Early Attempts at Active Atmospheric Calibration with H.E.S.S. Phase 1

TL;DR

This paper presents an initial method for atmospheric calibration of H.E.S.S. data using ceilometer data and shower reconstruction, improving flux measurements during variable atmospheric conditions.

Contribution

It introduces a novel correction technique for atmospheric variability in gamma-ray observations using combined telescope and ceilometer data.

Findings

Improved flux accuracy during variable atmospheric conditions.

Demonstrated correction method applied to PKS 2155-304 data.

First step towards comprehensive atmospheric calibration.

Abstract

Using data derived from the H.E.S.S. Phase 1 telescope system and a Ceilometer facility on site, a method of correcting for changing atmospheric quality based on reconstructed shower parameters is presented. The method was applied to data from the active galactic nucleus PKS 2155-304, taken during August and September 2004 when the quality of the atmosphere at the site was highly variable. Corrected and uncorrected fluxes are shown, and the method is discussed as a first step towards a more complete atmospheric calibration.