Gravitational radiation from gamma-ray burst progenitors

We study gravitational radiation from various proposed gamma-ray burst (GRB) progenitor models, in particular compact mergers and massive stellar collapses. These models have in common a high angular rotation rate, and the final stage involves a rotating black hole and accretion disk system. We consider the in-spiral, merger, and ringing phases, and for massive collapses, we consider the possible effects of asymmetric collapse and break up, as well as bar-mode instabilities in the disks. We evaluate the orders of magnitude of the strain and frequency of the gravitational waves expected from various progenitors, at distances based on occurrence rate estimates. Based on simplifying assumptions, we give estimates of the probability of detection of gravitational waves by the advanced LIGO system from the different GRB scenarios.