified using data from the Dark Energy Survey (DES) year 3 release matched to the Vista Hemisphere Survey (VHS) DR3 and Wide-field Infrared Survey Explorer (WISE) data, covering approx 2,400 deg2 up to i_AB=22. The classification method follows the same photo-type method previ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.10806v1-abstract-full').style.display = 'inline'; document.getElementById('1903.10806v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.10806v1-abstract-full" style="display: none;"> In this paper we present a catalogue of 11,745 brown dwarfs with spectral types ranging from L0 to T9, photometrically classified using data from the Dark Energy Survey (DES) year 3 release matched to the Vista Hemisphere Survey (VHS) DR3 and Wide-field Infrared Survey Explorer (WISE) data, covering approx 2,400 deg2 up to i_AB=22. The classification method follows the same photo-type method previously applied to SDSS-UKIDSS-WISE data. The most significant difference comes from the use of DES data instead of SDSS, which allow us to classify almost an order of magnitude more brown dwarfs than any previous search and reaching distances beyond 400 parsecs for the earliest types. Next, we also present and validate the GalmodBD simulation, which produces brown dwarf number counts as a function of structural parameters with realistic photometric properties of a given survey. We use this simulation to estimate the completeness and purity of our photometric LT catalogue down to i_AB=22, as well as to compare to the observed number of LT types. We put constraints on the thin disk scale height for the early L population to be around 450 parsecs, in agreement with previous findings. For completeness, we also publish in a separate table a catalogue of 20,863 M dwarfs that passed our colour cut with spectral types greater than M6. Both the LT and the late M catalogues are found at https://des.ncsa.illinois.edu/releases/other/y3-mlt <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.10806v1-abstract-full').style.display = 'none'; document.getElementById('1903.10806v1-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, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">27 pages, 18 figures. Submitted to MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1811.00672">arXiv:1811.00672</a> <span> [<a href="https://arxiv.org/pdf/1811.00672">pdf</a>, <a href="https://arxiv.org/ps/1811.00672">ps</a>, <a href="https://arxiv.org/format/1811.00672">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/sty2520">10.1093/mnras/sty2520 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Parallaxes of southern extremely cool objects III: 118 L \& T dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Bucciarelli%2C+B">B. Bucciarelli</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Andrei%2C+A+H">A. H. Andrei</a>, <a href="/search/?searchtype=author&query=Goldman%2C+B">B. Goldman</a>, <a href="/search/?searchtype=author&query=Mendez%2C+R+A">R. A. Mendez</a>, <a href="/search/?searchtype=author&query=d%27Avila%2C+V+A">V. A. d'Avila</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Camargo%2C+J+I+B">J. I. B. Camargo</a>, <a href="/search/?searchtype=author&query=Crosta%2C+M+T">M. T. Crosta</a>, <a href="/search/?searchtype=author&query=Dapr%C3%A0%2C+M">M. Dapr脿</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+S">J. S. Jenkins</a>, <a href="/search/?searchtype=author&query=Lachaume%2C+R">R. Lachaume</a>, <a href="/search/?searchtype=author&query=Lattanzi%2C+M+G">M. G. Lattanzi</a>, <a href="/search/?searchtype=author&query=Penna%2C+J+L">J. L. Penna</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Neto%2C+D+N+d+S">D. N. da Silva Neto</a>, <a href="/search/?searchtype=author&query=Sozzetti%2C+A">A. Sozzetti</a>, <a href="/search/?searchtype=author&query=Vecchiato%2C+A">A. Vecchiato</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="1811.00672v1-abstract-short" style="display: inline;"> We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multi-epoch photometry of L and early T dwarfs. The observations were made on 108 nights over the course of 8 years using the Wide Field Imager on the ESO 2.2m telescope. We present 118 new parallaxes of L \& T dwarfs of which 52 have no published values and 24 of the 66 p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.00672v1-abstract-full').style.display = 'inline'; document.getElementById('1811.00672v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1811.00672v1-abstract-full" style="display: none;"> We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multi-epoch photometry of L and early T dwarfs. The observations were made on 108 nights over the course of 8 years using the Wide Field Imager on the ESO 2.2m telescope. We present 118 new parallaxes of L \& T dwarfs of which 52 have no published values and 24 of the 66 published values are preliminary estimates from this program. The parallax precision varies from 1.0 to 15.5 mas with a median of 3.8 mas. We find evidence for 2 objects with long term photometric variation and 24 new moving group candidates. We cross-match our sample to published photometric catalogues and find standard magnitudes in up to 16 pass-bands from which we build spectral energy distributions and H-R diagrams. This allows us to confirm the theoretically anticipated minimum in radius between stars and brown dwarfs across the hydrogen burning minimum mass. We find the minimum occurs between L2 and L6 and verify the predicted steep dependence of radius in the hydrogen burning regime and the gentle rise into the degenerate brown dwarf regime. We find a relatively young age of 2 Gyr from the kinematics of our sample. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1811.00672v1-abstract-full').style.display = 'none'; document.getElementById('1811.00672v1-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 November, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2018. </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">In press MNRAS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 2018MNRAS.481.3548S </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1807.10560">arXiv:1807.10560</a> <span> [<a href="https://arxiv.org/pdf/1807.10560">pdf</a>, <a href="https://arxiv.org/format/1807.10560">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/sty2054">10.1093/mnras/sty2054 <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 - IV. New L subdwarfs, Gaia astrometry, population properties, and a blue brown dwarf binary </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/?searchtype=author&query=Galvez-Ortiz%2C+M+C">M. C. Galvez-Ortiz</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Martin%2C+E+L">E. L. Martin</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Homeier%2C+D">D. Homeier</a>, <a href="/search/?searchtype=author&query=Allard%2C+F">F. Allard</a>, <a href="/search/?searchtype=author&query=Osorio%2C+M+R+Z">M. R. Zapatero Osorio</a>, <a href="/search/?searchtype=author&query=Smith%2C+L+C">L. C. Smith</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Marti%2C+B+L">B. Lopez Marti</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Rebolo%2C+R">R. Rebolo</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="1807.10560v4-abstract-short" style="display: inline;"> We present 27 new L subdwarfs and classify five of them as esdL and 22 as sdL. Our L subdwarf candidates were selected with the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Spectroscopic follow-up was carried out primarily with the OSIRIS spectrograph on the Gran Telescopio Canarias. Some of these new objects were followed up with the X-shooter instrument on the Very Large Telescop… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.10560v4-abstract-full').style.display = 'inline'; document.getElementById('1807.10560v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1807.10560v4-abstract-full" style="display: none;"> We present 27 new L subdwarfs and classify five of them as esdL and 22 as sdL. Our L subdwarf candidates were selected with the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Spectroscopic follow-up was carried out primarily with the OSIRIS spectrograph on the Gran Telescopio Canarias. Some of these new objects were followed up with the X-shooter instrument on the Very Large Telescope. We studied the photometric properties of the population of known L subdwarfs using colour-spectral type diagrams and colour-colour diagrams, by comparison with L dwarfs and main-sequence stars, and identified new colour spaces for L subdwarf selection/study in current and future surveys. We further discussed the brown dwarf transition-zone and the observational stellar/substellar boundary. We found that about one-third of 66 known L subdwarfs are substellar objects, with two-thirds being very low-mass stars. We also present the Hertzsprung-Russell diagrams, spectral type-absolute magnitude corrections, and tangential velocities of 20 known L subdwarfs observed by the Gaia astrometry satellite. One of our L subdwarf candidates, ULAS J233227.03+123452.0, is a mildly metal-poor spectroscopic binary brown dwarf: a ~L6p dwarf and a ~T4p dwarf. This binary is likely a thick disc member according to its kinematics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.10560v4-abstract-full').style.display = 'none'; document.getElementById('1807.10560v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 July, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2018. </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">30 pages, 23 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/1805.08033">arXiv:1805.08033</a> <span> [<a href="https://arxiv.org/pdf/1805.08033">pdf</a>, <a href="https://arxiv.org/format/1805.08033">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/sty1352">10.1093/mnras/sty1352 <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 - III. The halo transitional brown dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Galvez-Ortiz%2C+M+C">M. C. Galvez-Ortiz</a>, <a href="/search/?searchtype=author&query=Homeier%2C+D">D. Homeier</a>, <a href="/search/?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/?searchtype=author&query=Martin%2C+E+L">E. L. Martin</a>, <a href="/search/?searchtype=author&query=Osorio%2C+M+R+Z">M. R. Zapatero Osorio</a>, <a href="/search/?searchtype=author&query=Allard%2C+F">F. Allard</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Marti%2C+B+L">B. Lopez Marti</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Rebolo%2C+R">R. Rebolo</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="1805.08033v2-abstract-short" style="display: inline;"> We report the discovery of an esdL3 subdwarf, ULAS J020858.62+020657.0, and a usdL4.5 subdwarf, ULAS J230711.01+014447.1. They were identified as L subdwarfs by optical spectra obtained with the Gran Telescopio Canarias, and followed up by optical-to-near-infrared spectroscopy with the Very Large Telescope. We also obtained an optical-to-near-infrared spectrum of a previously known L subdwarf, ULA… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.08033v2-abstract-full').style.display = 'inline'; document.getElementById('1805.08033v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.08033v2-abstract-full" style="display: none;"> We report the discovery of an esdL3 subdwarf, ULAS J020858.62+020657.0, and a usdL4.5 subdwarf, ULAS J230711.01+014447.1. They were identified as L subdwarfs by optical spectra obtained with the Gran Telescopio Canarias, and followed up by optical-to-near-infrared spectroscopy with the Very Large Telescope. We also obtained an optical-to-near-infrared spectrum of a previously known L subdwarf, ULAS J135058.85+081506.8, and reclassified it as a usdL3 subdwarf. These three objects all have typical halo kinematics. They have $T_{\rm eff}$ around 2050$-$2250 K, $-$1.8 $\leq$ [Fe/H] $\leq -$1.5, and mass around 0.0822$-$0.0833 M$_{\odot}$, according to model spectral fitting and evolutionary models. These sources are likely halo transitional brown dwarfs with unsteady hydrogen fusion, as their masses are just below the hydrogen-burning minimum mass, which is $\sim$ 0.0845 M$_{\odot}$ at [Fe/H] = $-$1.6 and $\sim$ 0.0855 M$_{\odot}$ at [Fe/H] = $-$1.8. Including these, there are now nine objects in the `halo brown dwarf transition zone', which is a `substellar subdwarf gap' that spans a wide temperature range within a narrow mass range of the substellar population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.08033v2-abstract-full').style.display = 'none'; document.getElementById('1805.08033v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </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, 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/1805.05661">arXiv:1805.05661</a> <span> [<a href="https://arxiv.org/pdf/1805.05661">pdf</a>, <a href="https://arxiv.org/format/1805.05661">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/978-3-319-55333-7_118">10.1007/978-3-319-55333-7_118 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Large Scale Searches for Brown Dwarfs and Free-Floating Planets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</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="1805.05661v1-abstract-short" style="display: inline;"> Searches of large scale surveys have resulted in the discovery of over 1000 brown dwarfs in the Solar neighbourhood. In this chapter we review the progress in finding brown dwarfs in large datasets, highlighting the key science goals, and summarising the surveys that have contributed most significantly to the current sample. </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.05661v1-abstract-full" style="display: none;"> Searches of large scale surveys have resulted in the discovery of over 1000 brown dwarfs in the Solar neighbourhood. In this chapter we review the progress in finding brown dwarfs in large datasets, highlighting the key science goals, and summarising the surveys that have contributed most significantly to the current sample. