The NIRSPEC Brown Dwarf Spectroscopic Survey. I. Low-Resolution Near-Infrared Spectra
Abstract
We present the first results of a near-infrared (0.96-2.31 micron) spectroscopic survey of M, L, and T dwarfs obtained with NIRSPEC on the Keck II telescope. Our new survey has a resolving power of R = 2000 and is comprised of two major data sets: 53 J-band (1.14-1.36 micron) spectra covering all spectral types from M6 to T8 with at least two members in each spectral subclass (wherever possible), and 25 flux-calibrated spectra from 1.14 to 2.31 microns for most spectral classes between M6 and T8. Sixteen of these 25 objects have additional spectral coverage from 0.96-1.14 microns to provide overlap with optical spectra. Spectral flux ratio indexes for prominent molecular bands are derived and equivalent widths (EWs) for several atomic lines are measured. We find that a combination of four H2O and two CH4 band strengths can be used for spectral classification. Weak (EW~1-2 angstrom) atomic lines of Al I and Ca I disappear at the boundary between M and L types.
Keywords
Cite
@article{arxiv.astro-ph/0309257,
title = {The NIRSPEC Brown Dwarf Spectroscopic Survey. I. Low-Resolution Near-Infrared Spectra},
author = {Ian S. McLean and Mark R. McGovern and Adam J. Burgasser and J. Davy Kirkpatrick and L. Prato and Sungsoo S. Kim},
journal= {arXiv preprint arXiv:astro-ph/0309257},
year = {2010}
}
Comments
60 pages, 25 figures. To appear in the Astrophysical Journal Vol 596. Received 2003 March 31; accepted 2003 June 20. Web site at http://www.astro.ucla.edu/~mclean/BDSSarchive