Uncovering low-level Fermi/GBM emission using orbital background subtraction

TL;DR

This paper introduces an orbital background subtraction method for Fermi/GBM to better detect low-level gamma-ray emissions, improving background modeling for long-duration transient events.

Contribution

It presents a novel orbital background subtraction technique to accurately identify low-level emissions in Fermi/GBM data, surpassing traditional polynomial background models.

Findings

Enhanced detection of low-level gamma-ray emission.

Improved background estimation for long-duration events.

Better discrimination between instrumental background and true signals.

Abstract

The secondary instrument onboard Fermi, the Gamma-ray Burst Monitor (GBM) is an all sky monitor consisting of 14 scintillation detectors. When analysing transient events such as Gamma-Ray Bursts (GRBs) and Solar Flares (SFs) the background is usually modelled as a polynomial (order 0-4). However, for long events the background may vary more than can be accounted for with a simple polynomial. In these cases a more accurate knowledge of GBM's background rates is required. Here we present an alternative method of both determining the background and distinguishing low-level emission from the instrumental background.