Swift J1644+57: A White Dwarf Tidally Disrupted by a 104 M ⊙ Black Hole?
Abstract
We propose that the remarkable object Swift J1644+57, in which multiple recurring hard X-ray flares were seen over a span of several days, is a system in which a white dwarf was tidally disrupted by an intermediate-mass black hole. Disruption of a white dwarf rather than a main-sequence star offers a number of advantages in understanding the multiple, and short, timescales seen in the light curve of this system. In particular, the short internal dynamical timescale of a white dwarf offers a more natural way of understanding the short rise times (~100 s) observed. The relatively long intervals between flares (~5 × 104 s) may also be readily understood as the period between successive pericenter passages of the remnant white dwarf. In addition, the expected jet power is larger when a white dwarf is disrupted. If this model is correct, the black hole responsible must have a mass <~ 105 M ⊙.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2011
- DOI:
- 10.1088/0004-637X/743/2/134
- arXiv:
- arXiv:1106.0923
- Bibcode:
- 2011ApJ...743..134K
- Keywords:
-
- accretion;
- accretion disks;
- black hole physics;
- galaxies: nuclei;
- white dwarfs;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in Ap. J