Quantifying an Age-Activity Relation using Wide White Dwarf - M Dwarf Binary Pairs
Abstract
Due to the intrinsic faintness of M dwarfs (dM) and the lack of old (> 1 Gyr) nearby open clusters, traditional methods of tying spectroscopically derived properties such as activity to dMs of known ages are infeasible. However, binary systems represent ideal laboratories for investigating age-dependent relations since both components are thought to be coeval. Particularly useful are wide White dwarf+dM (WD+dM) binaries, in which precise WD ages (20-40% uncertainty in total age) can be calculated using cooling models and detailed stellar evolution models. Previous studies have investigated age-activity relationships for isolated dMs, close WD+dM binary pairs, and wide WD+dM pairs. In each case, these studies were limited either by the age-dating methods used or the sample sizes. Our study addresses the deficiencies of prior studies by using a complete spectroscopic sample of wide WD+dM pairs; perfectly isolated coeval laboratories in which to further constrain the M dwarf age-activity relationship. We have compiled a sample of 250 high probability WD+dM pairs from existing common proper motion catalogs. At present, 50 of the pairs have had both components spectroscopically observed with either SDSS or the Perkins 1.83-m telescope at Lowell Observatory. Using our spectroscopic wide WD+dM sample, we relate the magnetic activity (as measured by H-alpha emission) to the WD ages (WD cooling times + progenitor lifetimes) in order to quantify an age-activity relation for M dwarfs with ages > 1 Gyr.
- Publication:
-
American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22344114M