EXPLICIT-IMPLICIT SCHEME FOR RELATIVISTIC RADIATION HYDRODYNAMICS

Journal Article · Wed Feb 20 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/764/2/122· OSTI ID:22167757

Takahashi, Hiroyuki R. ^[1]; Ohsuga, Ken; Tomida, Kengo ^[2]; Sekiguchi, Yuichiro ^[3]; Inoue, Tsuyoshi ^[4]

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1. Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)
2. Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)
3. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
4. Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Sagamihara 229-8558 (Japan)

We propose an explicit-implicit scheme for numerically solving special relativistic radiation hydrodynamic equations, which ensures a conservation of total energy and momentum (matter and radiation). In our scheme, zeroth and first moment equations of the radiation transfer equation are numerically solved without employing a flux-limited diffusion approximation. For an hyperbolic term, of which the timescale is the light crossing time when the flow velocity is comparable to the speed of light, is explicitly solved using an approximate Riemann solver. Source terms describing an exchange of energy and momentum between the matter and the radiation via the gas-radiation interaction are implicitly integrated using an iteration method. The implicit scheme allows us to relax the Courant-Friedrichs-Lewy condition in optically thick media, where heating/cooling and scattering timescales could be much shorter than the dynamical timescale. We show that our numerical code can pass test problems of one- and two-dimensional radiation energy transport, and one-dimensional radiation hydrodynamics. Our newly developed scheme could be useful for a number of relativistic astrophysical problems. We also discuss how to extend our explicit-implicit scheme to the relativistic radiation magnetohydrodynamics.

• OSTI ID: 22167757
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 764; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
APPROXIMATIONS
ASTRONOMY
ASTROPHYSICS
COMPARATIVE EVALUATIONS
COOLING
COSMIC GASES
COSMIC RAY FLUX
DIFFUSION
HEATING
MAGNETOHYDRODYNAMICS
RADIANT HEAT TRANSFER
RELATIVISTIC RANGE
SCATTERING
VISIBLE RADIATION