THE FINAL FATES OF ACCRETING SUPERMASSIVE STARS

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 ≳105 M⊙ 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 . With , the star becomes GR unstable during the helium-burning stage at M ≃ 2–3.5 × 105 M⊙. In an extreme case with 10 , the star does not collapse until the mass reaches ≃8.0 × 105 M⊙, 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.

[1]  Gravitational waves from supermassive stars collapsing to a supermassive black hole , 2016, 1606.07147.

[2]  V. Bromm,et al.  Building up the Population III initial mass function from cosmological initial conditions , 2016, 1603.09475.

[3]  N. Yoshida,et al.  FORMATION OF MASSIVE PRIMORDIAL STARS: INTERMITTENT UV FEEDBACK WITH EPISODIC MASS ACCRETION , 2015, 1510.01407.

[4]  Xiaohui Fan,et al.  An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30 , 2015, Nature.

[5]  N. Yoshida,et al.  Primordial star formation under the influence of far ultraviolet radiation: 1540 cosmological haloes and the stellar mass distribution , 2015, 1501.01630.

[6]  V. Springel,et al.  Formation of massive protostars in atomic cooling haloes , 2014, 1409.3572.

[7]  H. Umeda,et al.  STELLAR YIELDS OF ROTATING FIRST STARS. I. YIELDS OF WEAK SUPERNOVAE AND ABUNDANCES OF CARBON-ENHANCED HYPER-METAL-POOR STARS , 2014, Proceedings of the International Astronomical Union.

[8]  E. Tasker,et al.  Formation of an embryonic supermassive star in the first galaxy , 2014, 1404.4630.

[9]  S. Woosley,et al.  THE GENERAL RELATIVISTIC INSTABILITY SUPERNOVA OF A SUPERMASSIVE POPULATION III STAR , 2014, 1402.4777.

[10]  N. Yoshida,et al.  FORMATION OF PRIMORDIAL SUPERMASSIVE STARS BY RAPID MASS ACCRETION , 2013, 1308.4457.

[11]  F. Palla,et al.  Massive black hole factories: Supermassive and quasi-star formation in primordial halos , 2013, 1305.5923.

[12]  W. Schmidt,et al.  Black hole formation in the early Universe , 2013, 1304.0962.

[13]  H. Yorke,et al.  RAPIDLY ACCRETING SUPERGIANT PROTOSTARS: EMBRYOS OF SUPERMASSIVE BLACK HOLES? , 2012, 1203.2613.

[14]  N. Yoshida,et al.  Protostellar Feedback Halts the Growth of the First Stars in the Universe , 2011, Science.

[15]  Yu Feng,et al.  COLD FLOWS AND THE FIRST QUASARS , 2011, 1107.1253.

[16]  Richard G. McMahon,et al.  A luminous quasar at a redshift of z = 7.085 , 2011, Nature.

[17]  N. Yoshida,et al.  Early Black Hole formation by accretion of gas and dark matter , 2009, 0908.0573.

[18]  N. Yoshida,et al.  EVOLUTION OF VERY MASSIVE POPULATION III STARS WITH MASS ACCRETION FROM PRE-MAIN SEQUENCE TO COLLAPSE , 2009, 0902.4573.

[19]  C. McKee,et al.  The Formation of the First Stars. II. Radiative Feedback Processes and Implications for the Initial Mass Function , 2007, 0711.1377.

[20]  K. Nomoto,et al.  Submitted to the Astrophysical Journal on July 13, 2003 Variations in the Abundance Pattern of Extremely Metal-poor Stars and Nucleosynthesis in Population III Supernovae , 2003 .

[21]  K. Omukai,et al.  Formation of the First Stars by Accretion , 2003 .

[22]  Submitted to ApJ Preprint typeset using L ATEX style emulateapj v. 04/03/99 FORMATION OF THE FIRST SUPERMASSIVE BLACK HOLES , 2002 .

[23]  C. Chiosi,et al.  Zero-metallicity stars - II. Evolution of very massive objects with mass loss , 2002, astro-ph/0212057.

[24]  K. Nomoto,et al.  Nucleosynthesis of Zinc and Iron Peak Elements in Population III Type II Supernovae: Comparison with Abundances of Very Metal Poor Halo Stars , 2001, astro-ph/0103241.

[25]  L. Girardi,et al.  Zero-metallicity stars I. Evolution at constant mass , 2001, astro-ph/0102253.

[26]  Achim Weiss,et al.  Stellar Structure and Evolution , 1990 .

[27]  S. Woosley,et al.  The Evolution of Radiation-dominated Stars. I. Nonrotating Supermassive Stars , 1986 .

[28]  Saul A. Teukolsky,et al.  Black Holes, White Dwarfs, and Neutron Stars , 1983 .

[29]  Saul A. Teukolsky,et al.  White Dwarfs and Neutron Stars: The Physics of Compact Objects , 1983 .

[30]  K. Fricke.  Dynamical phases of supermassive stars , 1973 .

[31]  S. Chandrasekhar.  Dynamical Instability of Gaseous Masses Approaching the Schwarzschild Limit in General Relativity , 1964 .

[32]  I. Iben.  Massive stars in quasi-static equilibrium. , 1963 .