Origin of cosmic magnetic fields and its observational study

• Project/Area Number: 21840028
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nagoya University
• Principal Investigator: TAKAHASHI Keitaro Nagoya University, 大学院・理学研究科, 特任助教 (80547547)
• Project Period (FY): 2009 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥2,171,000 (Direct Cost: ¥1,670,000、Indirect Cost: ¥501,000); Fiscal Year 2010: ¥936,000 (Direct Cost: ¥720,000、Indirect Cost: ¥216,000); Fiscal Year 2009: ¥1,235,000 (Direct Cost: ¥950,000、Indirect Cost: ¥285,000)
• Keywords: 宇宙物理 / 磁場 / ガンマ線バースト

Research Abstract

To investigate the origin of cosmic magnetic fields, I studied how we can measure intergalactic magnetic fields. I proposed a observational method which utilizes delayed gamma-rays from gamma-ray bursts and active galactic nuclei. As a result, it was shown that tiny intergalactic magnetic fields can be measured by observing delayed gamma-rays from bright gamma-ray bursts and flares of active galactic nuclei with ongoing gamma-ray telescopes such as Fermi and MAGIC.

Research Products

• [Journal Article] Probing Early Cosmic Magnetic Fields through Pair Echos from High-Redshift GRBs (2011)
  • Author(s): Keitaro Takahashi, Susumu Inoue,Kiyotomo Ichiki, Takashi Nakamura
  • Journal Title: Monthly Notice of Royal Astronomical Society 410 Pages: 2741-2748
  • Peer Reviewed
• [Journal Article] Probing Early Cosmic Magnetic Fields through Pair Echos from High-Redshift GRBs (2011)
  • Author(s): Keitaro Takahashi, Susumu Inoue, Kiyotomo Ichiki, Takashi Nakamura
  • Journal Title: Monthly Notice of Royal Astronomical Society Volume: 410 Pages: 2741-2748
  • Peer Reviewed
• [Journal Article] CMB Bispectrum of Vector Modes Induced from Primordial Magnetic Fields (2010)
  • Author(s): Maresuke Shiraishi, Daisuke Nitta,Shuichiro Yokoyama, Kiyotomo Ichiki, Keitaro Takahashi
  • Journal Title: Physical Review D 82 Pages: 121301-121301
  • Peer Reviewed
• [Journal Article] Analytic formulae of the CMB bispectra generated from non-Gaussianity in the tensor and vector perturbations (2010)
  • Author(s): Maresuke Shiraishi, Shuichiro Yokoyama,Daisuke Nitta, Kiyotomo Ichiki, Keitaro Takahashi
  • Journal Title: Physical Review D 82 Pages: 103505-103505
  • Peer Reviewed
• [Journal Article] Analytic formulae of the CMB bispectra generated from non-Gaussianity in the tensor and vector perturbations (2010)
  • Author(s): Maresuke Shiraishi, Shuichiro Yokoyama, Daisuke Nitta, Kiyotomo Ichiki, Keitaro Takahashi
  • Journal Title: Physical Review D Volume: 82 Pages: 103505-103505
  • Peer Reviewed
• [Journal Article] CMB Bispectrum of Vector Modes Induced from Primordial Magnetic Fields (2010)
  • Author(s): Maresuke Shiraishi, Daisuke Nitta, Shuichiro Yokoyama, Kiyotomo Ichiki, Keitaro Takahashi
  • Journal Title: Physical Review D Volume: 82 Pages: 121301-121301
  • Peer Reviewed
• [Journal Article] Skewness in CMB temperature fluctuations from curved cosmic (super-) strings (2010)
  • Author(s): Daisuke Yamauchi, Yuuiti Sendouda, Chul-Moon Yoo, Keitaro Takahashi, Atsushi Naruko, Misao Sasaki
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 05 Pages: 33-33
  • Peer Reviewed
• [Journal Article] Analytical model for CMB temperature angular power spectrum from cosmic (super-)strings (2010)