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.05661v1-abstract-full').style.display = 'none'; document.getElementById('1805.05661v1-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 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </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 to appear in the Handbook of Exoplanets (Springer); Editors: Hans J. Deeg & Juan Antonio Belmonte</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1704.03136">arXiv:1704.03136</a> <span> [<a href="https://arxiv.org/pdf/1704.03136">pdf</a>, <a href="https://arxiv.org/format/1704.03136">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/10.3847/1538-3881/aa615f">10.3847/1538-3881/aa615f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Kepler-1649b: An Exo-Venus in the Solar Neighborhood </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Angelo%2C+I">Isabel Angelo</a>, <a href="/search/?searchtype=author&query=Rowe%2C+J+F">Jason F. Rowe</a>, <a href="/search/?searchtype=author&query=Howell%2C+S+B">Steve B. Howell</a>, <a href="/search/?searchtype=author&query=Quintana%2C+E+V">Elisa V. Quintana</a>, <a href="/search/?searchtype=author&query=Still%2C+M">Martin Still</a>, <a href="/search/?searchtype=author&query=Mann%2C+A+W">Andrew W. Mann</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Barclay%2C+T">Thomas Barclay</a>, <a href="/search/?searchtype=author&query=Ciardi%2C+D+R">David R. Ciardi</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Kane%2C+S">Stephen Kane</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="1704.03136v1-abstract-short" style="display: inline;"> The Kepler mission has revealed that Earth-sized planets are common, and dozens have been discovered to orbit in or near their host star's habitable zone. A major focus in astronomy is to determine which of these exoplanets are likely to have Earth-like properties that are amenable to follow-up with both ground- and future space-based surveys, with an ultimate goal of probing their atmospheres to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.03136v1-abstract-full').style.display = 'inline'; document.getElementById('1704.03136v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1704.03136v1-abstract-full" style="display: none;"> The Kepler mission has revealed that Earth-sized planets are common, and dozens have been discovered to orbit in or near their host star's habitable zone. A major focus in astronomy is to determine which of these exoplanets are likely to have Earth-like properties that are amenable to follow-up with both ground- and future space-based surveys, with an ultimate goal of probing their atmospheres to look for signs of life. Venus-like atmospheres will be of particular interest in these surveys. While Earth and Venus evolved to have similar sizes and densities, it remains unclear what factors led to the dramatic divergence of their atmospheres. Studying analogs to both Earth and Venus can thus shed light on the limits of habitability and the potential for life on known exoplanets. Here we present the discovery and confirmation of Kepler-1649b, an Earth-sized planet orbiting a nearby M5V star that receives incident flux at a level similar to that of Venus. We present our methods for characterizing the star, using a combination of PSF photometry, ground-based spectroscopy and imaging, to confirm the planetary nature of Kepler-1649b. Planets like Kepler-1649b will be prime candidates for atmospheric and habitability studies in the next generation of space missions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.03136v1-abstract-full').style.display = 'none'; document.getElementById('1704.03136v1-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, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2017. </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, 9 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astronomical Journal (2017), Volume 153, Number 4 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.01245">arXiv:1703.01245</a> <span> [<a href="https://arxiv.org/pdf/1703.01245">pdf</a>, <a href="https://arxiv.org/format/1703.01245">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stw3376">10.1093/mnras/stw3376 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Robust detection of quasi-periodic variability: A HAWKI mini survey of late T dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Littlefair%2C+S+P">S. P. Littlefair</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Helling%2C+C">Ch. Helling</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="1703.01245v1-abstract-short" style="display: inline;"> We present HAWK-I J-band light curves of five late-type T dwarfs (T6.5-T7.5) with a typical duration of four hours, and investigate the evidence for quasi-periodic photometric variability on intra-night timescales. Our photometry reaches precisions in the range 7-20 mmag, after removing instrumental systematics that correlate with sky background, seeing and airmass. Based upon a Lomb-Scargle perio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.01245v1-abstract-full').style.display = 'inline'; document.getElementById('1703.01245v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.01245v1-abstract-full" style="display: none;"> We present HAWK-I J-band light curves of five late-type T dwarfs (T6.5-T7.5) with a typical duration of four hours, and investigate the evidence for quasi-periodic photometric variability on intra-night timescales. Our photometry reaches precisions in the range 7-20 mmag, after removing instrumental systematics that correlate with sky background, seeing and airmass. Based upon a Lomb-Scargle periodogram analysis, the latest object in the sample - ULAS J2321 (T7.5) - appears to show quasi-periodic variability with a period of 1.64 hours and an amplitude of 3 mmag. Given the low amplitude of variability and presence of systematics in our lightcurves, we discuss a Bayesian approach to robustly determine if quasi-periodic variability is present in a lightcurve affected by red noise. Using this approach, we conclude that the evidence for quasi-periodic variability in ULAS J2321 is not significant. As a result, we suggest that studies which identify quasi-periodic variables using the false alarm probability from a Lomb-Scargle periodogram are likely to over-estimate the number of variable objects, even if field stars are used to set a higher false alarm probability threshold. Instead we argue that a hybrid approach combining a false alarm probability cut, followed by Bayesian model selection, is necessary for robust identification of quasi-periodic variability in lightcurves with red noise. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.01245v1-abstract-full').style.display = 'none'; document.getElementById('1703.01245v1-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 March, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </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, accepted for publication in Monthly Notices of the Royal Astronomical Society</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.00463">arXiv:1703.00463</a> <span> [<a href="https://arxiv.org/pdf/1703.00463">pdf</a>, <a href="https://arxiv.org/format/1703.00463">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stx303">10.1093/mnras/stx303 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Low-resolution near-infrared spectroscopic signatures of unresolved ultracool companions to M dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cook%2C+N+J">N. J. Cook</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Frith%2C+J">J. Frith</a>, <a href="/search/?searchtype=author&query=Zhong%2C+J">J. Zhong</a>, <a href="/search/?searchtype=author&query=Luo%2C+A+L">A. L. Luo</a>, <a href="/search/?searchtype=author&query=Qi%2C+Z+X">Z. X. Qi</a>, <a href="/search/?searchtype=author&query=Cowan%2C+N+B">N. B. Cowan</a>, <a href="/search/?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/?searchtype=author&query=Kurtev%2C+R+G">R. G. Kurtev</a>, <a href="/search/?searchtype=author&query=Guo%2C+Y+X">Y. X. Guo</a>, <a href="/search/?searchtype=author&query=Wang%2C+Y+F">Y. F. Wang</a>, <a href="/search/?searchtype=author&query=Song%2C+Y+H">Y. H. Song</a>, <a href="/search/?searchtype=author&query=Yi%2C+Z+P">Z. P. Yi</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</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="1703.00463v1-abstract-short" style="display: inline;"> We develop a method to identify the spectroscopic signature of unresolved L-dwarf ultracool companions, which compares the spectra of candidates and their associated control stars using spectral ratio differences and residual spectra. We present SpeX prism-mode spectra (0.7-2.5 micron) for a pilot sample of 111 mid M dwarfs, including 28 that were previously identified as candidates for unresolved… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.00463v1-abstract-full').style.display = 'inline'; document.getElementById('1703.00463v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.00463v1-abstract-full" style="display: none;"> We develop a method to identify the spectroscopic signature of unresolved L-dwarf ultracool companions, which compares the spectra of candidates and their associated control stars using spectral ratio differences and residual spectra. We present SpeX prism-mode spectra (0.7-2.5 micron) for a pilot sample of 111 mid M dwarfs, including 28 that were previously identified as candidates for unresolved ultracool companionship (a sub-sample from Cook et al. 2016; paper 1) and 83 single M dwarfs that were optically colour-similar to these candidates (which we use as `control stars'). We identify four candidates with evidence for near-infrared excess. One of these (WISE J100202.50+074136.3) shows strong evidence for an unresolved L dwarf companion in both its spectral ratio difference and its residual spectra, two most likely have a different source for the near-infrared excess, and the other may be due to spectral noise. We also establish expectations for a null result (i.e. by searching for companionship signatures around the M dwarf control stars), as well as determining the expected outcome for ubiquitous companionship (as a means of comparison with our actual results), using artificially generated unresolved M+L dwarf spectra. The results of these analyses are compared to those for the candidate sample, and reasonable consistency is found. With a full follow-up programme of our candidates sample from Cook et al., we might expect to confirm up to 40 such companions in the future, adding extensively to the known desert population of M3-M5 dwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.00463v1-abstract-full').style.display = 'none'; document.getElementById('1703.00463v1-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 March, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </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 MNRAS 2017-02-01. Main article 15 pages, 9 figures, 4 tables; plus additional 5 pages of appendices</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1701.01257">arXiv:1701.01257</a> <span> [<a href="https://arxiv.org/pdf/1701.01257">pdf</a>, <a href="https://arxiv.org/format/1701.01257">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="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/10.1093/mnras/stx1246">10.1093/mnras/stx1246 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Retrieval of atmospheric properties of cloudy L dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">Mark S. Marley</a>, <a href="/search/?searchtype=author&query=Line%2C+M+R">Michael R. Line</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Visscher%2C+C">Channon Visscher</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Saumon%2C+D">Didier Saumon</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</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="1701.01257v2-abstract-short" style="display: inline;"> We present the first results from applying the spectral inversion technique in the cloudy L dwarf regime. Our new framework provides a flexible approach to modelling cloud opacity which can be built incrementally as the data requires, and improves upon previous retrieval experiments in the brown dwarf regime by allowing for scattering in two stream radiative transfer. Our first application of the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.01257v2-abstract-full').style.display = 'inline'; document.getElementById('1701.01257v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1701.01257v2-abstract-full" style="display: none;"> We present the first results from applying the spectral inversion technique in the cloudy L dwarf regime. Our new framework provides a flexible approach to modelling cloud opacity which can be built incrementally as the data requires, and improves upon previous retrieval experiments in the brown dwarf regime by allowing for scattering in two stream radiative transfer. Our first application of the tool to two mid-L dwarfs is able to reproduce their near-infrared spectra