J/ApJ/940/164ivo://CDS.VizieR/J/ApJ/940/164doi:10.26093/cds/vizier.19400164CDSCalamari E.Faherty J.K.Burningham B.Gonzales E.,Bardalez-Gagliuffi D.Vos J.M.Gemma M.Whiteford N.Gaarn J.2025-02-24T20:13:33Z2024-12-04T13:01:34ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frbrown-dwarfsmultiple-starst-dwarfsspectral-energy-distributioninfrared-astronomyspectroscopyvisible-astronomyastronomical-modelsWe 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+ 2015ApJ...807..183L & 2017ApJ...848...83L; Zalesky+ 2022ApJ...936...44Z and Gonzales+ 2020ApJ...905...46G. Fundamental parameters (mass, radius, log(L_Bol_/L_Sun_), log(g)) determined from our model agree within 1{sigma} to SED-derived values, except for Teff where our retrieved Teff is approximately 100K cooler than the evolutionary model-based SED value. We find a retrieved mass of 50_-9_^+12^M_Jup_, however, we also find that the observables of Gl229B can be explained by a cloud-free model with a prior on mass at the dynamical value, 70M_Jup_. We are able to constrain abundances for H_2_O, 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 and internal physical processes, as well as model biases.2022ApJ...940..164Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/940/164CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/327/1039 : Structure and evolution of low-mass stars (Chabrier+ 1997)J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)J/ApJ/637/1067 : NIR spectral classification of T dwarfs (Burgasser+, 2006)J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)J/A+A/510/A99 : Epsilon Indi Ba and Bb IR spectra (King+, 2010)J/MNRAS/433/457 : 76 T dwarfs from the UKIDSS LAS (Burningham+, 2013)J/ApJS/214/25 : Rosseland & Planck gaseous mean opacities (Freedman+, 2014)J/ApJ/791/54 : Nearby M Dwarfs parameters (Gaidos+, 2014)J/A+A/564/A55 : 1.1-2.4um spectra of 7 young M & L dwarfs (Manjavacas+, 2014)J/ApJS/216/7 : Planets Around Low-Mass Stars (PALMS). IV. (Bowler+, 2015)J/ApJ/810/158 : M,L,T dwarfs fundamental param. and SEDs (Filippazzo+, 2015)J/ApJ/889/176 : Very low-mass binaries with Gaia DR2 data (Faherty+, 2020)J/ApJ/923/48 : Discovery of an L dwarf co-moving BD+60 1417 (Faherty+, 2021)J/AJ/162/290 : OSIRIS K-band sp. of planets HR8799 b, c & d (Ruffio+, 2021)J/AJ/163/288 : Absolute & relative astrometry for eps Indi B (Chen+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/940/164https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/940/164http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/940/164https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/940/164https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/940/164http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/940/164GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/940/164/fig1*Distanced-calibrated SED for Gl 229BrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[0.6/5.1] Wavelength (1)umem.wldoubleFlux[4.6e-21/4.4e-16] Flux; erg/s/cm^2^/{AA} (2)cW.m**-2.nm**-1phot.fluxdoublee_Flux[2.3e-22/2.2e-17] Uncertainty in FluxcW.m**-2.nm**-1stat.error;phot.fluxdoubleJ/ApJ/940/164/fig3The temperature-pressure profilelogP[-4/2.3] log pressurebarphys.pressurefloatTemp[248/2050] TemperatureKphys.temperaturedoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ/ApJ/940/164/fig4The median and maximum likelihood retrieved spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintModelModel type (1)meta.id;stat.fitcharlambda[1.0005/5.005] Wavelengthumem.wldoubleFlux[4.17e-18/4.1e-15] FluxW.m**-2.um**-1phot.flux;meta.modelleddoublee_Flux? Lower uncertainty in Flux (2)W.m**-2.um**-1stat.error;phot.flux;meta.modelleddoublenullableE_Flux? Upper uncertainty in Flux (2)W.m**-2.um**-1stat.error;phot.flux;meta.modelleddoublenullable