Non-stationary hyperaccretion of stellar-mass black holes in three dimensions: torus evolution and neutrino emission

S Setiawan, M Ruffert, H T Janka

Research output: Contribution to journalArticlepeer-review

Abstract

We present three-dimensional hydrodynamic simulations of the evolution of self-gravitating, thick accretion discs around hyperaccreting stellar-mass black holes. The black hole-torus systems are considered to be remnants of compact object mergers, in which case the disc is not fed by an external mass reservoir and the accretion is non-stationary. Our models take into account viscous dissipation, described by an alpha-law, a detailed equation of state for the disc gas, and an approximate treatment of general relativistic effects on the disc structure by using a pseudo-Newtonian potential for the black hole including its possible rotation and spin-up during accretion. Magnetic fields are ignored. The neutrino emission of the hot disc is treated by a neutrino-trapping scheme, and the nu<(&nu;)overbar>-annihilation near the disc is evaluated in a post-processing step. Our simulations show that the neutrino emission and energy deposition by nu(&nu;) over bar -annihilation increase sensitively with the disc mass, with the black hole spin in case of a disc in corotation, and in particular with the alpha-viscosity. We find that for sufficiently large alpha-viscosity, nu(&nu;) over bar -annihilation can be a viable energy source for gamma-ray bursts.

Original languageEnglish
Pages (from-to)753-758
Number of pages6
JournalMonthly Notices of the Royal Astronomical Society
Volume352
Issue number3
DOIs
Publication statusPublished - 11 Aug 2004

Keywords

  • accretion, accretion discs
  • black hole physics
  • hydrodynamics
  • neutrinos
  • gamma-rays : bursts
  • GAMMA-RAY BURSTS
  • ACCRETION DISKS
  • PHYSICAL MODELS
  • STAR MERGERS
  • NEWTONIAN HYDRODYNAMICS
  • STEP
  • RELATIVITY
  • EQUATION
  • MATTER

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