far more closely than grid models. Our retrieved thermal, chemical, and cloud profiles allow us to estimate $T_{\rm eff} = 1796^{+23}_{-25}$ K and $\log g = 5.21^{+0.05}_{-0.08}$ for 2MASS J05002100+0330501 and for 2MASSW J2224438-015852 we find $T_{\rm eff} = 1723^{+18}_{-19}$ K and $\log g = 5.31^{+0.04}_{-0.08}$, in close agreement with previous empirical estimates. Our best model for both objects includes an optically thick cloud deck which passes $蟿_{cloud} \geq 1$ (looking down) at a pressure of around 5 bar. The temperature at this pressure is too high for silicate species to condense, and we argue that corundum and/or iron clouds are responsible for this cloud opacity. Our retrieved profiles are cooler at depth, and warmer at altitude than the forward grid models that we compare, and we argue that some form of heating mechanism may be at work in the upper atmospheres of these L dwarfs. We also identify anomalously high CO abundance in both targets, which does not correlate with the warmth of our upper atmospheres or our choice of cloud model, and find similarly anomalous alkali abundance for one of our targets. These anomalies may reflect unrecognised shortcomings in our retrieval model, or inaccuracies in our gas phase opacities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1701.01257v2-abstract-full').style.display = 'none'; document.getElementById('1701.01257v2-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, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 January, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS. Changes in review: additional validation against T dwarf test case, posteriors for cloud free retrievals and contribution functions added to Appendix. Also, entire investigation re-run with new UCL H2O opacities, with minimal impact on results</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1612.02809">arXiv:1612.02809</a> <span> [<a href="https://arxiv.org/pdf/1612.02809">pdf</a>, <a href="https://arxiv.org/format/1612.02809">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="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/10.3847/1538-4357/aa7ff0">10.3847/1538-4357/aa7ff0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Uniform Atmospheric Retrieval Analysis of Ultracool Dwarfs II: Properties of 11 T-dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Line%2C+M+R">Michael R. Line</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">Mark S. Marley</a>, <a href="/search/?searchtype=author&query=Liu%2C+M+C">Michael C. Liu</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">Caroline V. Morley</a>, <a href="/search/?searchtype=author&query=Hinkel%2C+N+R">Natalie R. Hinkel</a>, <a href="/search/?searchtype=author&query=Teske%2C+J">Johanna Teske</a>, <a href="/search/?searchtype=author&query=Fortney%2C+J+J">Jonathan J. Fortney</a>, <a href="/search/?searchtype=author&query=Lupu%2C+R">Roxana Lupu</a>, <a href="/search/?searchtype=author&query=Freedman%2C+R">Richard Freedman</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="1612.02809v3-abstract-short" style="display: inline;"> Brown dwarf spectra are rich in information revealing of the chemical and physical processes operating in their atmospheres. We apply a recently developed atmospheric retrieval tool to an ensemble of late T-dwarf (600-800K) near infrared spectra. With these spectra we are able to place direct constraints the molecular abundances of H$_2$O, CH$_4$, CO, CO$_2$, NH$_3$, H$_2$S, and Na+K, gravity, the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.02809v3-abstract-full').style.display = 'inline'; document.getElementById('1612.02809v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1612.02809v3-abstract-full" style="display: none;"> Brown dwarf spectra are rich in information revealing of the chemical and physical processes operating in their atmospheres. We apply a recently developed atmospheric retrieval tool to an ensemble of late T-dwarf (600-800K) near infrared spectra. With these spectra we are able to place direct constraints the molecular abundances of H$_2$O, CH$_4$, CO, CO$_2$, NH$_3$, H$_2$S, and Na+K, gravity, thermal structure (and effective temperature), photometric radius, and cloud optical depths. We find that ammonia, water, methane, and the alkali metals are present and well constrained in all 11 objects. From the abundance constraints we find no significant trend in the water, methane, or ammonia abundances with temperature, but find a very strong ($>$25$蟽$) increasing trend in the alkali metal abundances with effective temperature, indicative of alkali rainout. We also find little evidence for optically thick clouds. With the methane and water abundances, we derive the intrinsic atmospheric metallicity and carbon-to-oxygen ratios. We find in our sample, that metallicities are typically sub solar and carbon-to-oxygen ratios are somewhat super solar, different than expectations from the local stellar population. We also find that the retrieved vertical thermal profiles are consistent with radiative equilibrium over the photospheric regions. Finally, we find that our retrieved effective temperatures are lower than previous inferences for some objects and that our radii are larger than expectations from evolutionary models, possibly indicative of un-resolved binaries. This investigation and methodology represents a paradigm in linking spectra to the determination of the fundamental chemical and physical processes governing cool brown dwarf atmospheres. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.02809v3-abstract-full').style.display = 'none'; document.getElementById('1612.02809v3-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 July, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2016. </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 ApJ. Supplemental material including full posteriors will be included through the link in the published ApJ article</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1609.07181">arXiv:1609.07181</a> <span> [<a href="https://arxiv.org/pdf/1609.07181">pdf</a>, <a href="https://arxiv.org/format/1609.07181">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stw2438">10.1093/mnras/stw2438 <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. I. Six new L subdwarfs, classification and atmospheric properties </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Galvez-Ortiz%2C+M+C">M. C. Galvez-Ortiz</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Allard%2C+F">F. Allard</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Homeier%2C+D">D. Homeier</a>, <a href="/search/?searchtype=author&query=Gomes%2C+J">J. Gomes</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</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="1609.07181v2-abstract-short" style="display: inline;"> We have conducted a search for L subdwarf candidates within the photometric catalogues of the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Six of our candidates are confirmed as L subdwarfs spectroscopically at optical and/or near infrared wavelengths. We also present new optical spectra of three previously known L subdwarfs (WISEA J001450.17-083823.4, 2MASS J00412179+3547133, ULAS… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1609.07181v2-abstract-full').style.display = 'inline'; document.getElementById('1609.07181v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1609.07181v2-abstract-full" style="display: none;"> We have conducted a search for L subdwarf candidates within the photometric catalogues of the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Six of our candidates are confirmed as L subdwarfs spectroscopically at optical and/or near infrared wavelengths. We also present new optical spectra of three previously known L subdwarfs (WISEA J001450.17-083823.4, 2MASS J00412179+3547133, ULAS J124425.75+102439.3). We examined the spectral types and metallicity subclasses classification of known L subdwarfs. We summarised the spectroscopic properties of L subdwarfs with different spectral types and subclasses. We classify these new L subdwarfs by comparing their spectra to known L subdwarfs and L dwarf standards. We estimate temperatures and metallicities of 22 late type M and L subdwarfs by comparing their spectra to BT-Settl models. We find that L subdwarfs have temperatures between 1500 K and 2700 K, which are higher than similarly-typed L dwarfs by around 100-400 K depending on different subclasses and subtypes. We constrained the metallicity ranges of subclasses of M, L and T subdwarfs. We also discussed the spectral type and absolute magnitude relationships for L and T subdwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1609.07181v2-abstract-full').style.display = 'none'; document.getElementById('1609.07181v2-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 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 September, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 22 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/1608.03852">arXiv:1608.03852</a> <span> [<a href="https://arxiv.org/pdf/1608.03852">pdf</a>, <a href="https://arxiv.org/format/1608.03852">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="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/10.1093/mnras/stw2065">10.1093/mnras/stw2065 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A LOFAR mini-survey for low-frequency radio emission from the nearest brown dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Hardcastle%2C+M">M. Hardcastle</a>, <a href="/search/?searchtype=author&query=Nichols%2C+J+D">J. D. Nichols</a>, <a href="/search/?searchtype=author&query=Casewell%2C+S+L">S. L. Casewell</a>, <a href="/search/?searchtype=author&query=Littlefair%2C+S+P">S. P. Littlefair</a>, <a href="/search/?searchtype=author&query=Stark%2C+C">C. Stark</a>, <a href="/search/?searchtype=author&query=Burleigh%2C+M+R">M. R. Burleigh</a>, <a href="/search/?searchtype=author&query=Metchev%2C+S">S. Metchev</a>, <a href="/search/?searchtype=author&query=Tannock%2C+M+E">M. E. Tannock</a>, <a href="/search/?searchtype=author&query=van+Weeren%2C+R+J">R. J. van Weeren</a>, <a href="/search/?searchtype=author&query=Williams%2C+W+L">W. L. Williams</a>, <a href="/search/?searchtype=author&query=Wynn%2C+G+A">G. A. Wynn</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="1608.03852v1-abstract-short" style="display: inline;"> We have conducted a mini-survey for low-frequency radio emission from some of the closest brown dwarfs to the Sun with rapid rotation rates: SIMP J013656.5+093347, WISEPC J150649.97+702736.0, and WISEPA J174124.26+255319.5. We have placed robust 3-sigma upper limits on the flux density in the 111 - 169 MHz frequency range for these targets: WISE 1506: < 0.72 mJy; WISE 1741: < 0.87 mJy; SIMP 0136:… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.03852v1-abstract-full').style.display = 'inline'; document.getElementById('1608.03852v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1608.03852v1-abstract-full" style="display: none;"> We have conducted a mini-survey for low-frequency radio emission from some of the closest brown dwarfs to the Sun with rapid rotation rates: SIMP J013656.5+093347, WISEPC J150649.97+702736.0, and WISEPA J174124.26+255319.5. We have placed robust 3-sigma upper limits on the flux density in the 111 - 169 MHz frequency range for these targets: WISE 1506: < 0.72 mJy; WISE 1741: < 0.87 mJy; SIMP 0136: < 0.66 mJy. At 8 hours of integration per target to achieve these limits, we find that systematic and detailed study of this class of object at LOFAR frequencies will require a substantial dedication of resources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.03852v1-abstract-full').style.display = 'none'; document.getElementById('1608.03852v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2016. </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. MNRAS accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1601.03402">arXiv:1601.03402</a> <span> [<a href="https://arxiv.org/pdf/1601.03402">pdf</a>, <a href="https://arxiv.org/format/1601.03402">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> <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/10.1093/mnras/stw061">10.1093/mnras/stw061 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Method for Selecting M dwarfs with an Increased Likelihood of Unresolved Ultra-cool Companionship </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cook%2C+N+J">N. J. Cook</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Frith%2C+J">J. Frith</a>, <a href="/search/?searchtype=author&query=Zhong%2C+J">J. Zhong</a>, <a href="/search/?searchtype=author&query=Luo%2C+A+L">A. L. Luo</a>, <a href="/search/?searchtype=author&query=Qi%2C+Z+X">Z. X. Qi</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Kurtev%2C+R+G">R. G. Kurtev</a>, <a href="/search/?searchtype=author&query=Guo%2C+Y+X">Y. X. Guo</a>, <a href="/search/?searchtype=author&query=Wang%2C+Y+F">Y. F. Wang</a>, <a href="/search/?searchtype=author&query=Bai%2C+Y">Y. Bai</a>, <a href="/search/?searchtype=author&query=Yi%2C+Z+P">Z. P. Yi</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</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="1601.03402v1-abstract-short" style="display: inline;"> Locating ultra-cool companions to M dwarfs is important for constraining low-mass formation models, the measurement of sub-stellar dynamical masses and radii, and for testing ultra-cool evolutionary models. We present an optimised method for identifying M dwarfs which may have unresolved ultra-cool