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- Uchiyama Yasunobu
- 立教大学理学部物理学科
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- Tanaka Takaaki
- 京都大学理学研究科物理学第二教室
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- Tajima Hiroyasu
- 名古屋大学・宇宙地球環境研究所
Bibliographic Information
- Other Title
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- 超新星残骸は宇宙線の起源か?
- チョウシンセイ ザンガイ ワ ウチュウセン ノ キゲン カ?
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Abstract
<p>Galactic Cosmic Rays (CRs), mostly CR protons, are accelerated up to a few PeV energies. While it is widely believed that supernova remnants (SNRs) are the sources of Galactic cosmic rays, unequivocal evidence for the acceleration of high-energy protons in SNRs lacked until recently. Inelastic collisions between high-energy protons with nuclei in the interstellar gas produce neutral pions, which in turn decay into gamma rays whose energy and spatial distributions reflect those of parent protons. This offers a compelling way to reveal the acceleration sites of protons. However, the identification of piondecay gamma rays has been tantalizingly difficult since high-energy electrons also produce gamma rays via bremsstrahlung and inverse Compton scattering. Recently, the Fermi-LAT Collaboration has reported on the detection of the characteristic pion-decay feature in the gamma-ray spectra of two SNRs, IC 443 and W44, which are known to be interacting with molecular clouds. It provides direct evidence that cosmic-ray protons are accelerated in SNRs. We describe the Fermi-LAT observations of these objects along with gamma-ray observations of some other remnants and discuss their implications to our understanding of the acceleration of the Galactic CRs.</p>
Journal
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- Butsuri
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Butsuri 72 (9), 649-657, 2017-09-05
The Physical Society of Japan
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Keywords
Details 詳細情報について
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- CRID
- 1390001288048531584
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- NII Article ID
- 40021304381
- 130007419712
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- NII Book ID
- AN00196952
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- ISSN
- 24238872
- 00290181
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- NDL BIB ID
- 028482426
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- Text Lang
- ja
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- Data Source
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- JaLC
- NDL
- CiNii Articles
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- Abstract License Flag
- Disallowed