Ramses-rt: Radiation hydrodynamics in the cosmological context

J. Rosdahl, J. Blaizot, D. Aubert, T. Stranex, R. Teyssier

Research output: Contribution to journalArticlepeer-review

226 Scopus citations


We present a new implementation of radiation hydrodynamics (RHD) in the adaptive mesh refinement (AMR) code RAMSES. The multigroup radiative transfer (RT) is performed on the AMR grid with a first-order Godunov method using the M1 closure for the Eddington tensor, and is coupled to the hydrodynamics via non-equilibrium thermochemistry of hydrogen and helium. This moment-based approach has the great advantage that the computational cost is independent of the number of radiative sources - it can even deal with continuous regions of emission such as bound-free emission from gas. As it is built directly into RAMSES, theRTtakes natural advantage of the refinement and parallelization strategies already in place. Since we use an explicit advection solver for the radiative transport, the time-step is restricted by the speed of light - a severe limitation that can be alleviated using the so-called reduced speed of light approximation. We propose a rigorous framework to assess the validity of this approximation in various conditions encountered in cosmology and galaxy formation. We finally perform with our newly developed code a complete suite of RHD tests, comparing our results to other RHD codes. The tests demonstrate that our code performs very well and is ideally suited for exploring the effect of radiation on current scenarios of structure and galaxy formation.

Original languageEnglish (US)
Pages (from-to)2188-2231
Number of pages44
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
StatePublished - Dec 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Numerical
  • Radiative transfer - methods


Dive into the research topics of 'Ramses-rt: Radiation hydrodynamics in the cosmological context'. Together they form a unique fingerprint.

Cite this