companions. We construct a catalogue of 440,694 candidates, from WISE, 2MASS and SDSS, based on opti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.03402v1-abstract-full').style.display = 'inline'; document.getElementById('1601.03402v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1601.03402v1-abstract-full" style="display: none;"> Locating ultra-cool companions to M dwarfs is important for constraining low-mass formation models, the measurement of sub-stellar dynamical masses and radii, and for testing ultra-cool evolutionary models. We present an optimised method for identifying M dwarfs which may have unresolved ultra-cool companions. We construct a catalogue of 440,694 candidates, from WISE, 2MASS and SDSS, based on optical and near-infrared colours and reduced proper motion. With strict reddening, photometric and quality constraints we isolate a sub-sample of 36,898 M dwarfs and search for possible mid-infrared M dwarf + ultra-cool dwarf candidates by comparing M dwarfs which have similar optical/near-infrared colours (chosen for their sensitivity to effective temperature and metallicity). We present 1,082 M dwarf + ultra-cool dwarf candidates for follow-up. Using simulated ultra-cool dwarf companions to M dwarfs, we estimate that the occurrence of unresolved ultra-cool companions amongst our M dwarf + ultra-cool dwarf candidates should be at least four times the average for our full M dwarf catalogue. We discuss possible contamination and bias and predict yields of candidates based on our simulations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.03402v1-abstract-full').style.display = 'none'; document.getElementById('1601.03402v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 January, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2016. </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, 10 figures, (9 pages of appendices) accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1509.09226">arXiv:1509.09226</a> <span> [<a href="https://arxiv.org/pdf/1509.09226">pdf</a>, <a href="https://arxiv.org/ps/1509.09226">ps</a>, <a href="https://arxiv.org/format/1509.09226">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stv2290">10.1093/mnras/stv2290 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery of a brown dwarf companion to the A3V star 尾 Circini </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Smith%2C+L+C">L. C. Smith</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Pe%C3%B1a%2C+C+C">C. Contreras Pe帽a</a>, <a href="/search/?searchtype=author&query=Kurtev%2C+R">R. Kurtev</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Beamin%2C+J+C">J. C. Beamin</a>, <a href="/search/?searchtype=author&query=Napiwotzki%2C+R">R. Napiwotzki</a>, <a href="/search/?searchtype=author&query=Borissova%2C+J">J. Borissova</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J">J. Faherty</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/?searchtype=author&query=Ivanov%2C+V+D">V. D. Ivanov</a>, <a href="/search/?searchtype=author&query=Minniti%2C+D">D. Minniti</a>, <a href="/search/?searchtype=author&query=Stimson%2C+W">W. Stimson</a>, <a href="/search/?searchtype=author&query=Villanueva%2C+V">V. Villanueva</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="1509.09226v1-abstract-short" style="display: inline;"> We report the discovery of an L dwarf companion to the A3V star 尾 Circini. VVV J151721.49-585131.5, or 尾 Cir B, was identified in a proper motion and parallax catalogue of the Vista Variables in the V铆a L谩ctea survey as having near infrared luminosity and colour indicative of an early L dwarf, and a proper motion and parallax consistent with that of 尾 Cir. The projected separation of $\sim$3.6' co… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1509.09226v1-abstract-full').style.display = 'inline'; document.getElementById('1509.09226v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1509.09226v1-abstract-full" style="display: none;"> We report the discovery of an L dwarf companion to the A3V star 尾 Circini. VVV J151721.49-585131.5, or 尾 Cir B, was identified in a proper motion and parallax catalogue of the Vista Variables in the V铆a L谩ctea survey as having near infrared luminosity and colour indicative of an early L dwarf, and a proper motion and parallax consistent with that of 尾 Cir. The projected separation of $\sim$3.6' corresponds to $6656$ au, which is unusually wide. The most recent published estimate of the age of the primary combined with our own estimate based on newer isochrones yields an age of $370-500$ Myr. The system therefore serves as a useful benchmark at an age greater than that of the Pleiades brown dwarfs and most other young L dwarf benchmarks. We have obtained a medium resolution echelle spectrum of the companion which indicates a spectral type of L1.0$\pm$0.5 and lacks the typical signatures of low surface gravity seen in younger brown dwarfs. This suggests that signs of low surface gravity disappear from the spectra of early L dwarfs by an age of $\sim370-500$ Myr, as expected from theoretical isochrones. The mass of 尾 Cir B is estimated from the BHAC15 isochrones as $0.056\pm0.007$ M$_{\odot}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1509.09226v1-abstract-full').style.display = 'none'; document.getElementById('1509.09226v1-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, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2015. </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 MNRAS main 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/1508.03084">arXiv:1508.03084</a> <span> [<a href="https://arxiv.org/pdf/1508.03084">pdf</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/10.1126/science.aac5891">10.1126/science.aac5891 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Macintosh%2C+B">B. Macintosh</a>, <a href="/search/?searchtype=author&query=Graham%2C+J+R">J. R. Graham</a>, <a href="/search/?searchtype=author&query=Barman%2C+T">T. Barman</a>, <a href="/search/?searchtype=author&query=De+Rosa%2C+R+J">R. J. De Rosa</a>, <a href="/search/?searchtype=author&query=Konopacky%2C+Q">Q. Konopacky</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">M. S. Marley</a>, <a href="/search/?searchtype=author&query=Marois%2C+C">C. Marois</a>, <a href="/search/?searchtype=author&query=Nielsen%2C+E+L">E. L. Nielsen</a>, <a href="/search/?searchtype=author&query=Pueyo%2C+L">L. Pueyo</a>, <a href="/search/?searchtype=author&query=Rajan%2C+A">A. Rajan</a>, <a href="/search/?searchtype=author&query=Rameau%2C+J">J. Rameau</a>, <a href="/search/?searchtype=author&query=Saumon%2C+D">D. Saumon</a>, <a href="/search/?searchtype=author&query=Wang%2C+J+J">J. J. Wang</a>, <a href="/search/?searchtype=author&query=Patience%2C+J">J. Patience</a>, <a href="/search/?searchtype=author&query=Ammons%2C+M">M. Ammons</a>, <a href="/search/?searchtype=author&query=Arriaga%2C+P">P. Arriaga</a>, <a href="/search/?searchtype=author&query=Artigau%2C+E">E. Artigau</a>, <a href="/search/?searchtype=author&query=Beckwith%2C+S">S. Beckwith</a>, <a href="/search/?searchtype=author&query=Brewster%2C+J">J. Brewster</a>, <a href="/search/?searchtype=author&query=Bruzzone%2C+S">S. Bruzzone</a>, <a href="/search/?searchtype=author&query=Bulger%2C+J">J. Bulger</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Burrows%2C+A+S">A. S. Burrows</a>, <a href="/search/?searchtype=author&query=Chen%2C+C">C. Chen</a>, <a href="/search/?searchtype=author&query=Chiang%2C+E">E. Chiang</a> , et al. (63 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="1508.03084v2-abstract-short" style="display: inline;"> Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric composition and luminosity, which is influenced by their formation mechanism. Using the Gemini Planet Imager, we discovered a planet orbiting the \$sim$20 Myr-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.03084v2-abstract-full').style.display = 'inline'; document.getElementById('1508.03084v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1508.03084v2-abstract-full" style="display: none;"> Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric composition and luminosity, which is influenced by their formation mechanism. Using the Gemini Planet Imager, we discovered a planet orbiting the \$sim$20 Myr-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water vapor absorption. Modeling of the spectra and photometry yields a luminosity of L/LS=1.6-4.0 x 10-6 and an effective temperature of 600-750 K. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold- start" core accretion process that may have formed Jupiter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.03084v2-abstract-full').style.display = 'none'; document.getElementById('1508.03084v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 October, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 August, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2015. </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, 3 figures, 2 tables, and Supplementary Materials. published in Science Express on Aug 13 2015. List of authors and the magnitudes of the star were correted</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macintosh et al., Science 350 (6256): 64-67, 2015 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1505.01923">arXiv:1505.01923</a> <span> [<a href="https://arxiv.org/pdf/1505.01923">pdf</a>, <a href="https://arxiv.org/format/1505.01923">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="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Results from the Wide-field Infrared Survey Explorer (WISE) Future Uses Session at the WISE at 5 Meeting </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Faherty%2C+J+K">Jacqueline K. Faherty</a>, <a href="/search/?searchtype=author&query=Alatalo%2C+K">K. Alatalo</a>, <a href="/search/?searchtype=author&query=Anderson%2C+L+D">L. D. Anderson</a>, <a href="/search/?searchtype=author&query=Assef%2C+R+J">Roberto J. Assef</a>, <a href="/search/?searchtype=author&query=Gagliuffi%2C+D+C+B">Daniella C. Bardalez Gagliuffi</a>, <a href="/search/?searchtype=author&query=Barry%2C+M">Megan Barry</a>, <a href="/search/?searchtype=author&query=Benford%2C+D+J">Dominic J. Benford</a>, <a href="/search/?searchtype=author&query=Bilicki%2C+M">Maciej Bilicki</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Christian%2C+D+J">Damian J. Christian</a>, <a href="/search/?searchtype=author&query=Cushing%2C+M+C">Michael C. Cushing</a>, <a href="/search/?searchtype=author&query=Eisenhardt%2C+P+R">Peter R. Eisenhardt</a>, <a href="/search/?searchtype=author&query=Elvisx%2C+M">Martin Elvisx</a>, <a href="/search/?searchtype=author&query=Fajardo-Acosta%2C+S+B">S. B. Fajardo-Acosta</a>, <a href="/search/?searchtype=author&query=Finkbeiner%2C+D+P">Douglas P. Finkbeiner</a>, <a href="/search/?searchtype=author&query=Fischer%2C+W+J">William J. Fischer</a>, <a href="/search/?searchtype=author&query=Forrest%2C+W+J">William J. Forrest</a>, <a href="/search/?searchtype=author&query=Fowler%2C+J">John Fowler</a>, <a href="/search/?searchtype=author&query=Gardner%2C+J+P">Jonathan P. Gardner</a>, <a href="/search/?searchtype=author&query=Gelino%2C+C+R">Christopher R. Gelino</a>, <a href="/search/?searchtype=author&query=Gorjian%2C+V">V Gorjian</a>, <a href="/search/?searchtype=author&query=Grillmair%2C+C+J">Carl J. Grillmair</a>, <a href="/search/?searchtype=author&query=Gromadzki%2C+M">Mariusz Gromadzki</a>, <a href="/search/?searchtype=author&query=Hall%2C+K+P">Kendall P. Hall</a>, <a href="/search/?searchtype=author&query=Ivezi%27c%2C+Z">Zeljko Ivezi'c</a> , et al. (29 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="1505.01923v1-abstract-short" style="display: inline;"> During the "WISE at 5: Legacy and Prospects" conference in Pasadena, CA -- which ran from February 10 - 12, 2015 -- attendees were invited to engage in an interactive session exploring the future uses of the Wide-field Infrared Survey Explorer (WISE) data. The 65 participants -- many of whom are extensive users of the data -- brainstormed the top questions still to be answered by the mission, as w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1505.01923v1-abstract-full').style.display = 'inline'; document.getElementById('1505.01923v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1505.01923v1-abstract-full" style="display: none;"> During the "WISE at 5: Legacy and Prospects" conference in Pasadena, CA -- which ran from February 10 - 12, 2015 -- attendees were invited to engage in an interactive session exploring the future uses of the Wide-field Infrared Survey Explorer (WISE) data. The 65 participants -- many of whom are extensive users of the data -- brainstormed the top questions still to be answered by the mission, as well as the complementary current and future datasets and additional processing of WISE/NEOWISE data that would aid in addressing these most important scientific questions. The results were mainly bifurcated between topics related to extragalactic studies (e.g. AGN, QSOs) and substellar mass objects. In summary, participants found that complementing WISE/NEOWISE data with cross-correlated multiwavelength surveys (e.g. SDSS, Pan-STARRS, LSST, Gaia, Euclid, etc.) would be highly beneficial for all future mission goals. Moreover, developing or implementing machine-learning tools to comb through and understand cross-correlated data was often mentioned for future uses. Finally, attendees agreed that additional processing of the data such as co-adding WISE and NEOWISE and extracting a multi-epoch photometric database and parallax and proper motion catalog would greatly improve the scientific results of the most important projects identified. In that respect, a project such as MaxWISE which would execute the most important additional processing and extraction as well as make the data and catalogs easily accessible via a public portal was deemed extremely important. