Searching for electromagnetic counterpart of LIGO gravitational waves in the Fermi GBM data with ADWO

¹ Dept. of Physics of Complex Systems, Eötvös University, 1053 Budapest, Hungary
e-mail: zsolt.bagoly@elte.hu
² Argelander-Institut für Astronomie der Universität Bonn, 53113 Bonn, Germany
³ Konkoly Observatory, RCAES, Hungarian Academy of Sciences, 1051 Budapest, Hungary
⁴ National University of Public Service, 1083 Budapest, Hungary
⁵ Geodetic and Geophysical Institute, RCAES, Hungarian Academy of Sciences, 1051 Budapest, Hungary

Received: 21 March 2016
Accepted: 17 August 2016

Abstract

Aims. The Fermi collaboration identified a possible electromagnetic counterpart of the gravitational wave event of September 14, 2015. Our goal is to provide an unsupervised data analysis algorithm to identify similar events in Fermi’s Gamma-ray Burst Monitor CTTE data stream.

Methods. We are looking for signals that are typically weak. Therefore, they can only be found by a careful analysis of count rates of all detectors and energy channels simultaneously. Our Automatized Detector Weight Optimization (ADWO) method consists of a search for the signal, and a test of its significance.

Results. We developed ADWO, a virtual detector analysis tool for multi-channel multi-detector signals, and performed successful searches for short transients in the data-streams. We have identified GRB150522B, as well as possible electromagnetic candidates of the transients GW150914 and LVT151012.

Conclusions. ADWO is an independently developed, unsupervised data analysis tool that only relies on the raw data of the Fermi satellite. It can therefore provide a strong, independent test to any electromagnetic signal accompanying future gravitational wave observations.