Institute for Cosmic Ray Research, University of Tokyo
Institute for Cosmic Ray Research, University of Tokyo
Research School of Astronomy and Astrophysics, Australian National University
School of Chemistry and Physics, University of Adelaide
Narrabri Observatory of the Australia Telescope National Facility, Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Institute for Cosmic Ray Research, University of Tokyo
Department of Physics, Yamagata University
Ibaraki Prefectural University of Health Sciences
Faculty of Management Information, Yamanashi Gakuin University
Department of Physics, Tokai University
出版者
宇宙航空研究開発機構
出版者（英）
Japan Aerospace Exploration Agency (JAXA)
雑誌名
宇宙航空研究開発機構特別資料
雑誌名(英)
JAXA Special Publication: Astrophysics with All-Sky X-Ray observations: 3rd International MAXI Workshop
巻
JAXA-SP-08-014E
ページ
338 - 343
発行年
2009-02-27
会議概要（会議名, 開催地, 会期, 主催者等）（英）
Astrophysics with All-Sky X-Ray observations: 3rd International MAXI Workshop (RIKEN, 10-12 June 2008)
抄録（英）
As accretion and merger shocks in clusters of galaxies may accelerate particles to high energies, clusters are candidate sites for the origin of ultra-high-energy (UHE) cosmic-rays. Recently, a prediction was presented for gamma-ray emission from a cluster of galaxies at a detectable level with modern imaging atmospheric Cherenkov telescopes. The gamma-ray emission was produced via inverse Compton upscattering of cosmic microwave background (CMB) photons by electron-positron pairs generated by collisions of UHE cosmic rays in the cluster. We have observed two clusters of galaxies, Abell 3667 and Abell 4038, searching for very-high-energy gamma-ray emission with the CANGAROO-III atmospheric Cherenkov telescope system in 2006. The analysis showed no significant excess around these clusters, yielding upper limits on the gamma-ray emission. By comparing the upper limit for the north-west radio relic region of Abell 3667 with the model prediction, we can derive a lower limit of the magnetic field of the region of ca. 0.1 microG. This shows the potential of gamma-ray observations in studies of the cluster environment. We also discuss the upper limit from cluster center regions with a model of gamma-ray emission from neutral pion produced in hadronic collisions of cosmic-ray protons with the intra-cluster medium (ICM). The derived upper limit of the cosmic-ray energy density within this framework was one order higher than that of our Galaxy.
内容記述
著者人数: 50人
内容記述（英）
Physical characteristics: Original contains color illustrations
CANGAROO-III search for TeV gamma-rays from two clusters of galaxies
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