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1505.01923v1-abstract-full').style.display = 'none'; document.getElementById('1505.01923v1-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 May, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2015. </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</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1504.06670">arXiv:1504.06670</a> <span> [<a href="https://arxiv.org/pdf/1504.06670">pdf</a>, <a href="https://arxiv.org/format/1504.06670">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="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/10.1088/0004-637X/807/2/183">10.1088/0004-637X/807/2/183 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Uniform Atmospheric Retrieval Analysis of Ultracool Dwarfs I: Characterizing Benchmarks, Gl570D and HD3651B </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Line%2C+M+R">Michael R. Line</a>, <a href="/search/?searchtype=author&query=Teske%2C+J">Johanna Teske</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Fortney%2C+J">Jonathan Fortney</a>, <a href="/search/?searchtype=author&query=Marley%2C+M">Mark Marley</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="1504.06670v2-abstract-short" style="display: inline;"> Interpreting the spectra of brown dwarfs is key to determining the fundamental physical and chemical processes occurring in their atmospheres. Powerful Bayesian atmospheric retrieval tools have recently been applied to both exoplanet and brown dwarf spectra to tease out the thermal structures and molecular abundances to understand those processes. In this manuscript we develop a significantly upgr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.06670v2-abstract-full').style.display = 'inline'; document.getElementById('1504.06670v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1504.06670v2-abstract-full" style="display: none;"> Interpreting the spectra of brown dwarfs is key to determining the fundamental physical and chemical processes occurring in their atmospheres. Powerful Bayesian atmospheric retrieval tools have recently been applied to both exoplanet and brown dwarf spectra to tease out the thermal structures and molecular abundances to understand those processes. In this manuscript we develop a significantly upgraded retrieval method and apply it to the SpeX spectral library data of two benchmark late T-dwarfs, Gl570D and HD3651B, to establish the validity of our upgraded forward model parameterization and Bayesian estimator. Our retrieved metallicities, gravities, and effective temperature are consistent with the metallicity and presumed ages of the systems. We add the carbon-to-oxygen ratio as a new dimension to benchmark systems and find good agreement between carbon-to-oxygens ratio derived in the brown dwarfs and the host stars. Furthermore, we have for the first time unambiguously determined the presence of ammonia in the low-resolution spectra of these two late T-dwarfs. We also show that the retrieved results are not significantly impacted by the possible presence of clouds, though some quantities are significantly impacted by uncertainties in photometry. This investigation represents a watershed study in establishing the utility of atmospheric retrieval approaches on brown dwarf spectra. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.06670v2-abstract-full').style.display = 'none'; document.getElementById('1504.06670v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 May, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 April, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted to Apj, addressed first round of minor revisions</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1503.05082">arXiv:1503.05082</a> <span> [<a href="https://arxiv.org/pdf/1503.05082">pdf</a>, <a href="https://arxiv.org/ps/1503.05082">ps</a>, <a href="https://arxiv.org/format/1503.05082">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stv530">10.1093/mnras/stv530 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A large spectroscopic sample of L and T dwarfs from UKIDSS LAS: peculiar objects, binaries, and space density </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Gomes%2C+J+I">J. I. Gomes</a>, <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</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="1503.05082v1-abstract-short" style="display: inline;"> We present the spectroscopic analysis of a large sample of late-M, L, and T dwarfs from UKIDSS. Using the YJHK photometry from ULAS and the red-optical photometry from SDSS we selected a sample of 262 brown dwarf candidates and we followed-up 196 of them using X-shooter on the VLT. The large wavelength coverage (0.30-2.48 $渭$m) and moderate resolution (R~5000-9000) of X-shooter allowed us to ident… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.05082v1-abstract-full').style.display = 'inline'; document.getElementById('1503.05082v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1503.05082v1-abstract-full" style="display: none;"> We present the spectroscopic analysis of a large sample of late-M, L, and T dwarfs from UKIDSS. Using the YJHK photometry from ULAS and the red-optical photometry from SDSS we selected a sample of 262 brown dwarf candidates and we followed-up 196 of them using X-shooter on the VLT. The large wavelength coverage (0.30-2.48 $渭$m) and moderate resolution (R~5000-9000) of X-shooter allowed us to identify peculiar objects including 22 blue L dwarfs, 2 blue T dwarfs, and 2 low gravity M dwarfs. Using a spectral indices-based technique we identified 27 unresolved binary candidates, for which we determined the spectral type of the potential components via spectral deconvolution. The spectra allowed us to measure the equivalent width of the prominent absorption features and to compare them to atmospheric models. Cross-correlating the spectra with a radial velocity standard, we measured the radial velocity for our targets, and we determined the distribution of the sample, which is centred at -1.7$\pm$1.2 km s$^{-1}$ with a dispersion of 31.5 km s$^{-1}$. Using our results we estimated the space density of field brown dwarfs and compared it with the results of numerical simulations. Depending on the binary fraction, we found that there are (0.85$\pm$0.55) x 10$^{-3}$ to (1.00$\pm$0.64) x 10$^{-3}$ objects per cubic parsec in the L4-L6.5 range, (0.73$\pm$0.47) x 10$^{-3}$ to (0.85$\pm$0.55) x 10$^{-3}$ objects per cubic parsec in the L7-T0.5 range, and (0.74$\pm$0.48) x 10$^{-3}$ to (0.88$\pm$0.56) x 10$^{-3}$ objects per cubic parsec in the T1-T4.5 range. There seem to be an excess of objects in the L/T transition with respect to the late T dwarfs, a discrepancy that could be explained assuming a higher binary fraction than expected for the L/T transition, or that objects in the high-mass end and low-mass end of this regime form in different environments, i.e. following different IMFs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.05082v1-abstract-full').style.display = 'none'; document.getElementById('1503.05082v1-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 March, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2015. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1503.04715">arXiv:1503.04715</a> <span> [<a href="https://arxiv.org/pdf/1503.04715">pdf</a>, <a href="https://arxiv.org/format/1503.04715">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stv586">10.1093/mnras/stv586 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Methane and Ammonia in the near-infrared spectra of late T dwarfs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Canty%2C+J+I">J. I. Canty</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Yurchenko%2C+S+N">Sergei N. Yurchenko</a>, <a href="/search/?searchtype=author&query=Tennyson%2C+J">Jonathan Tennyson</a>, <a href="/search/?searchtype=author&query=Leggett%2C+S+K">S. K. Leggett</a>, <a href="/search/?searchtype=author&query=Tinney%2C+C+G">C. G. Tinney</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</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="1503.04715v1-abstract-short" style="display: inline;"> Analysis of T dwarfs using model atmospheres has been hampered by the absence of reliable line lists for methane and ammonia. Newly computed high temperature line lists for both of these important molecules are now available, so it is timely to investigate the appearance of the various absorption features in T dwarfs in order to better understand their atmospheres and validate the new line lists.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.04715v1-abstract-full').style.display = 'inline'; document.getElementById('1503.04715v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1503.04715v1-abstract-full" style="display: none;"> Analysis of T dwarfs using model atmospheres has been hampered by the absence of reliable line lists for methane and ammonia. Newly computed high temperature line lists for both of these important molecules are now available, so it is timely to investigate the appearance of the various absorption features in T dwarfs in order to better understand their atmospheres and validate the new line lists. We present high quality R~5000 Gemini/NIFS 1.0-2.4 microns spectra of the T8 standard 2MASS 0415-0935 and the T9 standard UGPS 0722-0540. We use these spectra to identify numerous methane and ammonia features not previously seen and we discuss the implications for our understanding of T dwarf atmospheres. Among our results, we find that ammonia is the dominant opacity source between ~1.233-1.266 microns in UGPS 0722-0540, and we tentatively identify several absorption features in this wavelength range in the T9's spectrum which may be due entirely to ammonia opacity. Our results also suggest that water rather than methane is the dominant opacity source in the red half of the J-band of the T8 dwarf. Water appears to be the main absorber in this wavelength region in the T9 dwarf until ~1.31 microns, when methane starts to dominate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.04715v1-abstract-full').style.display = 'none'; document.getElementById('1503.04715v1-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 March, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2015. </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, 37 figures, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1502.06503">arXiv:1502.06503</a> <span> [<a href="https://arxiv.org/pdf/1502.06503">pdf</a>, <a href="https://arxiv.org/format/1502.06503">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stv380">10.1093/mnras/stv380 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> 49 new T dwarfs identified using methane imaging </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cardoso%2C+C+V">C. V. Cardoso</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=van+Spaandonk%2C+L">L. van Spaandonk</a>, <a href="/search/?searchtype=author&query=Baker%2C+D">D. Baker</a>, <a href="/search/?searchtype=author&query=Smith%2C+L+C">L. C. Smith</a>, <a href="/search/?searchtype=author&query=Andrei%2C+A+H">A. H. Andrei</a>, <a href="/search/?searchtype=author&query=Bucciarelli%2C+B">B. Bucciarelli</a>, <a href="/search/?searchtype=author&query=Dhital%2C+S">S. Dhital</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Lattanzi%2C+M+G">M. G. Lattanzi</a>, <a href="/search/?searchtype=author&query=Magazzu%2C+A">A. Magazzu</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Tinney%2C+C+G">C. G. Tinney</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="1502.06503v1-abstract-short" style="display: inline;"> We present the discovery of 49 new photometrically classified T dwarfs from the combination of large infrared and optical surveys combined with follow-up TNG photometry. We used multi-band infrared and optical photometry from the UKIRT and Sloan Digital Sky Surveys to identify possible brown dwarf candidates, which were then confirmed using methane filter photometry. We have defined a new photomet… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1502.06503v1-abstract-full').style.display = 'inline'; document.getElementById('1502.06503v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1502.06503v1-abstract-full" style="display: none;"> We present the discovery of 49 new photometrically classified T dwarfs from the combination of large infrared and optical surveys combined with follow-up TNG photometry. We used multi-band infrared and optical photometry from the UKIRT and Sloan Digital Sky Surveys to identify possible brown dwarf candidates, which were then confirmed using methane filter photometry. We have defined a new photometric conversion between CH4s - CH4l colour and spectral type for T4 to T8 brown dwarfs based on a part of the sample that has been followed up using methane photometry and spectroscopy. Using methane differential photometry as a proxy for spectral type for T dwarfs has proved to be a very efficient technique. Of a subset of 45 methane selected brown dwarfs that were observed spectroscopically, 100% were confirmed as T dwarfs. Future deep imaging surveys will produce large samples of faint brown dwarf candidates, for which spectroscopy will not be feasible. When broad wavelength coverage is unavailable, methane imaging offers a means to efficiently classify candidates from such surveys using just a pair of near-infrared images. