Supernovae in the central parsec: a mechanism for producing spatially anisotropic hypervelocity stars

Several tens of hypervelocity stars (HVSs) have been discovered escaping our Galaxy. These stars share a common origin in the Galactic center and are distributed anisotropically in Galactic longitude and latitude. We examine the possibility that HVSs may be created as the result of supernovae (SNe) occurring within binary systems in a disk of stars around Sgr A∗ over the last 100 Myr. Monte Carlo simulations show that the rate of binary disruption is ∼10−4 yr−1, comparable to that of tidal disruption models. The SN-induced HVS production rate (ΓHVS) is significantly increased if the binaries are hardened via migration through a gaseous disk. Moderate hardening gives ΓHVS ~= 2×10−7 yr−1 and an estimated population of ∼20 HVSs in the last 100 Myr. SN-induced HVS production requires the internal and external orbital velocity vectors of the secondary binary component to be aligned when the binary is disrupted. This leaves an imprint of the disk geometry on the spatial distribution of the HVSs, producing a distinct anisotropy.