The Sirens of August: Detection of Five Gravitational Wave Events in August 2017 Is Consistent With A Constant Rate

Document #:

LIGO-T1800529-v3

Document type:

T - Technical notes

Abstract:

In contrast to August 1914, August 2017 was a happy time for gravitational wave astronomy. Of the 11 gravitational waves---10 BBH mergers and one BNS merger---detected to date by the Advanced LIGO and Advanced Virgo instruments, five occurred in August 2017: GW170809, GW170814, GW170817, GW170818, and GW170823. Throughout O2 there were 1, 0, 0, 0, 1, 1, and 5 gravitational waves from merging compact binary systems detected in January, February, March, April, June, July, and August 2017 (we omit May because it comprises negligible observing time; O2 finished in August 2017). In O1 there were 1, 1, and 1 compact binary detections in September, October, and December 2015 (we omit November because it also comprises negligible observing time). Here we show that the outlier of five detections in August is nonetheless consistent with a constant monthly detection rate.

Files in Document:

• sirens.pdf (416.0 kB)

Other Files:

• Hierarchical.ipynb (958.7 kB)

Topics:

• Astrophysics / Multi-messenger
• Compact Binaries

Authors:

• Will Farr
• Jonathan Gair

Notes and Changes:

Code and LaTeX source in git repository at https://git.ligo.org/will-farr/TheSirensOfAugust

This document and attached notebook are from commit a3a3dd5.