Studies of X-ray Emission Mechanisms in High Magnetic Fields using Magnetars

• Project/Area Number: 15K05117
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Japan Agency for Marine-Earth Science and Technology (2016-2017); Japan Aerospace EXploration Agency (2015)
• Principal Investigator: NAKAGAWA Yujin 国立研究開発法人海洋研究開発機構, 地球情報基盤センター, 特任技術副主幹 (50513454)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2015: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: マグネター / 超強磁場中性子星 / パルサー / 超強磁場中性紙星

Outline of Final Research Achievements

Magnetars, which are highly magnetized neutron stars with field strengths of ~1e+14 G, show persistent X-ray emission as well as sporadic bursts. I found that the RMS variations for magnetars observed by Suzaku are significantly greater than the values expected from the Poisson distribution. In this study, I found that the RMS variations vary according to rotations of the magnetars. In addition, the RMS variations are well explained by a mathematical model. I proposed a unified view (“Micro-Burst Model”) of both the persistent X-ray emission and the burst emission from magnetars, based on these results and theoretical models.

Research Products

• [Journal Article] Energy-dependent intensity variation of the persistent X-ray emission of magnetars observed with Suzaku (2018)
  • Author(s): Nakagawa Yujin、Ebisawa Ken、Enoto Teruaki
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 1-10
  • DOI: 10.1093/pasj/psy013
  • Peer Reviewed
• [Journal Article] Energy Dependent Intensity Variations of Persistent X-ray Emission of Magnetars (2016)
  • Author(s): Nakagawa Yujin E., Ebisawa Ken
  • Journal Title: Proceedings of Science Volume: Pos(SWIFT 10) Pages: 150-154
  • Peer Reviewed
• [Presentation] 「すざく」衛星によるマグネターのX線定常放射の強度揺らぎの研究 (2015)
  • Author(s): 中川友進
  • Organizer: 中性子星の観測と理論: 研究活性化ワークショップ
  • Place of Presentation: 京都大学
  • Year and Date: 2015-12-22
• [Presentation] 「すざく」衛星によるマグネターのX線定常放射のエネルギー依存性のある強度揺らぎの研究(2) (2015)
  • Author(s): 中川友進, 海老沢研
  • Organizer: 日本天文学会2015年秋季年会
  • Place of Presentation: 甲南大学
  • Year and Date: 2015-09-10