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Determining the Physical Properties of Very-Low-Mass Stars and Brown Dwarfs in the Near-Infrared

Rice, Emily L. and Barman, Travis S. and McLean, Ian S. and Prato, L. and Kirkpatrick, J. Davy (2009) Determining the Physical Properties of Very-Low-Mass Stars and Brown Dwarfs in the Near-Infrared. In: Cool Stars, Stellar Systems and the Sun. AIP Conference Proceedings. No.1094. American Institute of Physics , Melville, NY, pp. 178-183. ISBN 978-0-7354-0627-8.

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Accurate measurements of the fundamental physical properties of very‐low‐mass stars and brown dwarfs are crucial for calibrating evolutionary models. Photometry and low‐resolution spectroscopy effectively average over absorption features that sample different layers in complex cool atmospheres. By studying a large sample of objects bright enough for high‐resolution spectroscopy, we can develop methods for determining physical properties as accurately and efficiently as possible. As part of the Brown Dwarf Spectroscopic Survey (BDSS; [1, 2]), we are conducting a detailed comparison of observed and synthetic spectra for a sample of young M and L dwarfs and field M, L, and T dwarfs ( ∼50 objects in total). High‐resolution near‐infrared spectra from NIRSPEC on Keck II provide an unequaled combination of resolving power and wavelength coverage. Synthetic spectra were created from PHOENIX atmosphere models calculated exclusively for this project with updated line lists and solar abundances. Combined with spectral types from photometric studies and low‐resolution spectra and surface gravity estimates from age determination, the high‐resolution spectra enable precise measurements of effective temperature and surface gravity, as well as accurate determination of radial velocity and projected rotational velocity. Our preliminary observation‐model comparisons distinguish between wavelength regimes for which the models reproduce observed high‐resolution spectra and regimes in which model data (line lists, oscillator strengths, etc.) are lacking.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Rice, Emily L.0000-0002-3252-5886
Barman, Travis S.0000-0002-7129-3002
Kirkpatrick, J. Davy0000-0003-4269-260X
Additional Information:© 2009 American Institute of Physics. Published online 16 February 2009. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:Stars: low-mass, brown dwarfs, Stars: atmospheres, Infrared: stars, Techniques: spectroscopic
Series Name:AIP Conference Proceedings
Issue or Number:1094
Classification Code:PACS: 95.30.Ky, 95.75.Fg, 95.85.Jq,97.10.Ex, 97.20.Vs
Record Number:CaltechAUTHORS:20160505-083412845
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:66674
Deposited By: Ruth Sustaita
Deposited On:06 May 2016 19:03
Last Modified:14 Oct 2019 22:01

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