Gravitational waves from gamma-ray bursts

Abstract

We present a mechanism for long bursts of gravitational radiation from Kerr black holes surrounded by a torus. These systems are believed to form in core-collapse of massive stars in association with gamma-ray bursts. The torus catalyzes black hole-spin energy mostly into gravitational radiation, with a minor output in winds, thermal and neutrino emissions. Torus winds impact the remnant envelope of the progenitor star from within, which may account for X-ray emission lines and leaves a supernova remnant. The frequency in gravitational radiation satisfies f_{gw}=470Hz (E_{SNR}/4\times 10^{51})^{1/2}(0.1/β)^{1/2}(7M_\odot/M_H)^{3/2}, where E_{SNR} is the kinetic energy in the SNR, M_H is the black hole mass and β\simeq0.1 the initial ejection velocity, as detected in GRB 011211. Ultimately, this leaves a black hole binary surrounded by a SNR, which is conceivably illustrated by RX J050736-6847.8.