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Y. Rathore, R. D. Blandford (Caltech)
Recent X-ray evidence supports the existence of intermediate mass (~103--105 M\odot) black holes in galaxies, and white dwarfs are known to be common endpoints of stellar evolution. Thus, in general, encounters between intermediate mass black holes and white dwarfs seem unavoidable, and binaries might be formed through gravitational bremsstrahlung or tidal capture. We consider the subsequent orbital evolution in the Newtonian approximation before tidal disruption.
The orbit will evolve rapidly due to gravitational radiation and there will be resonances with internal normal modes of the white dwarf. The modes will in turn affect the orbital evolution through back-reaction. The mode amplitudes may become nonlinear and heat the star through damping or breaking. This could possibly result in a type Ia supernova explosion in a relativistically deep gravitational well. Possible implications of this scenario will be suggested.