Discovery of Three Distant, Cold Brown Dwarfs in the WFC3 Infrared Spectroscopic Parallels Survey
Abstract
We present the discovery of three late-type (≥T4.5) brown dwarfs, including a probable Y dwarf, in the WFC3 Infrared Spectroscopic Parallels (WISP) survey. We use the G141 grism spectra to determine the spectral types of the dwarfs and derive distance estimates based on a comparison with nearby T dwarfs with known parallaxes. These are the most distant spectroscopically confirmed T/Y dwarfs, with the farthest at an estimated distance of ∼400 pc. We compare the number of cold dwarfs found in the WISP survey with simulations of the brown dwarf mass function. The number found is generally consistent with an initial stellar mass function dN/dM ∝ M^(−α) with α = 0.0–0.5, although the identification of a Y dwarf is somewhat surprising and may be indicative of either a flatter absolute magnitude/spectral-type relation than previously reported or an upturn in the number of very-late-type brown dwarfs in the observed volume.
Additional Information
© 2012 The American Astronomical Society. All rights reserved. Received 2012 April 10; accepted 2012 April 26; published 2012 May 25. We thank an anonymous referee for helpful comments that improved this Letter. This research has benefitted from the SpeX Prism Spectral Libraries, maintained by Adam Burgasser at http://www.browndwarfs.org/spexprism. We also thank Michael Cushing for providing Y0 spectra from the WISE survey. This work has been supported by the Carnegie Observatories Graduate Research Fellowship.Attached Files
Published - Masters2012p18611Astrophys_J_Lett.pdf
Submitted - 1204.6320v1.pdf
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Additional details
- Eprint ID
- 32079
- Resolver ID
- CaltechAUTHORS:20120626-085631497
- Carnegie Observatories Graduate Research Fellowship
- Created
-
2012-06-26Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)