Impact of aerosols and adverse atmospheric conditions on the data quality for spectral analysis of the H.E.S.S. telescopes |
| |
| Institution: | 1. Max-Planck-Institut für Kernphysik, P.O. Box 103980, D 69029 Heidelberg, Germany;2. Centre for Space Research, North–West University, Potchefstroom 2520, South Africa;3. I. Physikalisches Institut B, RWTH Aachen University, D 52056 Aachen, Germany;4. DSM/Irfu, CEA Saclay, F-91191 Gif-Sur-Yvette Cedex, France;5. University of Durham, Department of Physics, South Road, Durham DH1 3LE, UK;6. University of Liverpool, Department of Physics, Liverpool L69 7ZE, UK;1. Institute for Experimental Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany;2. Skobeltsyn Institute for Nuclear Physics, Lomonosow Moscow State University, 1 Leninskie gory, 119991 Moscow, Russia;3. DESY, Platanenallee 6, 15378 Zeuthen, Germany;1. RSE Spa, via Rubattino 54, 20134 Milano, Italy;2. ARPA Lombardia Settore Monitoraggi Ambientali, via Juvara 22, 20129 Milano, Italy;3. DICA Politecnico di Milano, P.za L. da Vinci 32, 20133 Milano, Italy;1. Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;2. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China;3. Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan;4. Department of Physics, Shandong University, Jinan 250100, China;5. Institute of Modern Physics, Southwest Jiaotong University, Chengdu 610031, China;6. Physics Department of Science School, Tibet University, Lhasa 850000, China;7. Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan;1. Finnish Environment Institute, Centre for Sustainable Consumption and Production, P.O. Box 140, FI-00251 Helsinki, Finland;2. Finnish Environment Institute, Centre for Freshwater, P.O. Box 140, FI-00251 Helsinki, Finland |
| |
| Abstract: | The Earth’s atmosphere is an integral part of the detector in ground-based imaging atmospheric Cherenkov telescope (IACT) experiments and has to be taken into account in the calibration. Atmospheric and hardware-related deviations from simulated conditions can result in the mis-reconstruction of primary particle energies and therefore of source spectra. During the eight years of observations with the High Energy Stereoscopic System (H.E.S.S.) in Namibia, the overall yield in Cherenkov photons has varied strongly with time due to gradual hardware aging, together with adjustments of the hardware components, and natural, as well as anthropogenic, variations of the atmospheric transparency. Here we present robust data selection criteria that minimize these effects over the full data set of the H.E.S.S. experiment and introduce the Cherenkov transparency coefficient as a new atmospheric monitoring quantity. The influence of atmospheric transparency, as quantified by this coefficient, on energy reconstruction and spectral parameters is examined and its correlation with the aerosol optical depth (AOD) of independent MISR satellite measurements and local measurements of atmospheric clarity is investigated. |
| |
| Keywords: | Cherenkov telescopes Gamma-ray astronomy Aerosols Atmosphere MISR Radiometer |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
