http://arxiv.org/abs/1704.03879
The inferred parameters of the binary black hole GW151226 are consistent with nonzero spin for the most massive black hole, misaligned from the binary’s orbital angular momentum. If the black holes formed through isolated binary evolution from an initially aligned binary star, this misalignment would then arise from a kick imparted to the first-born black hole at its birth during stellar collapse. We use simple kinematic arguments to constrain the characteristic magnitude of this kick, and find that a natal kick $v_k \gtrsim 50$ km/s must be imparted to the black hole at birth to produce misalignments consistent with GW151226. This large natal kick would be difficult to explain within conventional supernova theory. Primordial spin misalignment may be necessary to explain current and future gravitational wave observations.
R. OShaughnessy, D. Gerosa and D. Wysocki
Fri, 14 Apr 17
16/38
Comments: 5 pages, 2 figures