Influence of the Earth on the background and the sensitivity of the GRM and ECLAIRs instruments aboard the Chinese-French mission SVOM

TL;DR

This paper investigates how Earth's position affects the gamma-ray background and sensitivity of SVOM's instruments, impacting their ability to detect gamma-ray bursts during the satellite's orbit.

Contribution

It provides the first detailed analysis of Earth's influence on the background noise and detection sensitivity of the GRM and ECLAIRs instruments aboard SVOM.

Findings

Earth crossing the field of view increases gamma-ray background.

Earth's position significantly affects instrument sensitivity.

Estimated impact on GRB detection capability.

Abstract

SVOM (Space-based multi-band astronomical Variable Object Monitor) is a future Chinese-French satellite mission which is dedicated to Gamma-Ray Burst (GRB) studies. Its anti-solar pointing strategy makes the Earth cross the field of view of its payload every orbit. In this paper, we present the variations of the gamma-ray background of the two high energy instruments aboard SVOM, the Gamma-Ray Monitor (GRM) and ECLAIRs, as a function of the Earth position. We conclude with an estimate of the Earth influence on their sensitivity and their GRB detection capability.