Analysis Framework for the Prompt Discovery of Compact Binary Mergers in Gravitational-wave Data

TL;DR

This paper presents a low-latency, stream-based analysis pipeline for detecting gravitational waves from binary mergers within about a minute, enabling prompt electromagnetic follow-up and operational feedback.

Contribution

It introduces a real-time analysis pipeline capable of rapid gravitational-wave detection and demonstrates its effectiveness through the first identification of GW151226 and other events.

Findings

First to identify GW151226 in real-time

Detected GW150914 and LVT151012 offline

Enabled prompt electromagnetic follow-up

Abstract

We describe a stream-based analysis pipeline to detect gravitational waves from the merger of binary neutron stars, binary black holes, and neutron-star-black-hole binaries within ~ 1 minute of the arrival of the merger signal at Earth. Such low-latency detection is crucial for the prompt response by electromagnetic facilities in order to observe any fading electromagnetic counterparts that might be produced by mergers involving at least one neutron star. Even for systems expected not to produce counterparts, low-latency analysis of the data is useful for deciding when not to point telescopes, and as feedback to observatory operations. Analysts using this pipeline were the first to identify GW151226, the second gravitational-wave event ever detected. The pipeline also operates in an offline mode, in which it incorporates more refined information about data quality and employs acausal methods that are inapplicable to the online mode. The pipeline's offline mode was used in the detection of the first two gravitational-wave events, GW150914 and GW151226, as well as the identification of a third candidate, LVT151012.