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1502.06503v1-abstract-full').style.display = 'none'; document.getElementById('1502.06503v1-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 February, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 5 figures. MNRAS accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1409.3125">arXiv:1409.3125</a> <span> [<a href="https://arxiv.org/pdf/1409.3125">pdf</a>, <a href="https://arxiv.org/format/1409.3125">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stu1895">10.1093/mnras/stu1895 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The substellar companion in the eclipsing white dwarf binary SDSS J141126.20+200911.1 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Littlefair%2C+S+P">S. P. Littlefair</a>, <a href="/search/?searchtype=author&query=Casewell%2C+S+L">S. L. Casewell</a>, <a href="/search/?searchtype=author&query=Parsons%2C+S+G">S. G. Parsons</a>, <a href="/search/?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/?searchtype=author&query=Marsh%2C+T+R">T. R. Marsh</a>, <a href="/search/?searchtype=author&query=Gaensicke%2C+B+T+G">B. T. G. Gaensicke</a>, <a href="/search/?searchtype=author&query=Bloemen%2C+S">S. Bloemen</a>, <a href="/search/?searchtype=author&query=Catalan%2C+S">S. Catalan</a>, <a href="/search/?searchtype=author&query=Irawati%2C+P">P. Irawati</a>, <a href="/search/?searchtype=author&query=Hardy%2C+L+K">L. K. Hardy</a>, <a href="/search/?searchtype=author&query=Mcallister%2C+M">M. Mcallister</a>, <a href="/search/?searchtype=author&query=Bours%2C+M+C+P">M. C. P. Bours</a>, <a href="/search/?searchtype=author&query=Richichi%2C+A">Andrea Richichi</a>, <a href="/search/?searchtype=author&query=Burleigh%2C+M+R">M. R. Burleigh</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Breedt%2C+E">E. Breedt</a>, <a href="/search/?searchtype=author&query=Kerry%2C+P">P. Kerry</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="1409.3125v1-abstract-short" style="display: inline;"> We present high time resolution SDSS-$g'$ and SDSS-$z'$ light curves of the primary eclipse in SDSS J141126.20+200911.1, together with time-resolved X-Shooter spectroscopy and near-infrared $JHK_{s}$ photometry. Our observations confirm the substellar nature of the companion, making SDSS J141126.20+200911.1 the first eclipsing white dwarf/brown dwarf binary known. We measure a (white dwarf model d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1409.3125v1-abstract-full').style.display = 'inline'; document.getElementById('1409.3125v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1409.3125v1-abstract-full" style="display: none;"> We present high time resolution SDSS-$g'$ and SDSS-$z'$ light curves of the primary eclipse in SDSS J141126.20+200911.1, together with time-resolved X-Shooter spectroscopy and near-infrared $JHK_{s}$ photometry. Our observations confirm the substellar nature of the companion, making SDSS J141126.20+200911.1 the first eclipsing white dwarf/brown dwarf binary known. We measure a (white dwarf model dependent) mass and radius for the brown dwarf companion of $M_{2} = 0.050 \pm 0.002$ $M_{\odot}$ and $R_{2} = 0.072 \pm 0.004$ $M_{\odot}$, respectively. The lack of a robust detection of the companion light in the $z'$-band eclipse constrains the spectral type of the companion to be later than L5. Comparing the NIR photometry to the expected white dwarf flux reveals a clear $K_s$-band excess, suggesting a spectral type in the range L7-T1. The radius measurement is consistent with the predictions of evolutionary models, and suggests a system age in excess of three Gyr. The low companion mass is inconsistent with the inferred spectral type of L7-T1, instead predicting a spectral type nearer T5. This indicates that irradiation of the companion in SDSS J1411 could be causing a significant temperature increase, at least on one hemisphere. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1409.3125v1-abstract-full').style.display = 'none'; document.getElementById('1409.3125v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 September, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2014. </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, 10 figures, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1408.0284">arXiv:1408.0284</a> <span> [<a href="https://arxiv.org/pdf/1408.0284">pdf</a>, <a href="https://arxiv.org/ps/1408.0284">ps</a>, <a href="https://arxiv.org/format/1408.0284">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stu1540">10.1093/mnras/stu1540 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery of a new Y dwarf: WISE J030449.03-270508.3 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/?searchtype=author&query=Leggett%2C+S+K">S. K. Leggett</a>, <a href="/search/?searchtype=author&query=Gomes%2C+J">J. Gomes</a>, <a href="/search/?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/?searchtype=author&query=Kurtev%2C+R">R. Kurtev</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Ruiz%2C+M+T">M. T. Ruiz</a>, <a href="/search/?searchtype=author&query=Cook%2C+N+J">N. J. Cook</a>, <a href="/search/?searchtype=author&query=Morley%2C+C+V">C. V. Morley</a>, <a href="/search/?searchtype=author&query=Marley%2C+M+S">M. S. Marley</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Beletsky%2C+Y">Y. Beletsky</a>, <a href="/search/?searchtype=author&query=Ivanov%2C+V+D">V. D. Ivanov</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+S">J. S. Jenkins</a>, <a href="/search/?searchtype=author&query=Cardoso%2C+C">C. Cardoso</a>, <a href="/search/?searchtype=author&query=Frith%2C+J">J. Frith</a>, <a href="/search/?searchtype=author&query=Clarke%2C+J+R+A">J. R. A. Clarke</a>, <a href="/search/?searchtype=author&query=Galvez-Ortiz%2C+M+C">M. C. Galvez-Ortiz</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Z">Z. Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1408.0284v1-abstract-short" style="display: inline;"> We present a new Y dwarf, WISE J030449.03-270508.3, confirmed from a candidate sample designed to pick out low temperature objects from the WISE database. The new object is typed Y0pec following a visual comparison with spectral standards, and lies at a likely distance of 10-17 pc. Its tangential velocity suggests thin disk membership, but it shows some spectral characteristics that suggest it may… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1408.0284v1-abstract-full').style.display = 'inline'; document.getElementById('1408.0284v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1408.0284v1-abstract-full" style="display: none;"> We present a new Y dwarf, WISE J030449.03-270508.3, confirmed from a candidate sample designed to pick out low temperature objects from the WISE database. The new object is typed Y0pec following a visual comparison with spectral standards, and lies at a likely distance of 10-17 pc. Its tangential velocity suggests thin disk membership, but it shows some spectral characteristics that suggest it may be metal-poor and/or older than previously identified Y0 dwarfs. Based on trends seen for warmer late type T dwarfs, the Y-band flux peak morphology is indicative of sub-solar metallicity, and the enhanced red wing of the J-band flux peak offers evidence for high gravity and/or low metallicity (with associated model trends suggesting an age closer to ~10 Gyr and mass in the range 0.02-0.03 Mo). This object may thus be extending the population parameter-space of the known Y0 dwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1408.0284v1-abstract-full').style.display = 'none'; document.getElementById('1408.0284v1-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 August, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2014. </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, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1406.6698">arXiv:1406.6698</a> <span> [<a href="https://arxiv.org/pdf/1406.6698">pdf</a>, <a href="https://arxiv.org/ps/1406.6698">ps</a>, <a href="https://arxiv.org/format/1406.6698">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stu1295">10.1093/mnras/stu1295 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High Proper Motion Objects from the UKIDSS Galactic Plane Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Bunce%2C+R">R. Bunce</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Skrzypek%2C+N">N. Skrzypek</a>, <a href="/search/?searchtype=author&query=Rodriguez%2C+D+R">D. R. Rodriguez</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J">J. Faherty</a>, <a href="/search/?searchtype=author&query=Barentsen%2C+G">G. Barentsen</a>, <a href="/search/?searchtype=author&query=Drew%2C+J+E">J. E. Drew</a>, <a href="/search/?searchtype=author&query=Andrei%2C+A+H">A. H. Andrei</a>, <a href="/search/?searchtype=author&query=Catal%C3%A1n%2C+S">S. Catal谩n</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Redburn%2C+D">D. Redburn</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="1406.6698v1-abstract-short" style="display: inline;"> The UKIDSS Galactic Plane Survey (GPS) began in 2005 as a 7 year effort to survey ~1800 square degrees of the northern Galactic plane in the J, H, and K passbands. The survey included a second epoch of K band data, with a baseline of 2 to 8 years, for the purpose of investigating variability and measuring proper motions. We have calculated proper motions for 167 Million sources in a 900 square deg… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1406.6698v1-abstract-full').style.display = 'inline'; document.getElementById('1406.6698v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1406.6698v1-abstract-full" style="display: none;"> The UKIDSS Galactic Plane Survey (GPS) began in 2005 as a 7 year effort to survey ~1800 square degrees of the northern Galactic plane in the J, H, and K passbands. The survey included a second epoch of K band data, with a baseline of 2 to 8 years, for the purpose of investigating variability and measuring proper motions. We have calculated proper motions for 167 Million sources in a 900 square degree area located at l > 60 degrees in order to search for new high proper motion objects. Visual inspection has verified 617 high proper motion sources (> 200 mas/yr) down to K=17, of which 153 are new discoveries. Among these we have a new spectroscopically confirmed T5 dwarf, an additional T dwarf with estimated type T6, 13 new L dwarf candidates, and two new common proper motion systems containing ultracool dwarf candidates. We provide improved proper motions for an additional 12 high proper motion stars that were independently discovered in the WISE dataset during the course of this investigation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1406.6698v1-abstract-full').style.display = 'none'; document.getElementById('1406.6698v1-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 June, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2014. </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 MNRAS main 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/1402.3479">arXiv:1402.3479</a> <span> [<a href="https://arxiv.org/pdf/1402.3479">pdf</a>, <a href="https://arxiv.org/ps/1402.3479">ps</a>, <a href="https://arxiv.org/format/1402.3479">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stu241">10.1093/mnras/stu241 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spectroscopic signatures of youth in low-mass kinematic candidates of young moving groups </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=G%C3%A1lvez-Ortiz%2C+M+C">M. C. G谩lvez-Ortiz</a>, <a href="/search/?searchtype=author&query=Kuznetsov%2C+M">M. Kuznetsov</a>, <a href="/search/?searchtype=author&query=Clarke%2C+J+R+A">J. R. A. Clarke</a>, <a href="/search/?searchtype=author&query=Pavlenko%2C+Y+V">Ya. V. Pavlenko</a>, <a href="/search/?searchtype=author&query=Folkes%2C+S+L">S. L. Folkes</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+S">J. S. Jenkins</a>, <a href="/search/?searchtype=author&query=Barnes%2C+J+R">J. R. Barnes</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Mart%C3%ADn%2C+E+L">E. L. Mart铆n</a>, <a href="/search/?searchtype=author&query=P%C3%A9rez%2C+A+E+G">A. E. Garc铆a P茅rez</a>, <a href="/search/?searchtype=author&query=del+Burgo%2C+C">C. del Burgo</a>, <a href="/search/?searchtype=author&query=Pokorny%2C+R+S">R. S. Pokorny</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="1402.3479v1-abstract-short" style="display: inline;"> We present a study of age-related spectral signatures observed in 25 young low-mass objects that we have previously determined as possible kinematic members of five young moving groups: the Local Association (Pleiades moving group, age=20 - 150 Myr), the Ursa Major group (Sirius supercluster, age=300 Myr), the Hyades supercluster (age=600 Myr), IC 2391 supercluster (age=35--55 Myr) and the Castor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1402.3479v1-abstract-full').style.display = 'inline'; document.getElementById('1402.3479v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1402.3479v1-abstract-full" style="display: none;"> We present a study of age-related spectral signatures observed in 25 young low-mass objects that we have previously determined as possible kinematic members of five young moving groups: the Local Association (Pleiades moving group, age=20 - 150 Myr), the Ursa Major group (Sirius supercluster, age=300 Myr), the Hyades supercluster (age=600 Myr), IC 2391 supercluster (age=35--55 Myr) and the Castor moving group (age=200 Myr). In this paper we characterize the spectral properties of observed high or low resolution spectra of our kinematic members by fitting theoretical spectral distributions. We study signatures of youth, such as lithium {\sc i} 6708 脜, H$伪$ emission and other age-sensitive spectroscopic signatures in order to confirm the kinematic memberships through age constraints. We find that 21 ($84\%$) targets show spectroscopic signatures of youth in agreement with the age ranges of the moving group to which membership is implied. For two further objects, age-related constraints remain difficult to determine from our analysis. In addition, we confirm two moving group kinematic candidates as brown dwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1402.3479v1-abstract-full').style.display = 'none'; document.getElementById('1402.3479v1-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 February, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2014. