Stars approaching supermassive black holes ( SMBHs ) in the centers of galaxies can be torn apart by strong tidal forces .
We study the physics of tidal disruption by a binary SMBH as a function of the binary mass ratio q = M _ { 2 } / M _ { 1 } and separation a , exploring a large set of points in the parameter range q \in [ 0.01 , 1 ] and a / r _ { t 1 } \in [ 10 , 1000 ] .
We simulate encounters in which field stars approach the binary from the loss cone on parabolic , low angular momentum orbits .
We present the rate of disruption and the orbital properties of the disrupted stars , and examine the fallback dynamics of the post-disruption debris in the ‘ ‘ frozen-in ’ ’ approximation .
We conclude by calculating the time-dependent disruption rate over the lifetime of the binary .
Throughout , we use a primary mass M _ { 1 } = 10 ^ { 6 } M _ { \odot } as our central example .
We find that the tidal disruption rate is a factor of \sim 2 - 7 times larger than the rate for an isolated BH , and is independent of q for q \gtrsim 0.2 .
In the ‘ ‘ frozen-in ’ ’ model , disruptions from close , nearly equal mass binaries can produce intense tidal fallbacks : for binaries with q \gtrsim 0.2 and a / r _ { t 1 } \sim 100 , roughly \sim 18 - 40 \% of disruptions will have short rise times ( t _ { \textrm { rise } } \sim 1 - 10 d ) and highly super-Eddington peak return rates ( \dot { M } _ { \textrm { peak } } / \dot { M } _ { \textrm { Edd } } \sim 2 \times 10 ^ { 2 } -3 \times 10 ^ { 3 } ) .