Gravitational wave sources and their detectability

Reviews sources of gravitational radiation that are likely to be detected by gravitational wave detectors now under development. The author first develops back-of-the-envelope formulae that are useful for estimating the strength of gravitational waves and their detectability, i. e. their signal-to-noise ratio in either bar detectors or laser interferometric detectors. It is shown that, provided one can filter wide-band data optimally for a class of signals, the detectability of a signal in a given detector depends only on its distance, its total energy within the detector's bandwidth and (for wide-band detectors) on the dominant frequency of the signal. The author then surveys the most plausible sources: supernovae, coalescing compact-object binaries, neutron stars either spinning down or being by accretion, and the stochastic background. Several important points emerge from comparing detectability. For example, at a given distance, supernovae and coalescing binaries give comparable signals in a typical bar detector, but coalescing binaries are potentially much easier to detect than supernovae using interferometers. As another example, if a supernova is detected, then the subsequent spindown of any newly-formed neutron star may be just as easy to detect, again using an interferometer. The review concludes with an extensive discussion of coalescing binaries, their likely event rates, detection rates and astrophysical importance.