DISCOVERY OF THREE DISTANT, COLD BROWN DWARFS IN THE WFC3 INFRARED SPECTROSCOPIC PARALLELS SURVEY

Journal Article · Sun Jun 10 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/752/1/L14· OSTI ID:22047758

Masters, D; Siana, B ^[1]; McCarthy, P; Hathi, N P; Dressler, A ^[2]; Burgasser, A J ^[3]; Malkan, M; Ross, N R ^[4]; Scarlata, C ^[5]; Henry, A ^[6]; Colbert, J; Atek, H ^[7]; Rafelski, M; Teplitz, H ^[8]; Bunker, A ^[9]

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1. Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)
2. Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)
3. Center for Astrophysics and Space Science, University of California, San Diego, La Jolla, CA 92093 (United States)
4. Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States)
5. Astronomy Department, University of Minnesota, Minneapolis, MN 55455 (United States)
6. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
7. Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States)
8. Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States)
9. Department of Physics, University of Oxford, Oxford (United Kingdom)

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 {approx}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{proportional_to}M{sup -{alpha}} with {alpha} = 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.

• OSTI ID: 22047758
• Journal Information: Astrophysical Journal Letters, Vol. 752, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTRONOMY
ASTROPHYSICS
COMPARATIVE EVALUATIONS
DISTANCE
DWARF STARS
GALAXIES
INFRARED SPECTRA
INFRARED SURVEYS
LUMINOSITY
MASS