The branching ratio of type Ib/c supernovae to gamma-ray burst supernovae

We study the centered and decentered nucleation of black holes in the core collapse of massive stars in binaries. By Bekenstein's gravitational radiation recoil mechanism, a newly nucleated black hole typically leaves the central core prematurely. With low probability, the black hole remains centered and matures into a high-mass black hole that spins rapidly if the binary is compact. GRB 030329/SN 2003dh demonstrates that Type Ib/c supernovae are the parent population of long gamma-ray bursts, whose branching ratio is R=(2-4)x10(-3). We identify R with the low probability of centered nucleation in compact binaries. Decentered events are predicted to produce a single short burst in gravitational radiation. Centered events are predicted to produce a second, long burst in gravitational radiation powered by a luminous black hole. These signatures are of interest to the gravitational wave experiments LIGO, VIRGO, and TAMA.