The final fates of accreting supermassive stars
- Department of Astronomy, The University of Tokyo, Tokyo 113-0033 (Japan)
- Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
- Astronomical Institute, Tohoku University, Sendai 980-8578 (Japan)
- Department of Physics and Research Center for the Early universe, The University of Tokyo, Tokyo 113-0033 (Japan)
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 calculate the evolution of rapidly accreting SMSs by solving the stellar structure equations including nuclear burning as well as general relativistic (GR) effects up to the onset of the collapse. We find that such SMSs have a less concentrated structure than a fully convective counterpart, which is often postulated for non-accreting ones. This effect stabilizes the stars against GR instability even above the classical upper mass limit ≳10{sup 5} M {sub ⊙} derived for the fully convective stars. The accreting SMS begins to collapse at the higher mass with the higher accretion rate. The collapse occurs when the nuclear fuel is exhausted only for cases with M-dot ≲0.1 M{sub ⊙} yr{sup −1}. With M-dot ≃0.3--1 M{sub ⊙} yr{sup −1}, the star becomes GR unstable during the helium-burning stage at M ≃ 2–3.5 × 10{sup 5} M {sub ⊙}. In an extreme case with 10 M{sub ⊙} yr{sup −1}, the star does not collapse until the mass reaches ≃8.0 × 10{sup 5} M {sub ⊙}, where it is still in the hydrogen-burning stage. We expect that BHs with roughly the same mass will be left behind after the collapse in all the cases.
- OSTI ID:
- 22868560
- Journal Information:
- Astrophysical Journal Letters, Vol. 830, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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