“ Hard ” massive black hole ( MBH ) binaries embedded in steep stellar cusps can shrink via three-body slingshot interactions .
We show that this process will inevitably be accompanied by a burst of stellar tidal disruptions , at a rate that can be several orders of magnitude larger than that appropriate for a single MBH .
Our numerical scattering experiments reveal that : 1 ) a significant fraction of stars initially bound to the primary hole are scattered into its tidal disruption loss cone by gravitational interactions with the secondary hole , an enhancement effect that is more pronounced for very unequal-mass binaries ; 2 ) about 25 % ( 40 % ) of all strongly interacting stars are tidally disrupted by a MBH binary of mass ratio q = 1 / 81 ( q = 1 / 243 ) and eccentricity 0.1 ; and 3 ) two mechanisms dominate the fueling of the tidal disruption loss cone , a Kozai non-resonant interaction that causes the secular evolution of the stellar angular momentum in the field of the binary , and the effect of close encounters with the secondary hole that change the stellar orbital parameters in a chaotic way .
For a hard MBH binary of 10 ^ { 7 } { M _ { \odot } } and mass ratio 10 ^ { -2 } , embedded in an isothermal stellar cusp of velocity dispersion \sigma _ { * } = 100 { km s ^ { -1 } } , the tidal disruption rate can be as large as { \dot { N } } _ { * } \sim 1 yr ^ { -1 } .
This is 4 orders of magnitude higher than estimated for a single MBH fed by two-body relaxation .
When applied to the case of a putative intermediate-mass black hole inspiraling onto Sgr A ^ { * } , our results predict tidal disruption rates { \dot { N } } _ { * } \sim 0.05 - 0.1 yr ^ { -1 } .