2005 Fiscal Year Final Research Report Summary
Research on cosmic-ray acceleration and propagation by using very high energy (TeV) gamma rays
| Project/Area Number |
16540209
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | Ibaraki University |
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Principal Investigator |
YOSHIDA Tatsuo Ibaraki University, College of Science, Professor, 理学部, 教授 (60241741)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Very high energy (TeV) gamma rays / Particle acceleration / Origin of cosmic rays / Supernova remnants (SNRs) / Galactic center |
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| Research Abstract |
This purpose of this research is to investigate the origin of cosmic rays (CRs), by using very high energy (TeV) gamma rays. The CANGAROO-II Imaging Atomspheric Cherenkov Telescope (IACT) has detected TeV gamma-ray emissions from the Galactic Center and the supernova remnant (SNR) RX J0852.0-4622. I contribute to constructing the nonthermal emission models for radio-to-TeV gamma rays. The modeling of multiband spectra for these objects is necessary for understanding particle acceleration and propagation of the galactic CRs. The CANGAROO team introduced the Fisher discriminant method for bias-free stereoscopic observational analysis. And the CANGAROO-III stereoscopic IACT confirmed the extended TeV gamma-ray emission from the Vela pulsar wind nebula, which was detected by the H.E.S.S. stereoscopic system. We also put constraints on the diffusive shock acceleration by using the Chandra Observation of nonthermal X-ray filaments in young SNRs. Moreover, we discuss a possible origin of the spectral break near PeV (knee) in CR spectrum. We assume the hypothetical extragalactic CRs and investigate effects of their modulation by the galactic wind by using numerical simulations. We found that the knee structure is reproduced by a superposition of the extragalactic modulated CRs and the galactic ones originating from SNRs.
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