2MASS J06164006-6407194: The First Outer Halo L Subdwarf
| Autor: | Cushing, M. C., Looper, D., Burgasser, A. J., Kirkpatrick, J. D., Faherty, J., Cruz, K., Sweet, A., Sanderson, R. E. |
|---|---|
| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Astrophys.J.696:986-993,2009 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/696/1/986 |
| Popis: | We present the serendipitous discovery of an L subdwarf, 2MASS J06164006-6407194, in a search of the Two Micron All Sky Survey for T dwarfs. Its spectrum exhibits features indicative of both a cool and metal poor atmosphere including a heavily pressured-broadened K I resonant doublet, Cs I and Rb I lines, molecular bands of CaH, TiO, CrH, FeH, and H2O, and enhanced collision induced absorption of H2. We assign 2MASS 0616-6407 a spectral type of sdL5 based on a comparison of its red optical spectrum to that of near solar-metallicity L dwarfs. Its high proper motion (mu =1.405+-0.008 arcsec yr-1), large radial velocity (Vrad = 454+-15 km s-1), estimated uvw velocities (94, -573, 125) km s-1 and Galactic orbit with an apogalacticon at ~29 kpc are indicative of membership in the outer halo making 2MASS 0616-6407 the first ultracool member of this population. Comment: Accepted for publication in ApJ |
| Databáze: | arXiv |
| Externí odkaz: |
|