Meeting the cool neighbors. X. Ultracool dwarfs from the 2MASS All-Sky data reslease
Abstract
Using data from the 2 Micron All Sky Survey All-Sky Point Source Catalogue, we have extended our census of nearby ultracool dwarfs to cover the full celestial sphere above Galactic latitude of 15°. Starting with an initial catalog of 2,139,484 sources, we have winnowed the sample to 467 candidate late-type M or L dwarfs within 20 pc of the Sun. Fifty-four of those sources already have spectroscopic observations confirming them as late-type dwarfs. We present optical spectroscopy of 376 of the remaining 413 sources, and identify 44 as ultracool dwarfs with spectroscopic distances less than 20 pc. Twenty-five of the 37 sources that lack optical data have near-infrared spectroscopy. Combining the present sample with our previous results and data from the literature, we catalog 94 L dwarf systems within 20 pc. We discuss the distribution of activity, as measured by Hα emission, in this volume-limited sample. We have coupled the present ultracool catalog with data for stars in the northern 8 pc sample and recent (incomplete) statistics for T dwarfs to provide a snapshot of the current 20 pc census as a function of spectral type.
Additional Information
© 2008 The American Astronomical Society. Received 2008 April 15, accepted for publication 2008 June 14. Published 2008 August 15. Print publication: Issue 3 (2008 September). The NStars research described in this paper was partially supported by a grant awarded as part of the NASA Space Interferometry Mission Science Program, administered by the Jet Propulsion Laboratory, Pasadena. Support for K.L.C. is provided by NASA through the Spitzer Space Telescope Fellowship Program, through a contract issued by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. P.R.A. acknowledges support from grant NAG5-11627 to Kevin Luhman from the NASA Long-Term Space Astrophysics program. This publication makes use of data products from the Two Micron All Sky Survey (2MASS), which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by NASA and the National Science Foundation. We acknowledge use of the NASA/IPAC Infrared Source Archive (IRSA), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. We also acknowledge making extensive use of the SIMBAD database, maintained by Strasbourg Observatory, and of the ADS bibliographic service. This research has made extensive use of the M-, L-, and T-dwarf compendium housed at DwarfArchives.org and maintained by Chris Gelino, Davy Kirkpatrick, and Adam Burgasser. This program has also profited from extensive allocations of telescope time at both Kitt Peak Observatory and Cerro Tololo Inter-American Observatory (CTIO). We thank the National Optical Astronomy Observatory (NOAO) Telescope Allocation Committees for their support of this project and acknowledge the courteous and efficient assistance of the technical support staff: John Glaspey, Darryl Willmarth, Diane Harmer, Bill Gillespie, Hillary Mathis, and Hal Halbedel at KPNO, and Alberto Alvarez, Angel Guerra, and Patricio Ugarte at CTIO. [I.N.R., K.L.C., J.D.K., P.R.A., F.M., J.L., and P.L. were] Visiting Astronomer[s], Kitt Peak National Observatory, NOAO, which is operated by the Association of Universities for Research in Astronomy, Inc. under cooperative agreement with the NSF. [K.L.C. was a] Spitzer Fellow. Online-only material: machine-readable and VO tables. An erratum for this article has been published in 2008 The Astronomical Journal 136 2222.Attached Files
Published - REIaj08b.pdf
Erratum - REIaj08bcorr.pdf
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Additional details
- Eprint ID
- 12020
- Resolver ID
- CaltechAUTHORS:REIaj08b
- NAG5-11627
- NASA
- NSF
- NASA/JPL/Caltech
- NASA Spitzer Fellowship
- Created
-
2008-10-20Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)