Detailed Studies of Atmospheric Calibration in Imaging Cherenkov Astronomy

TL;DR

This paper discusses atmospheric calibration techniques for Imaging Atmospheric Cherenkov telescopes, using ceilometers to improve flux accuracy in gamma-ray observations, demonstrated with data from PKS 2155-304.

Contribution

It introduces a method using ceilometers co-pointed with H.E.S.S. telescopes for atmospheric calibration in Cherenkov astronomy, enhancing flux measurement accuracy.

Findings

Ceilometer-based atmospheric calibration reduces systematic errors.

Application to PKS 2155-304 data demonstrates method effectiveness.

Improved flux measurements in gamma-ray astronomy.

Abstract

The current generation of Imaging Atmospheric Cherenkov telescopes are allowing the sky to be probed with greater sensitivity than ever before in the energy range around and above 100 GeV. To minimise the systematic errors on derived fluxes a full calibration of the atmospheric properties is important given the calorimetric nature of the technique. In this paper we discuss an approach to address this problem by using a ceilometer co-pointed with the H.E.S.S. telescopes and present the results of the application of this method to a set of observational data taken on the active galactic nucleus (AGN) PKS 2155-304 in 2004.