The Binary Fraction of Low-mass White Dwarfs
Abstract
We describe spectroscopic observations of 21 low-mass (<=0.45 M sun) white dwarfs (WDs) from the Palomar-Green survey obtained over four years. We use both radial velocities and infrared photometry to identify binary systems, and find that the fraction of single, low-mass WDs is <=30%. We discuss the potential formation channels for these single stars including binary mergers of lower-mass objects. However, binary mergers are not likely to explain the observed number of single low-mass WDs. Thus, additional formation channels, such as enhanced mass loss due to winds or interactions with substellar companions, are likely.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2011
- DOI:
- arXiv:
- arXiv:1101.5169
- Bibcode:
- 2011ApJ...730...67B
- Keywords:
-
- stars: evolution;
- stars: low-mass;
- white dwarfs;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 9 pages, accepted to ApJ
