|
|
Paper: |
The Effects of Close Companions on the Magnetic Activity of M Dwarfs |
Volume: |
448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun |
Page: |
1195 |
Authors: |
Morgan, D. P.; West, A. A.; Silvestri, N. M. |
Abstract: |
We present a study of close white dwarf and M dwarf (WD+dM) binary systems that examines the effects that close companions have on magnetic
field generation in M dwarfs. We used a base sample of 1602 white
dwarf — main seqeuence (WDMS) binaries from Rebassa-Mansergas et al. to determine a set of color cuts in u, g, r, i, and z. Then using the Sloan Digital Sky Survey (SDSS) Data
Release 7 (DR7) we constructed a sample of 2292 WD+dM pairs. We
separated the dM and WD from each combined spectrum using an iterative
technique that compared the WD and dM components to best-fit
templates. Using the absolute height above the Galactic Plane as a
proxy for age, and the Hα emission line as an indicator for
magnetic activity, we investigated the age-activity relation for our
sample; spectral types ≤M5. Our results show that early-type M dwarfs in close binary systems have
increased magnetic activity in both magnitude and duration compared to
their field counterparts. However, we begin to see a transition at
spectral type M5 (just past the onset of full convection in M dwarfs), where the magnitude and
duration in close WD+dM binary systems become more comparable to that of the field M dwarfs. |
|
|
|
|