Localization and Broadband Follow-Up of the Gravitational-Wave Transient Gw150914

Abstract

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground-and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams.

Calibration of the Advanced LIGO detectors for the discovery of the binary black-hole merger GW150914

“…VI. The absolute time of detectors' data streams is accurate to within 10 μs, which does not limit the uncertainty in sky-location parameters for GW150914 [31,34]. Further, the phase uncertainty of the response function as shown in Sec.…”

Localization of binary neutron star mergers with second and third generation gravitational-wave detectors

“…Despite the expectation that stellar mass BBH mergers do not produce electromagnetic signals, there was broadband follow-up of GW150914 [13]. This demonstrated the willingness of the wider astronomical community to engage in multimessenger observation of GW sources.…”

UFFO/Lomonosov: The Payload for the Observation of Early Photons from Gamma Ray Bursts

“…GRBs are believed to be sources of ultra-high energy cosmic rays (UHECR) (Waxman 2006;Abu-Zayyad et al 2012;Tokuno et al 2012;Abraham et al 2004;Panasyuk et al 2012;Takahashi 2009;Halzen and Klein 2010;Gorham et al 2009) and gravitational waves (GW) whose detection has been reported recently (Cutler and Thorne 2002;Abramovici et al 1992;Abbott et al 2016a), and is a prime example of multi-messenger astronomy. The rapid-response in the observation of electromagnetic counterparts to GW (Abbott et al 2016b) is important to obtain the rich information in physical processes of GRBs giving rise to each messenger and the time delay between them.…”