Swift pointing and the association between gamma-ray bursts and gravitational wave bursts

It is widely believed that gamma-ray bursts originate in relativistic fireballs produced by the merger or collapse of solar-mass compact objects. Gravitational waves should be associated with these violent, relativistic events, and their detection may shed light on the nature of the inner engine that powers the gamma-ray burst. Doing this requires joint observations of gamma-ray burst events with gravitational and gamma-ray detectors. Here we examine how the quality of an upper limit on the gravitational wave strength at Earth associated with gamma-ray burst observations depends on the relative orientation of the gamma-ray burst and gravitational wave detectors, and we apply our results to the particular case of the Swift Burst Alert Telescope and the LIGO gravitational wave detectors. A result of this investigation is a science-based "figure of merit" that can be used, together with other mission constraints, to optimize the pointing of the Swift telescope for the detection of gravitational waves associated with gamma-ray bursts.