On the consequences of low-mass white dwarf mergers
- Illinois Univ., Urbana (USA) Pennsylvania State Univ., University Park (USA)
The theory of binary star evolution suggests that about 10 percent of all main-sequence binary systems should evolve into a close pair of light white dwarfs which merge within a Hubble time. This paper explores the consequences of such mergers on the assumption that a merger can be approximated by a mass-transfer event which occurs on a time scale shorter than that given by the Eddington accretion limit. The evolution of He + He mergers and of CO + He and of hybrid + He mergers are discussed. The birthrate of helium degenerate pairs which merge in less than a Hubble time is estimated, and the space density of low-luminosity merger products currently present in the Galaxy is predicted. It is shown that the evolutionary tracks of models of simulated mergers pass through the region in the H-R diagram occupied by subdwarfs, but that the predicted space density of merger products exceeds by over a factor of three the space density of subdwarf estimated form the known sample of such stars. 61 refs.
- OSTI ID:
- 7041807
- Journal Information:
- Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 353; ISSN ASJOA; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Discovery of a Detached, Eclipsing 40 Minute Period Double White Dwarf Binary and a Friend: Implications for He+CO White Dwarf Mergers
Most double degenerate low-mass white dwarf binaries merge
Related Subjects
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BASIC INTERACTIONS
BINARY STARS
DIAGRAMS
DWARF STARS
EDDINGTON THEORY
ELEMENTS
FLUIDS
GASES
GRAVITATIONAL INTERACTIONS
HELIUM
HERTZSPRUNG-RUSSELL DIAGRAM
INTERACTIONS
MAIN SEQUENCE STARS
MASS
MASS TRANSFER
NONMETALS
ORIGIN
RARE GASES
STAR ACCRETION
STAR EVOLUTION
STARS
WHITE DWARF STARS