A scheme for radiation pressure and photon diffusion with the M1 closure in RAMSES-RT

J. Rosdahl, R. Teyssier

Research output: Contribution to journalArticlepeer-review

136 Scopus citations


We describe and test an updated version of radiation-hydrodynamics in the RAMSES code, that includes three new features: (i) radiation pressure on gas, (ii) accurate treatment of radiation diffusion in an unresolved optically thickmedium, and (iii) relativistic corrections that account for Doppler effects and work done by the radiation to first order in v/c. We validate the implementation in a series of tests, which include a morphological assessment of the M1 closure for the Eddington tensor in an astronomically relevant setting, dust absorption in an optically semithick medium, direct pressure on gas from ionizing radiation, convergence of our radiation diffusion scheme towards resolved optical depths, correct diffusion of a radiation flash and a constant luminosity radiation, and finally, an experiment from Davis et al. of the competition between gravity and radiation pressure in a dusty atmosphere, and the formation of radiative Rayleigh-Taylor instabilities.With the new features, RAMSES-RT can be used for stateof- the-art simulations of radiation feedback from first principles, on galactic and cosmological scales, including not only direct radiation pressure from ionizing photons, but also indirect pressure via dust from multiscattered IR photons reprocessed from higher-energy radiation, both in the optically thin and thick limits.

Original languageEnglish (US)
Pages (from-to)4380-4403
Number of pages24
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
StatePublished - Mar 21 2015
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Methods: numerical
  • Radiative transfer


Dive into the research topics of 'A scheme for radiation pressure and photon diffusion with the M1 closure in RAMSES-RT'. Together they form a unique fingerprint.

Cite this