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Frontier of Energy and Distance of Very High Energy Gamma-Ray Astronomy

Research Project

Project/Area Number 15540263
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Particle/Nuclear/Cosmic ray/Astro physics
Research InstitutionShinshu University

Principal Investigator

KIFUNE Tadashi  Shinshu University, Faculty of Engineering, Professor, 工学部, 教授 (40011621)

Project Period (FY) 2003 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2005: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
KeywordsVery High Energy Gamma Ray Astronomy / Non-thermal Phenomena in the Universe / Particle Acceleration / Origin of Cosmic Rays / Pari production of Electron and Positron / Cosmic Background Radiation / Sources of Very High Energy Gamma Rays / Imaging Atmospheric Cherenkov Telescope / 解像型空気チェレンコフガンマ線望遠鏡 / 超高エネルギーガンマ線源 / 宇宙の非熱的現象 / ガンマ線による電子陽電子対生 / ガンマ線による電子陽電子対生成
Research Abstract

Very energetic gamma rays collide with universal cosmic background radiation of microwave and infrared band to create pairs of electron and positrons, thus initiating a cascade process of creating a number of electrons and gamma rays in the extragalactic space. The effect of absorption and regeneration of gamma-rays which are radiated from far distant sources was calculated, in order to draw a view in near future of TeV Gamma Ray Astronomy and to study ultra high energy phenomena in the Universe.
Regeneration of secondary gamma rays causes accumulation of gamma ray flux in the energy region around 10-100 TeV. However, the increasing factor of the flux is at most about 3 when energy spectrum of primary gamma rays is as hard as the power index alpha of -2, while the factor is less than 10% for in the case of alpha equal to 2.5. On the other hand, more prominent effect of the cosmic cascade can be caused by electrons, the secondary product of the cascade process, of energies higher than 10^{15} eV,. Such high energy electrons radiate synchrotron photons, of which energy would be into the lower energy band as high as GeV gamma rays, possibly to provide evidence of extremely high energy gamma rays. However, the process depends on the strength of magnetic field in the extragalactic space. Thus, there remain investigations to be done in more details. Another interesting feature which may appear is a spectral break in the energy spectrum of electrons, due to the transition from the Thomson scattering to Compton scattering in the collision of electrons with photons of the background radiation.
The cascade process causes a considerable angular spread of incident gamma-rays, and the telescope with a wide field of view is expected to increase importance, as very high energy gamma ray astronomy extends into higher energy region and far distances.

Report

(4 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • Research Products

    (11 results)

All 2005 2004 Other

All Journal Article (5 results) Publications (6 results)

  • [Journal Article] CANGAROO Outcomes and Prospect2005

    • Author(s)
      Tadashi Kifune
    • Journal Title

      Proceedings of Frontier Science 2004 (Frascati Physics Series) XXXVII

      Pages: 351-358

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] CANGAROO Outcomes and Prospect2005

    • Author(s)
      Tadashi Kifune
    • Journal Title

      Frascati Physics Series : Proceedings of Frontier Science Volume XXXVII

      Pages: 351-355

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] CANGAROO : Outcomes and Prospect2005

    • Author(s)
      T.Kifune
    • Journal Title

      Proceedings of Frontier Science 2004 "Physics and Astrophysics in Space" (Frascati Physics Series" by INFN) (印刷中)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] TeV Gamma-Ray Observations and the Origin of Cosmic Rays II2004

    • Author(s)
      Tadashi Kifune
    • Journal Title

      Proceedings of the 28^<th> International Cosmic Ray Conference 8

      Pages: 17-26

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] TeV Gamma Ray Observations and the Origin of Cosmic Rays II2004

    • Author(s)
      Tadashi Kifune
    • Journal Title

      Proceedings of the 28^<th> Cosmic Ray Conference Volume 8

      Pages: 17-26

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Publications] T.Kifune: "TeV Gamma Ray observations and Origin of Cosmic Rays III"Proceedings of 28th Cosmic Ray Conference (Tsukuba). (印刷中). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] Kawachi, A.et al.: "A Search for TeV Gamma-ray Emission from the PSRB1259-63/SS2883 Binary System with the CANGAROO-II 10-m Telescope"Astrophys.J.. 1 June '04(印刷中). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] Enomoto, R.et al.: "Search for TeV gamma-rays from SN1987A in 2001"Astrophys.J.Lett. 591. L25-L28 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Itoh, C.et al.: "Evidence for TeV gamma-ray emission from the nearby starburst galaxy NGC 253"Astronomy and Astrophysics. 402. 443-455 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Kabuki, S.et al.: "Development of an atmospheric Cherenkov imaging camera for the CANGAROO-III experiment"Nucl.Instr.Meth.. A500. 318-336 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] 木舟 正: "宇宙高エネルギー粒子の物理学"培風館. 206 (2004)

    • Related Report
      2003 Annual Research Report

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Published: 2003-04-01   Modified: 2016-04-21  

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