The Spectra of T Dwarfs. I. Near‐Infrared Data and Spectral Classification

Burgasser, Adam J.; Kirkpatrick, J. Davy; Brown, Michael E.; Reid, I. Neill; Burrows, Adam; Liebert, James; Matthews, K.; Gizis, John E.; Dahn, C. C.; Monet, D. G.; Cutri, R. M.; Skrutskie, Michael F.

doi:10.1086/324033

Cited by 416 publications

(548 citation statements)

References 81 publications

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“…The OMEGA-CASS photometry confirms our conclusion that the companion is a late T dwarf. Its photometry is fully consistent with late T dwarfs like Gl 570 D (Burgasser et al 2000) or 2MASSJ0415 (Burgasser et al 2002). Our spectral type estimate was most recently confirmed by Luhman et al (2006) and Burgasser (2006).…”

Section: The Hd 3651 Ab Systemsupporting

confidence: 87%

Multiplicity Study of Exoplanet Host Stars: the HD 3651 AB System

et al. 2006

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Section: The Hd 3651 Ab Systemsupporting

confidence: 87%

Multiplicity Study of Exoplanet Host Stars: the HD 3651 AB System

et al. 2006

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“…CH 4 bands are expected and have been observed in T dwarfs (Burgasser et al 2002a) but, in the spectral range considered here, are much weaker than the water vapor lines and so cannot be identified with confidence.…”

Section: Modelled and Observed Spectramentioning

confidence: 56%

Physical parameters of T dwarfs derived from high-resolution near-infrared spectra

Burgo

Martín

Osorio

et al. 2009

A&A

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Aims. We determine the effective temperature, surface gravity and projected rotational velocity of nine T dwarfs from the comparison of high-resolution near-infrared spectra and synthetic models, and estimate the mass and age of the objects from state-of-the-art models. Methods. We use the AMES-COND cloudless solar metallicity models provided by the PHOENIX code to match the spectra of nine T-type field dwarfs observed with the near-infrared high-resolution spectrograph NIRSPEC using ten echelle orders to cover part of the J band from 1.147 to 1.347 μm with a resolving power R ∼ 20 000. The projected rotational velocity, effective temperature and surface gravity of the objects are determined based on the minimum root mean square of the differences between the modelled and observed relative fluxes. Estimates of the mass and age of the objects are obtained from effective temperature-surface gravity diagrams, where our results are compared with existing solar metallicity models. Results. The modelled spectra reproduce quite well the observed features for most of the T dwarfs, with effective temperatures in the range of 922-1009 K, and surface gravities between 10 4.1 and 10 4.9 cm s −2 . Our results support the assumption of a dust free atmosphere for T dwarfs later than T5, where dust grains form and then gravitationally sediment into the low atmosphere. The modelled spectra do not accurately mimic some individual very strong lines like the K i doublet at 1.2436 and 1.2525 μm. Our modelled spectra does not match well the observed spectra of the two T dwarfs with earlier spectral types, namely SDSSp J125453.90-012247.4 (T2) and 2MASS J05591914-1404488 (T4.5), which is likely due to the presence of condensate clouds that are not incorporated in the models used here. By comparing our results and their uncertainties to evolutionary models, we estimate masses in the interval ≈5−75 M J for T dwarfs later than T5, which are in good agreement with those found in the literature. We found apparent young ages that are typically between 0.1 and a few Gyr for the same T dwarfs, which is consistent with recent kinematical studies.

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“…Samples of Ldwarfs have revealed a surprising diversity of near-IR colors (e.g., Leggett et al 2002;Knapp et al 2004;Gizis et al 2012), which are believed to be caused by variations in surface gravity and/or dusty clouds (e.g., Kirkpatrick et al 2008; or thermochemical instabilities (Tremblin et al 2016). Objects transitioning from L to T spectral types undergo a dramatic shift to bluer near-IR colors, thought to be driven by the clearing of clouds and the formation of methane (e.g., Burgasser et al 2002;Chiu et al 2006;Saumon & Marley 2008). UKIDSS and WISEhave illustrated the diversity of late-T and Y dwarf near-and mid-IR colors (e.g., Burningham et al 2010b;Kirkpatrick et al 2011;Mace et al 2013), and WISEhas enabled the discovery of the coolest known substellar objects (e.g., Cushing et al 2011;Kirkpatrick et al 2012;.…”

Section: Introductionmentioning

confidence: 99%

Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3 π Survey

Best

Magnier

Liu

et al. 2017

ApJS

118

110

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractWe present a catalog of 9888 M, L and T dwarfs detected in the Pan-STARRS13π Survey (PS1), covering threequarters of the sky. Our catalog contains nearly all known objects of spectral types L0-T2 in the PS1 field, with objects as early as M0 and as late as T9, and includes PS1, 2MASS, AllWISE, and GaiaDR1 photometry. We analyze the different types of photometry reported by PS1 and use two types in our catalog in order to maximize both depth and accuracy. Using parallaxes from the literature, we construct empirical SEDs for field ultracool dwarfs spanning 0.5-12 μm. We determine typical colors of M0-T9 dwarfs and highlight the distinctive colors of subdwarfs and young objects. We combine astrometry from PS1, 2MASS, and GaiaDR1 to calculate new proper motions for our catalog. We achieve a median precision of 2.9mas yr −1 , a factor of ≈3−10 improvement over previous large catalogs. Our catalog contains proper motions for 2405M6-T9 dwarfs and includes the largest set of homogeneous proper motions for L and T dwarfs published to date, 406objects for which there were no previous measurements, and 1176objects for which we improve upon previous literature values. We analyze the kinematics of ultracool dwarfs in our catalog and find evidence that bluer but otherwise generic late-M and Lfield dwarfs (i.e., not subdwarfs) tend to have tangential velocities higher than those of typical field objects. With the public release of the PS1 data, this survey will continue to be an essential tool for characterizing the ultracool dwarf population.

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The Spectra of T Dwarfs. I. Near‐Infrared Data and Spectral Classification

Cited by 416 publications

References 81 publications

Multiplicity Study of Exoplanet Host Stars: the HD 3651 AB System

Multiplicity Study of Exoplanet Host Stars: the HD 3651 AB System

Physical parameters of T dwarfs derived from high-resolution near-infrared spectra

Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3 π Survey

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