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M.R. McGovern, I.S. McLean, L. Prato, A.J. Burgasser (UCLA), J.D. Kirkpatrick (IPAC)
The major goal of the NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS - McLean et al. 2000, ApJ, 533, L45) is to obtain a complete sample of low resolution (R~ 2000) spectra spanning the M, L, and T dwarf sub-classes in order to extend spectral classification schemes to near-infrared wavebands and to investigate the spectral signatures of temperature, gravity, and composition by comparison to theoretical models. Additional goals include the acquisition of higher resolution spectra (R~ 25,000) of a sub-sample of the survey for detailed comparison with models and to search for radial velocity variations. The initial phase of the survey is complete with the acquisition of low resolution J-band spectra for two objects per sub-class spanning the range M6 to T8, with one object every other sub-class, in the same range, observed from 0.9-2.35 microns to produce a complete, flux-calibrated spectrum overlapping with previously obtained Keck LRIS data from 0.5-1.0 microns. Several of the brighter sources have also been observed at high resolution at J-band. To date, over 70 objects have been studied including 17 M dwarfs, 36 L dwarfs and 18 T dwarfs. Results from the initial phase of the survey are presented along with some preliminary results from our next directed phase study into the investigation of gravity signatures in these low-mass objects based upon infrared spectral features.
The author(s) of this abstract have provided an email address for comments about the abstract: mcgovern@astro.ucla.edu
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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.