The Cosmic Electron Background in Low Energy IACTs. Effect of the Geomagnetic Field

TL;DR

This paper estimates the cosmic electron background for low energy IACTs like MAGIC, highlighting how the geomagnetic field influences background reduction at various locations, which is crucial for gamma-ray detection.

Contribution

It provides a detailed estimation of electron background levels for low energy IACTs and analyzes the geomagnetic field's impact on background reduction.

Findings

Geomagnetic field significantly reduces electron background at certain locations.

Background levels vary depending on the telescope's geographic position.

Results aid in optimizing low energy gamma-ray observations.

Abstract

A new generation of low threshold Imaging Atmospheric Cherenkov Telescopes (IACTs) may reach gamma-ray energies about 10 GeV with high sensitivities and very large collection areas. At these low energies cosmic electrons significantly contribute to the telescope background and are in principle indistinguishable from gamma-rays. In this paper we estimate the electron background expected for two configurations of the low energy IACT MAGIC. We discuss in particular the reduction of the background caused by the geomagnetic field at different locations on the Earth's surface.