MEASURING GRAVITATIONAL-WAVES FROM BINARY BLACK-HOLE COALESCENCES - I- SIGNAL-TO-NOISE FOR INSPIRAL, MERGER, AND RINGDOWN

We estimate the expected signal-to-noise ratios (SNRs) from the three phases (inspiral, merger, and ring-own) of coalescing binary black hol es (BBHs) for initial and advanced ground-based interferometers (LIGO- VIRGO) and for the space-based interferometer LISA. Ground-based inter ferometers can do moderate SNR (a few tens), moderate accuracy studies of BBH coalescences in the mass range of a few to about 2000 solar ma sses; LISA can do high SNR (of order 10(4)), high accuracy studies in the mass range of about 10(5)-10(8) solar masses. BBHs might well be t he first sources detected by LIGO-VIRGO: they are visible to much larg er distances-up to 500 Mpc by initial interferometers-than coalescing neutron star binaries theretofore regarded as the ''bread and butter'' workhorse source for LIGO-VIRGO, visible to about 30 Mpc by initial i nterferometers). Low-mass BBHs (up to 50M. for initial LIGO interferom eters, 100M. for advanced, 10(6)M. for LISA) are best searched for via their well-understood inspiral waves; higher mass BBHs must be search ed for via their poorly understood merger waves and/or their well-unde rstood ringdown waves. A matched filtering search for massive BBHs bas ed on ringdown waves should be capable of finding BBHs in the mass ran ge of about 100M.-700M. out to similar to 200 Mpc for initial LIGO int erferometers, and in the mass range of similar to 200M. to similar to 3000M. out to about z=1 for advanced interferometers. The required num ber of templates is of the order of 6000 or less. Searches based on me rger waves could increase the number of detected massive BBHs by a fac tor of the order of 10 over those found from inspiral and ringdown wav es, without detailed knowledge of the waveform shapes, using a noise m onitoring search algorithm which we describe. A full set of merger tem plates from numerical relativity simulations could further increase th e number of detected BBHs by an additional factor of up to similar to 4.