Fermi GBM Follow-up of LIGO/Virgo Gravitational-wave Candidates
Abstract
The Fermi Gamma-ray Burst Monitor (GBM) is an important tool in the growing area of multimessenger astronomy. With its nearly full-sky continuous observations, Fermi-GBM is able to provide simultaneous observations of gamma-ray bursts (GRBs) with gravitational-wave candidates from the Advanced LIGO and Advanced Virgo instruments. The power of these observations was shown with the detection of GRB 170817A in coincidence with the binary neutron star merger GW170817, which set in motion a large multiwavelength follow-up campaign. Even though the short GRB was likely a result of observing the relativistic jet off-axis, it is the closest known short GRB and was therefore detected onboard GBM. Because most mergers will be observed at farther distance than GW170817, we present a search of the Fermi-GBM continuous data to look for GRBs coincident to gravitational-wave candidates below the onboard triggering threshold. LIGO/Virgo have completed their first and second observing runs and published 25 gravitational-wave candidates. We present the Fermi-GBM subthreshold follow-up of these gravitational-wave candidates. With the third observational run of Advanced LIGO/Virgo in full swing since April 2019 and having produced over 30 public alerts for gravitational wave candidates, we have implemented an updated version of our substhreshold search to automatically follow-up these public alerts. We summarize our results for these public alerts so far, including Fermi GBM-190816 (reported in the GCN Circular 25406), a subthreshold GRB potentially associated with a subthreshold compact binary merger from LIGO/Virgo.
- Publication:
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American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23535102F