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1401.5982">arXiv:1401.5982</a> <span> [<a href="https://arxiv.org/pdf/1401.5982">pdf</a>, <a href="https://arxiv.org/ps/1401.5982">ps</a>, <a href="https://arxiv.org/format/1401.5982">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/10.1093/mnras/stu184">10.1093/mnras/stu184 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The discovery of a T6.5 subdwarf </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Burningham%2C+B">Ben Burningham</a>, <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</a>, <a href="/search/?searchtype=author&query=Cardoso%2C+C+V">C. V. Cardoso</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</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="1401.5982v1-abstract-short" style="display: inline;"> We report the discovery of ULAS J131610.28+075553.0, a sdT6.5 dwarf in the UKIDSS Large Area Survey 2 epoch proper motion catalogue. This object displays significant spectral peculiarity, with the largest yet seen deviations from T6 and T7 templates in the Y and K bands for this subtype. Its large, ~1 arcsec/yr, proper motion suggests a large tangential velocity of Vtan = 240 - 340km/s, if we assu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1401.5982v1-abstract-full').style.display = 'inline'; document.getElementById('1401.5982v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1401.5982v1-abstract-full" style="display: none;"> We report the discovery of ULAS J131610.28+075553.0, a sdT6.5 dwarf in the UKIDSS Large Area Survey 2 epoch proper motion catalogue. This object displays significant spectral peculiarity, with the largest yet seen deviations from T6 and T7 templates in the Y and K bands for this subtype. Its large, ~1 arcsec/yr, proper motion suggests a large tangential velocity of Vtan = 240 - 340km/s, if we assume its MJ lies within the typical range for T6.5 dwarfs. This makes it a candidate for membership of the Galactic halo population. However, other metal poor T dwarfs exhibit significant under luminosity both in specific bands and bolometrically. As a result, it is likely that its velocity is somewhat smaller, and we conclude it is a likely thick disc or halo member. This object represents the only T dwarf earlier than T8 to be classified as a subdwarf, and is a significant addition to the currently small number of known unambiguously substellar subdwarfs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1401.5982v1-abstract-full').style.display = 'none'; document.getElementById('1401.5982v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 January, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2014. </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, 5 figures. MNRAS accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1401.0420">arXiv:1401.0420</a> <span> [<a href="https://arxiv.org/pdf/1401.0420">pdf</a>, <a href="https://arxiv.org/ps/1401.0420">ps</a>, <a href="https://arxiv.org/format/1401.0420">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stt2463">10.1093/mnras/stt2463 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The extremely red L dwarf ULAS J222711$-$004547 - dominated by dust </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Z+H">Z. H. Zhang</a>, <a href="/search/?searchtype=author&query=Gomes%2C+J+I">J. I. Gomes</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Raddi%2C+R">R. Raddi</a>, <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1401.0420v1-abstract-short" style="display: inline;"> We report the discovery of a peculiar L dwarf from the UKIDSS LAS, ULAS J222711-004547. The very red infrared photometry (MKO J-K = 2.79$\pm$0.06, WISE W1-W2 = 0.65$\pm$0.05) of ULAS J222711-004547 makes it one of the reddest brown dwarfs discovered so far. We obtained a moderate resolution spectrum of this target, and classify it as L7pec, confirming its very red nature. Comparison to theoretical… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1401.0420v1-abstract-full').style.display = 'inline'; document.getElementById('1401.0420v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1401.0420v1-abstract-full" style="display: none;"> We report the discovery of a peculiar L dwarf from the UKIDSS LAS, ULAS J222711-004547. The very red infrared photometry (MKO J-K = 2.79$\pm$0.06, WISE W1-W2 = 0.65$\pm$0.05) of ULAS J222711-004547 makes it one of the reddest brown dwarfs discovered so far. We obtained a moderate resolution spectrum of this target, and classify it as L7pec, confirming its very red nature. Comparison to theoretical models suggests that the object could be a low-gravity L dwarf with a solar or higher than solar metallicity. Nonetheless, the match of such fits to the spectrum is rather poor and this and other peculiar red L dwarfs pose new challenges for the modeling of ultracool atmospheres. We determined the proper motion of ULAS J222711-004547 using the data available in the literature, and we find that its kinematics do not suggest membership of any of the known young associations. We show that applying a simple de-reddening curve to its spectrum allows it to resemble the spectra of the L7 spectroscopic standards. Given the negligible interstellar reddening of the field containing our target, we conclude that the reddening of the spectrum is mostly due to an excess of dust in the photosphere of the target. De-reddening the spectrum using extinction curves for different dust species gives surprisingly good results and suggests a characteristic grain size of $\sim$0.5 $渭$m. We show that by increasing the optical depth, the same extinction curves allow the spectrum of ULAS J222711-004547 to resemble the spectra of unusually blue L dwarfs and slightly metal-poor L dwarfs. Grains of similar size yield very good fits when de-reddening other unusually red L dwarfs in the L5 to L7.5 range. These results suggest that the diversity in near infrared colours and spectra seen in late-L dwarfs could be due to differences in the optical thickness of the dust cloud deck. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1401.0420v1-abstract-full').style.display = 'none'; document.getElementById('1401.0420v1-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 January, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 3 tables, 15 figures, accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1311.6707">arXiv:1311.6707</a> <span> [<a href="https://arxiv.org/pdf/1311.6707">pdf</a>, <a href="https://arxiv.org/ps/1311.6707">ps</a>, <a href="https://arxiv.org/format/1311.6707">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1086/675072">10.1086/675072 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Parallaxes of five L Dwarfs with a Robotic Telescope </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Wang%2C+Y">Y. Wang</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Shao%2C+Z">Z. Shao</a>, <a href="/search/?searchtype=author&query=Steele%2C+I+A">I. A. Steele</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Z">Z. Zhang</a>, <a href="/search/?searchtype=author&query=Andrei%2C+A+H">A. H. Andrei</a>, <a href="/search/?searchtype=author&query=Burgasser%2C+A+J">A. J. Burgasser</a>, <a href="/search/?searchtype=author&query=Cruz%2C+K+L">K. L. Cruz</a>, <a href="/search/?searchtype=author&query=Yu%2C+J">J. Yu</a>, <a href="/search/?searchtype=author&query=Clarke%2C+J+R+A">J. R. A. Clarke</a>, <a href="/search/?searchtype=author&query=Leigh%2C+C+J">C. J. Leigh</a>, <a href="/search/?searchtype=author&query=Sozzetti%2C+A">A. Sozzetti</a>, <a href="/search/?searchtype=author&query=Murray%2C+D+N">D. N. Murray</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</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="1311.6707v1-abstract-short" style="display: inline;"> We report the parallax and proper motion of five L dwarfs obtained with observations from the robotic Liverpool Telescope. Our derived proper motions are consistent with published values and have considerably smaller errors. Based on our spectral type versus absolute magnitude diagram, we do not find any evidence for binaries among our sample, or, at least no comparable mass binaries. Their space… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1311.6707v1-abstract-full').style.display = 'inline'; document.getElementById('1311.6707v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1311.6707v1-abstract-full" style="display: none;"> We report the parallax and proper motion of five L dwarfs obtained with observations from the robotic Liverpool Telescope. Our derived proper motions are consistent with published values and have considerably smaller errors. Based on our spectral type versus absolute magnitude diagram, we do not find any evidence for binaries among our sample, or, at least no comparable mass binaries. Their space velocities locate them within the thin disk and based on the model comparisons they have solar-like abundances. For all five objects, we derived effective temperature, luminosity, radius, gravity and mass from a evolutionary model(CBA00) and our measured parallax; moreover, we derived their effective temperature by integrating observed optical and near-infrared spectra and model spectra (BSH06 or BT-Dusty respectively) at longer wavelengths to obtain bolometric {\bf flux using} the classical Stefan-Boltzmann law: generally the three temperatures for one object derived using two different methods with three models are consistent, while at lower temperature(e.g. for L4) the differences among the three temperatures are slightly larger than that at higher temperature(e.g. for L1). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1311.6707v1-abstract-full').style.display = 'none'; document.getElementById('1311.6707v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 November, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2013. </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">36 pages, 7 figures, 7 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/1311.1227">arXiv:1311.1227</a> <span> [<a href="https://arxiv.org/pdf/1311.1227">pdf</a>, <a href="https://arxiv.org/ps/1311.1227">ps</a>, <a href="https://arxiv.org/format/1311.1227">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stt2156">10.1093/mnras/stt2156 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A 1500 deg$^2$ Near Infrared Proper Motion Catalogue from the UKIDSS Large Area Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Andrei%2C+A+H">A. H. Andrei</a>, <a href="/search/?searchtype=author&query=Catalan%2C+S">S. Catalan</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D">D. 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="1311.1227v1-abstract-short" style="display: inline;"> The UKIDSS Large Area Survey (LAS) began in 2005, with the start of the UKIDSS program as a 7 year effort to survey roughly 4000 deg$^2$ at high galactic latitudes in Y, J, H and K bands. The survey also included a significant quantity of 2-epoch J band observations, with an epoch baseline greater than 2 years to calculate proper motions. We present a near infrared proper motion catalogue for the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1311.1227v1-abstract-full').style.display = 'inline'; document.getElementById('1311.1227v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1311.1227v1-abstract-full" style="display: none;"> The UKIDSS Large Area Survey (LAS) began in 2005, with the start of the UKIDSS program as a 7 year effort to survey roughly 4000 deg$^2$ at high galactic latitudes in Y, J, H and K bands. The survey also included a significant quantity of 2-epoch J band observations, with an epoch baseline greater than 2 years to calculate proper motions. We present a near infrared proper motion catalogue for the 1500 deg$^2$ of the 2 epoch LAS data, which includes 135,625 stellar sources and a further 88,324 with ambiguous morphological classifications, all with motions detected above the 5$蟽$ level. We developed a custom proper motion pipeline which we describe here. Our catalogue agrees well with the proper motion data supplied for a 300 deg$^2$ subset in the current WFCAM Science Archive (WSA) tenth data release (DR10) catalogue, and in various optical catalogues, but it benefits from a larger matching radius and hence a larger upper proper motion detection limit. We provide absolute proper motions, using LAS galaxies for the relative to absolute correction. By using local 2nd order polynomial transformations, as opposed to linear transformations in the WSA, we correct better for any local distortions in the focal plane, not including the radial distortion that is removed by the UKIDSS pipeline. We present the results of proper motion searches for new brown dwarfs and white dwarfs. We discuss 41 sources in the WSA DR10 overlap with our catalogue with proper motions $>$300 $mas yr^{-1}$, several of which are new detections. We present 15 new candidate ultra-cool dwarf binary systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1311.1227v1-abstract-full').style.display = 'none'; document.getElementById('1311.1227v1-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, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 15 figures, and 8 tables. Public catalogue available at http://star.herts.ac.uk/~lsmith/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1308.0495">arXiv:1308.0495</a> <span> [<a href="https://arxiv.org/pdf/1308.0495">pdf</a>, <a href="https://arxiv.org/ps/1308.0495">ps</a>, <a href="https://arxiv.org/format/1308.0495">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/10.1093/mnras/stt1437">10.1093/mnras/stt1437 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A deep WISE search for very late type objects and the discovery of two halo/thick-disk T dwarfs: WISE 0013+0634 and WISE 0833+0052 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Pinfield%2C+D+J">D. J. Pinfield</a>, <a href="/search/?searchtype=author&query=Gomes%2C+J">J. Gomes</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A+C">A. C. Day-Jones</a>, <a href="/search/?searchtype=author&query=Leggett%2C+S+K">S. K. Leggett</a>, <a href="/search/?