Long gamma-ray bursts (GRBs) have been linked to extreme core-collapse supernovae from massive stars. Gravitational waves (GW) offer a probe of the physics behind long GRBs. We investigate models of long-lived (similar to 10-1000 s) GW emission associated with the accretion disk of a collapsed star or with its protoneutron star remnant. Using data from LIGO's fifth science run, and GRB triggers from the Swift experiment, we perform a search for unmodeled long-lived GW transients. Finding no evidence of GW emission, we place 90% confidence-level upper limits on the GW fluence at Earth from long GRBs for three waveforms inspired by a model of GWs from accretion disk instabilities. These limits range from F <3.5 ergs cm(-2) to F <1200 ergs cm(-2), depending on the GRB and on the model, allowing us to probe optimistic scenarios of GW production out to distances as far as approximate to 33 Mpc. Advanced detectors are expected to achieve strain sensitivities 10X better than initial LIGO, potentially allowing us to probe the engines of the nearest long GRBs.
- gravitational waves
- gamma ray bursts
- massive stars
- LIGO scientific collaboration