Characterization of M, L, and T Dwarfs in the Sloan Digital Sky Survey

摘要: An extensive sample of M, L, and T dwarfs identified in the Sloan Digital Sky Survey (SDSS) has been compiled. The 718 includes 677 new objects (629 M 48 L dwarfs), together with 41 that have previously published. All some published ones optical spectra obtained either SDSS spectrographs or Apache Point Observatory 3.5 m ARC telescope. Spectral types colors are available for all objects; approximately 35% also near-infrared magnitudes measured by 2MASS (Two Micron Survey) on Mauna Kea system. We use this to characterize color–spectral type color-color relations late-type filters derive spectroscopic photometric parallax future studies luminosity mass functions based data. find i* - z* J provide good spectral absolute magnitude (Mi*) estimates dwarfs. Our distance current indicate is finding early out ~1.5 kpc, ~100 pc, ~20 pc. dwarf data show large scatter therefore less reliable estimation.