Search for gravitational-wave signals associated with gamma-ray bursts during the second observing run of Advanced LIGO and Advanced Virgo

Abstract

We present the results of targeted searches for gravitational wave transients associated with gammaray bursts during the second observing run of Advanced LIGO and Advanced Virgo, which took place from November 2016 to August 2017. We have analyzed 98 gamma-ray bursts using an unmodeled search method that searches for generic transient gravitational waves and 42 with a modeled search method that targets compact-binary mergers as progenitors of short gamma-ray bursts. Both methods clearly detect the previously reported binary merger signal GW170817, with p-values of <9.38 × 10 −6 (modeled) and 3.1 × 10 −4 (unmodeled). We do not find any significant evidence for gravitationalwave signals associated with the other gamma-ray bursts analyzed, and therefore report lower bounds on the distance to each of these, assuming various source types and signal morphologies. Using our final modeled search results, short gamma-ray burst observations, and assuming binary neutron star progenitors, we place bounds on the rate of short gamma-ray bursts as a function of redshift for z ≤ 1. We estimate 0.07-1.80 joint detections with Fermi-GBM per year for the 2019-20 LIGO-Virgo observing run and 0.15-3.90 per year when current gravitational-wave detectors are operating at their design sensitivities.

First joint observation by the underground gravitational-wave detector, KAGRA, with GEO600

“…This analysis is called PyGRB [89,105], and forms part of the larger PyCBC analysis toolkit [114] with key components in the LALSuite library [115]. This approach has been used in many previous observing runs of the LIGO and Virgo detectors [38][39][40][41] and here we deploy a PyGRB analysis that is functionally identical to that used in the most recent LIGO-Virgo analyses [40,41],…”

“…X-Pipeline [85,94] is an analysis package that combines data from multiple detectors coherently to detect minimally modeled GW transient signals associated with events such as GRBs, core-collapse supernovae, and fast radio bursts. It is used regularly for such searches of LIGO-Virgo data [31,[38][39][40][143][144][145].…”

“…Two of these scan all of the data for signals arriving from any direction at any time: a search for binary NS (BNS) coalescences [2,3,33,34], and a search for generic unmodeled short transients (bursts) [35][36][37]. The other two analyses are dedicated searches for binary coalescence signals and GW bursts associated with GRB events observed during the joint run [38][39][40][41]. No significant candidate GW events are identified, which is expected given the sensitivity of KAGRA at this early stage in its commissioning.…”

Evaluation of Automated Fermi GBM Localizations of Gamma-ray Bursts

“…Mong et al 2019;Ulaczyk et al 2019). Finally, searches for counterparts to detections in other instruments, from radio to gamma-ray and including gravitational-wave and neutrino instruments, utilize GBM GRB localizations (Abbott et al 2017b;Cunningham et al 2019;Ho et al 2019;Abbott et al 2019).…”