A method to correct IACT data for atmospheric absorption due to the Saharan Air Layer

被引：19

作者：

Dorner, D. ^{[1
]}

Nilsson, K. ^{[2
]}

Bretz, T. ^{[1
]}

机构：

[1] Univ Wurzburg, D-97074 Wurzburg, Germany

[2] Univ Turku, Tuorla Observ, Piikkio 21500, Finland

来源：

ASTRONOMY & ASTROPHYSICS | 2009年 / 493卷 / 02期

关键词：

gamma rays: observations; methods: data analysis; atmospheric effects; techniques: photometric;

D O I：

10.1051/0004-6361:200809618

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Context. Using the atmosphere as a detector volume, Imaging Air Cherenkov Telescopes (IACTs) depend highly on the properties and the condition of the air mass above the telescope. On the Canary Island of La Palma, where the Major Atmospheric Gamma-ray Imaging Cherenkov telescope ( MAGIC) is situated, the Saharan Air Layer ( SAL) can cause strong atmospheric absorption affecting the data quality and resulting in a reduced gamma flux. Aims. To correlate IACT data with other measurements, e. g. long-term monitoring or Multi-Wavelength (MWL) studies, an accurate flux determination is mandatory. Therefore, a method to correct the data for the effect of the SAL is required. Methods. Three different measurements of the atmospheric absorption are performed on La Palma. From the determined transmission, a correction factor is calculated and applied to the MAGIC data. Results. The different transmission measurements from optical and IACT data provide comparable results. MAGIC data of PG 1553+ 113, taken during a MWL campaign in July 2006, were analyzed using the presented method, providing a corrected flux measurement for the study of the spectral energy distribution of the source. Imaging

引用

页码：721 / 725

页数：5

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