Prompt Emission from Tidal Disruptions of White Dwarfs by Intermediate Mass Black Holes. (arXiv:1212.5267v1 [astro-ph.HE])

Prompt Emission from Tidal Disruptions of White Dwarfs by Intermediate Mass Black Holes. (arXiv:1212.5267v1 [astro-ph.HE]):
We present a qualitative picture of prompt emission from tidal disruptions of
white dwarfs (WD) by intermediate mass black holes (IMBH). The smaller size of
an IMBH compared to a supermassive black hole and a smaller tidal radius of a
WD disruption lead to a very fast event with high peak luminosity. Magnetic
field is generated in situ following the tidal disruption, which leads to
effective accretion. Since large-scale magnetic field is also produced,
geometrically thick super-Eddington inflow leads to a relativistic jet. The
dense jet possesses a photosphere, which emits quasi-thermal radiation in soft
X-rays. The source can be classified as a long low-luminosity gamma-ray burst
(ll-GRB). Tidal compression of a WD causes nuclear ignition, which is
observable as an accompanying supernova. We suggest that GRB060218 and SN2006aj
is such a pair of ll-GRB and supernova. We argue that in a flux-limited sample
the disruptions of WDs by IMBHs are more frequent then the disruptions of other
stars by IMBHs.