nderstanding the formation mechanisms of compact objects from multi-dimensional stellar evolution history

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H01130
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Fukuoka University
• Principal Investigator: Kotake Kei 福岡大学, 理学部, 教授 (20435506)
• Co-Investigator(Kenkyū-buntansha): 滝脇 知也 国立天文台, 科学研究部, 助教 (50507837) ; 梅田 秀之 東京大学, 大学院理学系研究科(理学部), 准教授 (60447357)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 超新星爆発 / 中性子星 / ブラックホール / 多次元恒星進化

Outline of Final Research Achievements

In order to investigate the multi-dimensional evolution of massive stars prior to　collapse, we have developed 3D hydrodynamics code including an in-situ nuclear burning network calculation. By performing 3D simulations of typical massive stars (22 and 27 solar masses) over a hundred of second before collapse, we have found that the global turbulence develops in the oxygen-silicon layers with a typical Mach number of 0.1. This turbulence is expected to be favorable for the onset of the neutrino-driven supernova explosions. Besides, we have updated our 3D supernova code in such a way to implement the state-of-the-art neutrino opacities. By performing the 3D self-consistent core-collapse simulations, we obtain some major findings including the correlation between the progenitor’s core compactness and the kick velocity of the neutron stars and the new neutrino and gravitational signatures, for the formation of which spiral modes that develop in rapidly rotating cores play a vital role.

Free Research Field

天体物理学

Academic Significance and Societal Importance of the Research Achievements

大質量星の進化計算において、多次元流体運動の時間尺度と核融合の時間尺度が極端に違うため、これまでの3Dの進化計算(特に爆発直前段階において)は、殆ど例がなかった。この課題に取り組むことで、「国産の」3D恒星進化コードを作成できたことは、学術的意義が極めて高い。さらに磁気流体コードを作成できたことも、今後、自転や磁場を伴う大質量星進化の解明に向けた準備が整ったという意味で、大きな学術的収穫である。