We report on new measurements of the luminosity function (LF) and mass function (MF) of field low-mass dwarfs derived from Sloan Digital Sky Survey Data Release 6 photometry. The analysis incorporates ~15 million low-mass stars (0.1 ), spread over 8400 deg2. Stellar distances are estimated using new photometric parallax relations, constructed from ugriz photometry of nearby low-mass stars with trigonometric parallaxes. We use a technique that simultaneously measures Galactic structure and the stellar LF from 7 < Mr < 16. We compare the LF to previous studies and convert to an MF using the mass-luminosity relations of Delfosse et al. The system MF, measured over –1.0< log <–0.1, is well described by a lognormal distribution with = 0.25 . We stress that our results should not be extrapolated to other mass regimes. Our work generally agrees with prior low-mass stellar MFs and places strong constraints on future theoretical star formation studies.
Faculty Start Year
John J. Bochanski, Suzanne L. Hawley, Kevin R. Covey, Andrew A. West, I. Neill Reid, David A. Golimowski, and Željko Ivezić. "The Luminosity and Mass Functions of Low-Mass Stars in the Galactic Disk. II. The Field." The Astronomical Journal 139(6):2679-2699. 2010.