Intrinsic selection biases of ground-based gravitational wave searches for high-mass black hole-black hole mergers

The next generation of ground-based gravitational wave detectors may detect a few mergers of comparable-mass M = 100 - 1000M(circle dot) ["intermediate-mass'' (IMBH)] spinning black holes. Black hole spin is known to have a significant impact on the orbit, merger signal, and post-merger ringdown of any binary with non-negligible spin. In particular, the detection volume for spinning binaries depends significantly on the component black hole spins. We provide a fit to the single-detector and isotropic-network detection volume versus (total) mass and arbitrary spin for equal-mass binaries. Our analysis assumes matched filtering to all significant available waveform power (up to l = 6 available for fitting, but only l <= 4 significant) estimated by an array of 64 numerical simulations with component spins as large as S-1,S-2/M2 <= 0.8. We provide a spin-dependent estimate of our uncertainty, up to S-1,S-2/M-2 <= 1. For the initial (advanced) LIGO detector, our fits are reliable for M is an element of [100, 500]M-circle dot (M is an element of [100, 1600]M-circle dot). In the online version of this article, we also provide fits assuming incomplete information, such as the neglect of higher-order harmonics. We briefly discuss how a strong selection bias towards aligned spins influences the interpretation of future gravitational wave detections of IMBH-IMBH mergers.