English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  General relativistic radiation hydrodynamics of accretion flows: II. Treating stiff source terms and exploring physical limitations

Rödig, C., Zanotti, O., & Alic, D. (2012). General relativistic radiation hydrodynamics of accretion flows: II. Treating stiff source terms and exploring physical limitations. Monthly Notices of the Royal Astronomical Society, 426(2), 1613-1631. doi:10.1111/j.1365-2966.2012.21821.x.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/11858/00-001M-0000-0010-0D03-4 Version Permalink: http://hdl.handle.net/11858/00-001M-0000-0010-0D05-F
Genre: Journal Article

Files

show Files
hide Files
:
1206.6662 (Preprint), 892KB
Name:
1206.6662
Description:
File downloaded from arXiv at 2012-10-15 10:55
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
:
MNRAS26_1613.pdf (Any fulltext), 2MB
Name:
MNRAS26_1613.pdf
Description:
-
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Rödig, Constanze1, Author              
Zanotti, Olindo, Author
Alic, Daniela1, Author              
Affiliations:
1Astrophysical Relativity, AEI-Golm, MPI for Gravitational Physics, Max Planck Society, ou_24013              

Content

show
hide
Free keywords: Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE,General Relativity and Quantum Cosmology, gr-qc
 Abstract: We present the implementation of an implicit-explicit (IMEX) Runge-Kutta numerical scheme for general relativistic hydrodynamics coupled to an optically thick radiation field in two existing GR-hydrodynamics codes. We argue that the necessity of such an improvement arises naturally in astrophysically relevant regimes where the optical thickness is high as the equations become stiff. By performing several 1D tests we verify the codes' new ability to deal with this stiffness and show consistency. Then, still in 1D, we compute a luminosity versus accretion rate diagram for the setup of spherical accretion onto a Schwarzschild black hole and find good agreement with previous work. Lastly, we revisit the supersonic Bondi Hoyle Lyttleton (BHL) accretion in 2D where we can now present simulations of realistic temperatures, down to T~10^6 K. Here we find that radiation pressure plays an important role, but also that these highly dynamical set-ups push our approximate treatment towards the limit of physical applicability. The main features of radiation hydrodynamics BHL flows manifest as (i) an effective adiabatic index approaching gamma_effective ~ 4/3; (ii) accretion rates two orders of magnitude lower than without radiation pressure; (iii) luminosity estimates around the Eddington limit, hence with an overall radiative efficiency as small as eta ~ 10^{-2}; (iv) strong departures from thermal equilibrium in shocked regions; (v) no appearance of the flip-flop instability. We conclude that the current optically thick approximation to the radiation transfer does give physically substantial improvements over the pure hydro also in set-ups departing from equilibrium, and, once accompanied by an optically thin treatment, is likely to provide a fundamental tool for investigating accretion flows in a large variety of astrophysical systems.

Details

show
hide
Language(s):
 Dates: 2012-06-282012-08-162012-102012
 Publication Status: Published in print
 Pages: 15 pages
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: arXiv: 1206.6662
DOI: 10.1111/j.1365-2966.2012.21821.x
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Monthly Notices of the Royal Astronomical Society
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Oxford : Blackwell Science
Pages: - Volume / Issue: 426 (2) Sequence Number: - Start / End Page: 1613 - 1631 Identifier: ISSN: 1365-8711
CoNE: /journals/resource/1000000000024150