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Ruiz%2C+M+T">M. T. Ruiz</a>, <a href="/search/?searchtype=author&query=Kurtev%2C+R">R. Kurtev</a>, <a href="/search/?searchtype=author&query=Cattermole%2C+T">T. Cattermole</a>, <a href="/search/?searchtype=author&query=Cardoso%2C+C">C. Cardoso</a>, <a href="/search/?searchtype=author&query=Lodieu%2C+N">N. Lodieu</a>, <a href="/search/?searchtype=author&query=Faherty%2C+J">J. Faherty</a>, <a href="/search/?searchtype=author&query=Littlefair%2C+S">S. Littlefair</a>, <a href="/search/?searchtype=author&query=Smart%2C+R">R. Smart</a>, <a href="/search/?searchtype=author&query=Irwin%2C+M">M. Irwin</a>, <a href="/search/?searchtype=author&query=Clarke%2C+J+R+A">J. R. A. Clarke</a>, <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P+W">P. W. Lucas</a>, <a href="/search/?searchtype=author&query=Galvez-Ortiz%2C+M+C">M. C. Galvez-Ortiz</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+S">J. S. Jenkins</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Rebolo%2C+R">R. Rebolo</a>, <a href="/search/?searchtype=author&query=Bejar%2C+V+J+S">V. J. S. Bejar</a>, <a href="/search/?searchtype=author&query=Gauza%2C+B">B. Gauza</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="1308.0495v1-abstract-short" style="display: inline;"> A method is defined for identifying late T and Y dwarfs in WISE down to low values of signal-to-noise. This requires a WISE detection only in the W2-band and uses the statistical properties of the WISE multi-frame measurements and profile fit photometry to reject contamination resulting from non-point-like objects, variables and moving sources. To trace our desired parameter space we use a control… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1308.0495v1-abstract-full').style.display = 'inline'; document.getElementById('1308.0495v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1308.0495v1-abstract-full" style="display: none;"> A method is defined for identifying late T and Y dwarfs in WISE down to low values of signal-to-noise. This requires a WISE detection only in the W2-band and uses the statistical properties of the WISE multi-frame measurements and profile fit photometry to reject contamination resulting from non-point-like objects, variables and moving sources. To trace our desired parameter space we use a control sample of isolated non-moving non-variable point sources from the SDSS, and identify a sample of 158 WISE W2-only candidates down to a signal-to-noise limit of 8. For signal-to-noise ranges >10 and 8-10 respectively, ~45% and ~90% of our sample fall outside the selection criteria published by the WISE team (Kirkpatrick et al. 2012), due mainly to the type of constraints placed on the number of individual W2 detections. We present follow-up of eight candidates and identify WISE 0013+0634 and WISE 0833+0052, T8 and T9 dwarfs with high proper motion (~1.3 and ~1.8 arcsec/yr). Both objects show a mid-infrared/near-infrared excess of ~1-1.5 magnitudes, and are K-band suppressed. Distance estimates lead to space motion constraints that suggest halo (or at least thick disk) kinematics. We then assess the reduced proper motion diagram of WISE ultracool dwarfs, which suggests that late T and Y dwarfs may have a higher thick-disk/halo population fraction than earlier objects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1308.0495v1-abstract-full').style.display = 'none'; document.getElementById('1308.0495v1-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 August, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.6333">arXiv:1306.6333</a> <span> [<a href="https://arxiv.org/pdf/1306.6333">pdf</a>, <a href="https://arxiv.org/format/1306.6333">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> Chronos: A NIR spectroscopic galaxy survey. From the formation of galaxies to the peak of activity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Ferreras%2C+I">I. Ferreras</a>, <a href="/search/?searchtype=author&query=Sharples%2C+R">R. Sharples</a>, <a href="/search/?searchtype=author&query=Dunlop%2C+J+S">J. S. Dunlop</a>, <a href="/search/?searchtype=author&query=Pasquali%2C+A">A. Pasquali</a>, <a href="/search/?searchtype=author&query=La+Barbera%2C+F">F. La Barbera</a>, <a href="/search/?searchtype=author&query=Vazdekis%2C+A">A. Vazdekis</a>, <a href="/search/?searchtype=author&query=Khochfar%2C+S">S. Khochfar</a>, <a href="/search/?searchtype=author&query=Cropper%2C+M">M. Cropper</a>, <a href="/search/?searchtype=author&query=Cimatti%2C+A">A. Cimatti</a>, <a href="/search/?searchtype=author&query=Cirasuolo%2C+M">M. Cirasuolo</a>, <a href="/search/?searchtype=author&query=Bower%2C+R">R. Bower</a>, <a href="/search/?searchtype=author&query=Brinchmann%2C+J">J. Brinchmann</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Cappellari%2C+M">M. Cappellari</a>, <a href="/search/?searchtype=author&query=Charlot%2C+S">S. Charlot</a>, <a href="/search/?searchtype=author&query=Conselice%2C+C+J">C. J. Conselice</a>, <a href="/search/?searchtype=author&query=Daddi%2C+E">E. Daddi</a>, <a href="/search/?searchtype=author&query=Grebel%2C+E+K">E. K. Grebel</a>, <a href="/search/?searchtype=author&query=Ivison%2C+R">R. Ivison</a>, <a href="/search/?searchtype=author&query=Jarvis%2C+M+J">M. J. Jarvis</a>, <a href="/search/?searchtype=author&query=Kawata%2C+D">D. Kawata</a>, <a href="/search/?searchtype=author&query=Kennicutt%2C+R+C">R. C. Kennicutt</a>, <a href="/search/?searchtype=author&query=Kitching%2C+T">T. Kitching</a>, <a href="/search/?searchtype=author&query=Lahav%2C+O">O. Lahav</a>, <a href="/search/?searchtype=author&query=Maiolino%2C+R">R. Maiolino</a> , et al. (8 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="1306.6333v1-abstract-short" style="display: inline;"> Chronos is our response to ESA's call for white papers to define the science for the future L2, L3 missions. Chronos targets the formation and evolution of galaxies, by collecting the deepest NIR spectroscopic data, from the formation of the first galaxies at z~10 to the peak of formation activity at z~1-3. The strong emission from the atmospheric background makes this type of survey impossible fr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.6333v1-abstract-full').style.display = 'inline'; document.getElementById('1306.6333v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.6333v1-abstract-full" style="display: none;"> Chronos is our response to ESA's call for white papers to define the science for the future L2, L3 missions. Chronos targets the formation and evolution of galaxies, by collecting the deepest NIR spectroscopic data, from the formation of the first galaxies at z~10 to the peak of formation activity at z~1-3. The strong emission from the atmospheric background makes this type of survey impossible from a ground-based observatory. The spectra of galaxies represent the equivalent of a DNA fingerprint, containing information about the past history of star formation and chemical enrichment. The proposed survey will allow us to dissect the formation process of galaxies including the timescales of quenching triggered by star formation or AGN activity, the effect of environment, the role of infall/outflow processes, or the connection between the galaxies and their underlying dark matter haloes. To provide these data, the mission requires a 2.5m space telescope optimised for a campaign of very deep NIR spectroscopy. A combination of a high multiplex and very long integration times will result in the deepest, largest, high-quality spectroscopic dataset of galaxies from z=1 to 12, spanning the history of the Universe, from 400 million to 6 billion years after the big bang, i.e. covering the most active half of cosmic history. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.6333v1-abstract-full').style.display = 'none'; document.getElementById('1306.6333v1-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 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </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">White paper for the science definition of ESA's future L2,L3 missions. Updates will be found here: http://www.chronos-mission.eu</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.4527">arXiv:1306.4527</a> <span> [<a href="https://arxiv.org/pdf/1306.4527">pdf</a>, <a href="https://arxiv.org/ps/1306.4527">ps</a>, <a href="https://arxiv.org/format/1306.4527">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stt876">10.1093/mnras/stt876 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> NPARSEC: NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Smart%2C+R+L">R. L. Smart</a>, <a href="/search/?searchtype=author&query=Tinney%2C+C+G">C. G. Tinney</a>, <a href="/search/?searchtype=author&query=Bucciarelli%2C+B">B. Bucciarelli</a>, <a href="/search/?searchtype=author&query=Marocco%2C+F">F. Marocco</a>, <a href="/search/?searchtype=author&query=Abbas%2C+U">U. Abbas</a>, <a href="/search/?searchtype=author&query=Andrei%2C+A">A. Andrei</a>, <a href="/search/?searchtype=author&query=Bernardi%2C+G">G. Bernardi</a>, <a href="/search/?searchtype=author&query=Burningham%2C+B">B. Burningham</a>, <a href="/search/?searchtype=author&query=Cardoso%2C+C">C. Cardoso</a>, <a href="/search/?searchtype=author&query=Costa%2C+E">E. Costa</a>, <a href="/search/?searchtype=author&query=Crosta%2C+M+T">M. T. Crosta</a>, <a href="/search/?searchtype=author&query=Dapra%2C+M">M. Dapra</a>, <a href="/search/?searchtype=author&query=Day-Jones%2C+A">A. Day-Jones</a>, <a href="/search/?searchtype=author&query=Goldman%2C+B">B. Goldman</a>, <a href="/search/?searchtype=author&query=Jones%2C+H+R+A">H. R. A. Jones</a>, <a href="/search/?searchtype=author&query=Lattanzi%2C+M+G">M. G. Lattanzi</a>, <a href="/search/?searchtype=author&query=Leggett%2C+S+K">S. K. Leggett</a>, <a href="/search/?searchtype=author&query=Lucas%2C+P">P. Lucas</a>, <a href="/search/?searchtype=author&query=Mendez%2C+R">R. Mendez</a>, <a href="/search/?searchtype=author&query=Penna%2C+J+L">J. L. Penna</a>, <a href="/search/?searchtype=author&query=Pinfield%2C+D">D. Pinfield</a>, <a href="/search/?searchtype=author&query=Smith%2C+L">L. Smith</a>, <a href="/search/?searchtype=author&query=Sozzetti%2C+A">A. Sozzetti</a>, <a href="/search/?searchtype=author&query=Vecchiato%2C+A">A. Vecchiato</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="1306.4527v1-abstract-short" style="display: inline;"> The discovery and subsequent detailed study of T dwarfs has provided many surprises and pushed the physics and modeling of cool atmospheres in unpredicted directions. Distance is a critical parameter for studies of these objects to determine intrinsic luminosities, test binarity and measure their motion in the Galaxy. We describe a new observational program to determine distances across the full r… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.4527v1-abstract-full').style.display = 'inline'; document.getElementById('1306.4527v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.4527v1-abstract-full" style="display: none;"> The discovery and subsequent detailed study of T dwarfs has provided many surprises and pushed the physics and modeling of cool atmospheres in unpredicted directions. Distance is a critical parameter for studies of these objects to determine intrinsic luminosities, test binarity and measure their motion in the Galaxy. We describe a new observational program to determine distances across the full range of T dwarf sub-types using the NTT/SOFI telescope/instrument combination. We present preliminary results for ten objects, five of which represent new distances. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.4527v1-abstract-full').style.display = 'none'; document.getElementById('1306.4527v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </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, 6 figrues, accepted by MNRAS</span> </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=Burningham%2C+B&start=50" 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