GW170608: Observation of a 19-solar-mass Binary Black Hole Coalescence

TL;DR

This paper reports the first observation of a binary black hole merger with component masses around 12 and 7 solar masses, confirming gravitational wave detection and consistency with general relativity.

Contribution

First detection of a lightest black hole binary via gravitational waves, expanding understanding of black hole populations.

Findings

Detected a 19-solar-mass binary black hole coalescence

Component masses are consistent with low-mass X-ray binary black holes

Waveform matches general relativity predictions

Abstract

On June 8, 2017 at 02:01:16.49 UTC, a gravitational-wave signal from the merger of two stellar-mass black holes was observed by the two Advanced LIGO detectors with a network signal-to-noise ratio of 13. This system is the lightest black hole binary so far observed, with component masses $12^{+7}_{-2}\,M_\odot$ and $7^{+2}_{-2}\,M_\odot$ (90% credible intervals). These lie in the range of measured black hole masses in low-mass X-ray binaries, thus allowing us to compare black holes detected through gravitational waves with electromagnetic observations. The source's luminosity distance is $340^{+140}_{-140}$ Mpc, corresponding to redshift $0.07^{+0.03}_{-0.03}$. We verify that the signal waveform is consistent with the predictions of general relativity.