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Title: Numerical simulations of optically thick accretion onto a black hole. II. Rotating flow

Journal Article · · Astrophysical Journal
;  [1];  [2]
  1. Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424 (United States)
  2. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)

In this paper, we report on recent upgrades to our general relativistic radiation magnetohydrodynamics code, Cosmos++, including the development of a new primitive inversion scheme and a hybrid implicit-explicit solver with a more general M {sub 1} closure relation for the radiation equations. The new hybrid solver helps stabilize the treatment of the radiation source terms, while the new closure allows for a much broader range of optical depths to be considered. These changes allow us to expand by orders of magnitude the range of temperatures, opacities, and mass accretion rates, and move a step closer toward our goal of performing global simulations of radiation-pressure-dominated black hole accretion disks. In this work, we test and validate the new method against an array of problems. We also demonstrate its ability to handle super-Eddington, quasi-spherical accretion. Even with just a single proof-of-principle simulation, we already see tantalizing hints of the interesting phenomenology associated with the coupling of radiation and gas in super-Eddington accretion flows.

OSTI ID:
22369970
Journal Information:
Astrophysical Journal, Vol. 796, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English