Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

Abstract

During their first observational run, the two Advanced LIGO detectors attained an unprecedentedsensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-massbinary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) frommerging intermediate mass black hole binaries (IMBHBs). The combined results from two independentsearch techniques were used in this study: the first employs a matched-filter algorithm that uses a bank offilters covering the GW signal parameter space, while the second is a generic search for GW transients(bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes ofIMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100 M⊙, withspins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained tobe less than 0.93 Gpc−3 yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2orders of magnitude over previous upper limits.