Detection capability of Ultra-Long Gamma-Ray Bursts with the ECLAIRs telescope aboard the SVOM mission

TL;DR

This paper evaluates the detection capabilities of the ECLAIRs telescope on the SVOM mission for ultra-long gamma-ray bursts, proposing methods to improve detection sensitivity and analyzing potential detection success.

Contribution

The paper introduces new image cleaning methods and sensitivity estimates for ULGRB detection with ECLAIRs, enhancing understanding of its detection potential.

Findings

ECLAIRs can detect ULGRBs longer than 2000 seconds.

Developed image cleaning techniques improve detection accuracy.

Sensitivity estimates suggest promising detection rates for ULGRBs.

Abstract

Ultra-long gamma-ray bursts (ULGRBs) have very atypical durations of more than 2000 seconds. Even if their origins are discussed, the SVOM mission with its soft gamma-ray telescope ECLAIRs could detect ULGRBs and increase the sample of the few which have been detected so far by the Burst Alert Telescope aboard the Neil Gehrels Swift Observatory and some other instruments. In this paper, after a short description of the SVOM mission, we present methods developed to clean detector images from non-flat background and known source contributions in the onboard imaging process. We present an estimate of the ECLAIRs sensitivity to GRBs of various durations. Finally we study the capability of the image-trigger to detect ULGRBs.