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We report the spectroscopic identification of three brown dwarf candidates -- o005_s41280, o006_s00089, and o006_s35616 -- discovered in the RUBIES using James Webb Space Telescope (JWST) Near-Infrared Spectrograph (NIRSpec) PRISM/CLEAR…

Solar and Stellar Astrophysics · Physics 2025-01-29 Zhijun Tu , Shu Wang , Xiaodian Chen , Jifeng Liu

Recent studies have shown that galaxies at cosmic noon are redder in the center and bluer in the outskirts, mirroring results in the local universe. These color gradients could be caused by either gradients in the stellar age or dust…

The atmospheres of brown dwarfs orbiting in close proximity to their parent white dwarf represent some of the most extreme irradiated environments known. Understanding their complex dynamical mechanisms pushes the limits of theoretical and…

Solar and Stellar Astrophysics · Physics 2022-03-21 Elspeth K. H. Lee , Joshua D. Lothringer , Sarah L. Casewell , Daniel Kitzmann , Ben W. P. Lew , Yifan Zhou

We post-process galaxies in the IllustrisTNG simulations with SKIRT radiative transfer calculations to make predictions for the rest-frame near-infrared (NIR) and far-infrared (FIR) properties of galaxies at $z\geq 4$. The rest-frame $K$-…

Context: Low-mass stars and extrasolar planets have ultra-cool atmospheres where a rich chemistry occurs and clouds form. The increasing amount of spectroscopic observations for extrasolar planets requires self-consistent model atmosphere…

Solar and Stellar Astrophysics · Physics 2017-12-13 Diana Juncher , Uffe G. Jørgensen , Christiane Helling

We present the results of an intense photometric monitoring in the near-infrared (~0.9 microns) with the TRAPPIST robotic telescope of the newly discovered binary brown dwarf WISE J104915.57-531906.1, the third closest system to the Sun at…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. Gillon , A. H. M. J. Triaud , E. Jehin , L. Delrez , C. Opitom , P. Magain , M. Lendl , D. Queloz

Low mass (sub)stellar objects represent the low end of the initial mass function, the transition to free-floating planets and a prominent interloper population in the search for high-redshift galaxies. Without proper motions or…

We fit a sample of 49 R=6000 NIR (0.9 - 2.5 micron) T dwarf spectra obtained with Magellan's FIRE spectrograph with two different atmospheric model sets to compare the derived physical parameters such as Teff, log g, cloud opacity, and…

Solar and Stellar Astrophysics · Physics 2013-08-27 C. P. Nicholls , A. J. Burgasser , C. V. Morley

We report the discovery of a young planetary-mass brown dwarf in the rho Oph cloud core. The object was identified as such with the aid of a 1.5-2.4 micron low-resolution spectrum obtained using the NIRC instrument on the Keck I telescope.…

Solar and Stellar Astrophysics · Physics 2015-05-14 Kenneth A. Marsh , J. Davy Kirkpatrick , Peter Plavchan

We present JWST NIRSpec/G395H transmission spectroscopy observations of GJ 357 b, a warm ($T_{\mathrm{eq}} \approx 525$ K) super-Earth ($1.2\ \mathrm{R_{\oplus}} $, $1.84\ \mathrm{M_{\oplus}} $) orbiting a nearby M3-type star, with a median…

We present model atmospheres for an Earth-like planet orbiting the entire grid of main sequence FGK stars with effective temperatures ranging from Teff = 4250K to Teff = 7000K in 250K intervals. We model the remotely detectable spectra of…

Earth and Planetary Astrophysics · Physics 2013-04-11 Sarah Rugheimer , Lisa Kaltenegger , Andras Zsom , Antígona Segura , Dimitar Sasselov

The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have concluded that the…

Earth and Planetary Astrophysics · Physics 2015-06-05 Mark S. Marley , Didier Saumon , Michael Cushing , Andrew S. Ackerman , Jonathan J. Fortney , Richard Freedman

Protostellar systems, ranging from low-luminosity T Tauri and Herbig Ae stars to high-luminosity Herbig Be stars, exhibit a near-infrared (NIR) excess in their spectra that is dominated by a bump in the monochromatic luminosity with a peak…

Solar and Stellar Astrophysics · Physics 2015-06-05 Alissa Bans , Arieh Konigl

The origin of the very red optical and infrared colours of intermediate-age ($\sim$10 - 500 Myr) L-type dwarfs remains unknown. It has been suggested that low-gravity atmospheres containing large amounts of dust may account for the observed…

Earth and Planetary Astrophysics · Physics 2016-09-21 Olga V. Zakhozhay , María Rosa Zapatero Osorio , Víctor J. S. Béjar , Yann Boehler

We investigate the potential for the James Webb Space Telescope (JWST) to detect and characterize the atmospheres of the sub-Neptunian exoplanets in the TOI-270 system. Sub-Neptunes are considered more likely to be water worlds than gas…

Earth and Planetary Astrophysics · Physics 2020-05-13 J. Chouqar , Z. Benkhaldoun , A. Jabiri , J. Lustig-Yaeger , A. Soubkiou , A. Szentgyorgyi

We present a distant T$-$type brown dwarf candidate at $\approx2.55$ kpc discovered in the Cosmic Evolution Early Release Science (CEERS) fields by James Webb Space Telescope (JWST) NIRCam. In addition to the superb sensitivity, we utilised…

The James Webb Space Telescope (JWST) is now observing Y dwarfs, the coldest known brown dwarfs, with effective temperatures T_eff <= 475 K. The first published observations provide important information: not only is the atmospheric…

Solar and Stellar Astrophysics · Physics 2023-09-27 S. K. Leggett , Pascal Tremblin

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…

Observationally, spectra of brown dwarfs indicate the presence of dust in their atmospheres while theoretically it is not clear what prevents the dust from settling and disappearing from the regions of spectrum formation. Consequently,…

Solar and Stellar Astrophysics · Physics 2015-05-18 Bernd Freytag , France Allard , Hans-Guenter Ludwig , Derek Homeier , Matthias Steffen

We construct models for strongly-magnetized neutron star atmospheres composed of mid-Z elements (carbon, oxygen and neon) with magnetic fields B=10^{12}-10^{13} G and effective temperatures Teff=(1-5)*10^6 K; this is done by first…

Astrophysics · Physics 2008-11-26 Kaya Mori , Wynn C. G. Ho
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