Search for pre-burst emission from binary neutron star mergers with Spectrum-Roentgen-Gamma

TL;DR

This paper investigates the potential for detecting pre-merger electromagnetic signals from binary neutron star systems using Spectrum-Roentgen-Gamma, including analysis of a candidate event prior to a known gamma-ray burst.

Contribution

It assesses the capability of SRG telescopes to observe pre-burst emission from BNS mergers and analyzes a specific event potentially related to such emission.

Findings

SRG telescopes can potentially detect pre-merger signals.

Analysis of GRB210919A suggests possible pre-burst emission.

Pre-merger electromagnetic signals remain elusive but detectable with current instruments.

Abstract

Close binary systems consisting of two neutron stars (BNS) emit gravitational waves, that allow them to merge on timescales shorter than Hubble time. It is widely believed, that NS-NS mergers in such systems power short gamma-ray bursts (GRB). Several mechanisms which could lead to electromagnetic energy release prior to a merger have been proposed. We estimate the ability to observe the possible pre-burst emission with telescopes of Spectrum-Roentgen-Gamma. We also investigate first such event, GRB210919A, which fell into the field of view of the SRG telescopes less than two days before the burst.