The Final Fates of Accreting Super Massive Stars

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400220
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: The University of Tokyo
• Principal Investigator: Umeda Hideyuki 東京大学, 大学院理学系研究科(理学部), 准教授 (60447357)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 超大質量星 / 初代星 / 超大質量ブラックホール / 一般相対論

Outline of Final Research Achievements

The formation of supermassive stars (SMSs) via rapid mass accretion and their direct collapse into black holes (BHs) is a promising pathway for sowing seeds of supermassive BHs in the early universe. We calculated the evolution of rapidly accreting SMSs including general relativistic (GR) effects up to the onset of the collapse. We found that such SMSs have a less concentrated structure than a non-accreting ones. This effect stabilizes the stars against GR instability even above the classical upper mass limit around 100,000 Msun. We found that the final masses for dM/dt = 0.1, 0.3, 1.0 and 10 Msun/yr are 1.2, 1.9, 3.5 and 8.0 times 100,000Msun, respectively. We also found that the GR instability does not occur for the dM/dt=0.1 model. On the other hand, the　instability occurs during He-burning stage for the dM/dt=0.3 and 1.0 models, and during H-burning stage for the dM/dt=10 model. And the reasons for these reseluts were discussed.

Free Research Field

理論天体物理学