Elucidation of neutron star structure due to X-ray burst simulations

• Project/Area Number: 15K05083
• 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: Kyushu University
• Principal Investigator: Masa-aki Hashimoto 九州大学, 理学研究院, 教授 (20228422)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2015: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: compact stars / 中性子星 / X線バースト / Ｘ線バースト / 元素合成 / 核物質の状態方程式 / ニュートリノ放射率 / 状態方程式 / X-線バースト / 中性子星の冷却 / 中性子星の静穏期の光度

Outline of Final Research Achievements

MAXI J0556-332 is the hottest transient accreting neutron star at the beginning f its quiescence. A theoretical model　with crustal heating indicates that additional shallow heat source of Qshallow > 6MeV per accreted nucleon is required　in the shallow outer crust with respect to the deeper star crust by considering the observed decline in accretion rate at the　end of outburst. However, the physical source of this shallow heating is still unclear. In the present investigation, we　performed stellar evolutionary calculations, dopting the effects of outburst behavior of the accretion rate. As a consequence, we find that the quiescent light curve of MAXI J0556-332 can be well explained by the nuclear energy generation due to the hot CNO cycle.

Research Products

• [Journal Article] Quiescent Light Curve of Accreting Neutron Star MAXI J0556-332 (2017)
  • Author(s): Liu, H., Matsuo, Y., Hashimoto, M., Noda, T., Fujimoto, M.Y.
  • Journal Title: JSPJ Volume: 86 Issue: 12 Pages: 123901-123901
  • DOI: 10.7566/jpsj.86.123901
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Neutron star cooling with various super uid and superconducting states: (2017)
  • Author(s): T. Noda, M. Hashimoto, Y. Matsuo, N. Yasutake, T. Maruyama, T. Tatsumi,
  • Journal Title: Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016), Volume: 14 Pages: 1-3
  • Open Access / Int'l Joint Research
• [Journal Article] Big-bang Nucleosynthesis (2017)
  • Author(s): R. Nakamura, M. Hashimoto, R. Ichimasa, K. Arai
  • Journal Title: International Journal of Modern Physics E Volume: ー
  • NAID: 110007881605
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Neutron Star Cooling with Various Superfluid and Superconducting States (2017)
  • Author(s): T. Noda, M. Hashimoto, Y. Matsuo, N. Yasutake, T. Maruyama, T. Tatsumi
  • Journal Title: JPS Conf. Proc. Volume: 14
  • DOI: 10.7566/jpscp.14.020805
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Nucleosynthesis in Asymmetic Core-Collapse Supernovae of Massive Stars (2017)
  • Author(s): S. Fujimoto, M. Ono, M. Hashimoto, K. Kotake
  • Journal Title: JPS Conf. Proc. Volume: 14
  • DOI: 10.7566/jpscp.14.020621
  • Open Access / Acknowledgement Compliant
• [Journal Article] Effects of triple-$\alpha$ and $^{12}$C($\alpha$,$\gamma$)$^{16}$O reaction rates on the supernova nucleosynthesis in a massive star of 25$M_{\odot}$ (2015)
  • Author(s): Y. Kikuchi, M. Hashimoto, M. Ono, and R. Fukuda
  • Journal Title: Prog. Theor. Exp. Phys. Volume: 063E01 Issue: 6 Pages: 1-14
  • DOI: 10.1093/ptep/ptv072
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] クォークの2SC カラー超伝導と核子の超流動を考慮した高密度星の冷却計算 (2017)
  • Author(s): 野田 常雄，安武伸俊，橋本正章，松尾康秀，丸山敏毅，巽敏隆，藤本正行
  • Organizer: 日本天文学 会2017 年春季年会，九州大学
• [Presentation] 近似ネットワークを用いたType I X線バーストシミュレーション (2016)
  • Author(s): 松尾康秀，橋本正章，町田真美，野田常雄，藤本正行
  • Organizer: 日本天文学会2016年秋季大会
  • Place of Presentation: 愛媛大学
  • Year and Date: 2016-09-14
• [Presentation] Production of Li and B in inhomogeneous Big-Bang Nucleosynthesis (2016)
  • Author(s): R. Nakamura, M. Hashimo
  • Organizer: 14th International Symposium on Nuclei in the cosmos XIV
  • Place of Presentation: 朱鷺メッセ(新潟市)
  • Year and Date: 2016-06-19
  • Int'l Joint Research
• [Presentation] Constraints from supernovae and gamma-ray bursts on the variable dark energy density model (2016)
  • Author(s): R. Ichimasa，E.P.B.A. Thushari，M. Hashimoto
  • Organizer: 14th International Symposium on Nuclei in the cosmos XIV
  • Place of Presentation: 朱鷺メッセ(新潟市)
  • Year and Date: 2016-06-09
  • Int'l Joint Research
• [Presentation] 新しい近似ネットワークを用いたX線バーストシミュレーション (2016)
  • Author(s): 松尾康秀，橋本正章，町田真美，野田常雄
  • Organizer: 第122回日本物理学会九州支部例会
  • Place of Presentation: 福岡大学
• [Presentation] Pion凝縮によるニュートリノ放射過程を考慮した静穏期の中性子星光度と観測との比較 (2015)
  • Author(s): 松尾康秀、橋本正章、林田晃太郎、野田常雄、藤本正行
  • Organizer: 第121回日本物理学会九州支部例会
  • Place of Presentation: 九州工業大学
  • Year and Date: 2015-12-05