[1206.1056] White Dwarf Kinematics vs Mass

Authors: Christopher Wegg, E. Sterl Phinney

Date: 5 Jun 2012

Abstract: We have investigated the relationship between the kinematics and mass of young (<3x10ˆ8 years) white dwarfs using proper motions. Our sample is taken from the colour selected catalogues of SDSS (Eisenstein et al. 2006) and the Palomar-Green Survey (Liebert, Bergeron & Holberg 2005), both of which have spectroscopic temperature and gravity determinations. We find that the dispersion decreases with increasing white dwarf mass. This can be explained as a result of less scattering by objects in the Galactic disk during the shorter lifetime of their more massive progenitors. A direct result of this is that white dwarfs with high mass have a reduced scale height, and hence their local density is enhanced over their less massive counterparts. In addition, we have investigated whether the kinematics of the highest mass white dwarfs (>0.95Msun) are consistent with the expected relative contributions of single star evolution and mergers. We find that the kinematics are consistent with the majority of high-mass white dwarfs being formed through single star evolution.

abs pdf

Jun 07, 2012

1206.1056 (/preprints)
2012-06-07, 01:09 [edit]


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Tantum in modicis, quantum in maximis