  • Author(s): Daisuke Yamauchi, Keitaro Takahashi, Yuuiti Sendouda, Chul-Moon Yoo, Misao Sasaki
  • Journal Title: Physical Review D Volume: 82 Pages: 63518-63518
  • Peer Reviewed
• [Journal Article] Systematic Study of Gravitational Waves from Galaxy Merger (2010)
  • Author(s): Takahiro Inagaki, Keitaro Takahashi, Shogo Masaki, Naoshi Sugiyama
  • Journal Title: Physical Review D Volume: 82 Pages: 124007-124007
  • Peer Reviewed
• [Journal Article] Can we probe the Lorentz factor of gamma-ray bursts from GeV-TeV spectra integrated over internal shocks? (2010)
  • Author(s): Junichi Aoi, Kohta Murase, Keitaro Takahashi, Kunihito Ioka, Shigehiro Nagataki
  • Journal Title: Astrophysical Journal Volume: 722 Pages: 440-451
  • Peer Reviewed
• [Journal Article] Possible Origins of Dispersion of the Peak Energy--Brightness Correlations of Gamma-Ray Bursts (2010)
  • Author(s): Daisuke Yonetoku, Toshio Murakami, Ryo Tsutsui, Takashi Nakamura, Keitaro Takahashi
  • Journal Title: PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN Volume: 62 Pages: 1495-1507
  • NAID: 10029326822
  • Peer Reviewed
• [Journal Article] Possible effects of pair echoes on gamma-ray burst afterglow emission (2009)
  • Author(s): Kohta Murase, Bing Zhang, Keitaro Takahashi, Shigehiro Nagataki
  • Journal Title: Monthly Notice of Royal Astronomical Society 396 Pages: 1825-1832
  • Peer Reviewed
• [Journal Article] Non-Gaussianity in Cosmic Microwave Background Temperature Fluctuations from Cosmic(Super-)Strings (2009)
  • Author(s): Keitaro Takahashi, et al.
  • Journal Title: Journal of Cosmology and Astroparticle Physics 10 Pages: 3-3
  • Peer Reviewed
• [Journal Article] Cosmological Constraints from calibrated Yonetoku and Amati relation implies Fundamental plane of Gamma-ray bursts (2009)
  • Author(s): Ryo Tsutsui, Takashi Nakamura, Daisuke Yonetoku, Toshio Murakami, Yoshiki Kodama, Keitaro Takahashi
  • Journal Title: Journal of Cosmology and Astroparticle Physics 08 Pages: 15-15
  • Peer Reviewed
• [Presentation] Study of Cosmic Magnetic Fields with Square Kilometer Array (2010)
  • Author(s): 高橋慶太郎
  • Organizer: Japan SKA Workshop 2010
  • Place of Presentation: 国立天文台三鷹キャンパス
  • Year and Date: 2010-11-04
• [Presentation] ブレーザーからの2次ガンマ線による宇宙磁場探索 (2010)
  • Author(s): 高橋慶太郎
  • Organizer: 日本天文学会
  • Place of Presentation: 金沢大学
  • Year and Date: 2010-09-24
• [Presentation] Study of Cosmic Magnetic Fields with Square Kilometer Array (2010)
  • Author(s): Keitaro Takahashi
  • Organizer: AP-RASC 2010
  • Place of Presentation: 富山国際会議場
  • Year and Date: 2010-09-24
• [Presentation] ブレーザーからの2次ガンマ線による宇宙磁場探索 (2010)
  • Author(s): 高橋慶太郎
  • Organizer: 日本物理学会
  • Place of Presentation: 九州工業大学
  • Year and Date: 2010-09-12
• [Presentation] Magnetic Fields from Cosmological Perturbations (2009)
  • Author(s): 高橋慶太郎
  • Organizer: International Workshop on Cosmological Magnetic Fields
  • Place of Presentation: スイス・アスコーナ
  • Year and Date: 2009-06-05
• [Presentation] Magnetic Fields from Cosmological Perturbations (2009)
  • Author(s): Keitaro Takahashi
  • Organizer: International Workshop on Cosmological Magnetic Fields
  • Place of Presentation: アスコナ(スイス)
  • Year and Date: 2009-06-05