White dwarf binaries, mergers, and explosions
Marten van Kerkwijk
University of Toronto
Stars in binaries often have much more exciting lives, deaths, and
afterlives than single ones. I will review the especially varied
possibilities involving white dwarfs, which include revival and total
annihilation. The latter leads to so-called type Ia supernova explosions,
for which empirical calibrations of their luminosities have allowed the
measurement of the acceleration of the expansion of the Universe. The
standard theoretical picture, in which unstable fusion is ignited in
white dwarfs that approach or are made to exceed the largest possible
(Chandrasekhar) mass, can easily reproduce neither the rates nor the
properties of type Ia supernovae. I will suggest that this type of
ignition instead results in rarer, pure deflagration explosions, and that
type Ia supernovae are produced in mergers of similar-mass carbon-oxygen
white dwarfs.
Date: | Friday, 5 April 2013 |
Time: | 14:00 |
Where: | McGill University |
| Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103) |
|