SDSS J125637-022452: a high proper motion L subdwarf

Abstract

We report the discovery of a high proper motion L subdwarf ($\mu$ =0.617arcsec/yr) in the Sloan Digital Sky Survey spectral database. The optical spectrum from the star SDSS J125637-022452 has mixed spectral features of both late-M spectral subtype (strong TiO and CaH at 7000A) and mid-L spectral subtype (strong wings of KI at 7700A, CrH and FeH), which is interpreted as the signature of a very low-mass, metal-poor star (ultra-cool subdwarf) of spectral type sdL. The near infrared (NIR) (J-Ks) colors from 2MASS shows the object to be significantly bluer compared to normal L dwarfs, which is probably due a strong collision induced absorption (CIA) due to H2 molecule. This is consistent with the idea that CIA from H2 is more pronounced at low metallicities. Proper motion and radial velocity measurements also indicate that the star is kinematically "hot" and probably associated with the Galactic halo population.

13 pages, 2 figures. Accepted for ApJL

References in corpus (25)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• The Theory of Brown Dwarfs and Extrasolar Giant Planets
• Kinematics of Metal-Poor Stars in the Galaxy. III. Formation of the Stellar Halo and Thick Disk as Revealed from a Large Sample of Non-Kinematically Selected Stars
• Astrometry and Photometry for Cool Dwarfs and Brown Dwarfs
• Sixty-seven Additional L Dwarfs Discovered by the Two Micron All Sky Survey (2MASS)
• Towards Spectral Classification of L and T Dwarfs: Infrared and Optical Spectroscopy and Analysis
• Characterization of M,L and T dwarfs in the Sloan Digital Sky Survey
• M-Subdwarfs: Spectroscopic Classification and the Metallicity Scale
• Spectroscopic Properties of Cool Stars in the SDSS: An Analysis of Magnetic Activity and a Search for Subdwarfs
• Revised metallicity classes for low-mass stars: dwarfs (dM), subdwarfs (sdM), extreme subdwarfs (esdM), and ultra subdwarfs (usdM)
• The First Substellar Subdwarf? Discovery of a Metal-poor L Dwarf with Halo Kinematics
• The Spectra of T Dwarfs. II. Red Optical Data
• New High Proper Motion Stars from the Digitized Sky Survey. I. Northern Stars with proper motion between 0.5 and 2.0 arcsec/yr at Low Galactic Latitudes
• Optical Spectroscopy of 2MASS Color-Selected Ultracool Subdwarfs
• Discovery of a Second L Subdwarf in the Two Micron All Sky Survey
• LSR1610-0040: the first early-type L subdwarf
• Twenty-three new ultra-cool subdwarfs from the Sloan Digital Sky Survey
• Trigonometric parallaxes of ten ultracool subdwarfs
• New High Proper Motion Stars from the Digitized Sky Survey. II. Northern Stars with 0.5<mu<2.0 arcsec/yr at High Galactic Latitudes
• The First High-Resolution Spectra of 1.3 L Subdwarfs
• Trigonometric Parallaxes for Two Late-Type Subdwarfs: LSR1425+71 (sdM8.0) and the Binary LSR1610-00 (sd?M6pec)
• The Schizophrenic Spectrum of LSR 1610-0040: a Peculiar M Dwarf/Subdwarf
• Halo Stars Near the Hydrogen-Burning Limit: The M/L Subdwarf Transition

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