期刊
ASTRONOMICAL JOURNAL
卷 141, 期 3, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/0004-6256/141/3/98
关键词
Galaxy: kinematics and dynamics; methods: statistical; solar neighborhood; stars: fundamental parameters; stars: kinematics and dynamics; stars: low-mass
资金
- NSF [AST 02-05875, AST 06-07644]
- NASA [NAG5-13111]
- Alfred P. Sloan Foundation
- National Science Foundation
- U.S. Department of Energy
- National Aeronautics and Space Administration
- Japanese Monbukagakusho
- Max Planck Society
- Higher Education Funding Council for England
- American Museum of Natural History
- Astrophysical Institute Potsdam
- University of Basel
- University of Cambridge
- Case Western Reserve University
- University of Chicago
- Drexel University
- Fermilab
- Institute for Advanced Study
- Japan Participation Group
- Johns Hopkins University
- Joint Institute for Nuclear Astrophysics
- Kavli Institute for Particle Astrophysics and Cosmology
- Korean Scientist Group
- Chinese Academy of Sciences (LAMOST)
- Los Alamos National Laboratory
- Max-Planck-Institute for Astronomy (MPIA)
- Max-Planck-Institute for Astrophysics (MPA)
- New Mexico State University
- Ohio State University
- University of Pittsburgh
- University of Portsmouth
- Princeton University
- United States Naval Observatory
- University of Washington
We present a statistical parallax analysis of low-mass dwarfs from the Sloan Digital Sky Survey. We calculate absolute r-band magnitudes (M-r) as a function of color and spectral type and investigate changes in M-r with location in the Milky Way. We find that magnetically active M dwarfs are intrinsically brighter in M-r than their inactive counterparts at the same color or spectral type. Metallicity, as traced by the proxy zeta, also affects M-r, with metal-poor stars having fainter absolute magnitudes than higher metallicity M dwarfs at the same color or spectral type. Additionally, we measure the velocity ellipsoid and solar reflex motion for each subsample of M dwarfs. We find good agreement between our measured solar peculiar motion and previous results for similar populations, as well as some evidence for differing motions of early and late M-type populations in U and W velocities that cannot be attributed to asymmetric drift. The reflex solar motion and the velocity dispersions both show that younger populations, as traced by magnetic activity and location near the Galactic plane, have experienced less dynamical heating. We introduce a new parameter, the independent position altitude (IPA), to investigate populations as a function of vertical height from the Galactic plane. M dwarfs at all types exhibit an increase in velocity dispersion when analyzed in comparable IPA subgroups.
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