We use a large range of software, both (co-)developed by members of the group, and also as pure users of external packages.


We use a heavily modified version of the adaptive mesh refinement code RAMSES to make models of the interstellar medium, ranging from kilo parsec scale boxes containing a piece of the galactic disks, to parsec-sized models of individual forming stars clusters. The changes include

  • A sink particle module to describe stars, including gas-accretion and supernovae feedback.
  • A radiative transfer module using a ray-based long characteristics approach.
  • A new zoom-in AMR mode, that makes it possible to make a layered set of refinements around a single star enabling a dynamic range of up to a billion.
  • Cooling and heating tables appropriate for the interstellar medium.
  • A detailed account of hydrogen in the EOS, including molecular, atomic and ionized states.
  • Pervasive hybridization of the code using OpenMP on top of MPI. The OpenMP part now scales so well that we routinely only use one MPI thread per CPU socket.
  • Many small performance optimizations, including vectorization of the MHD solvers.
  • Rewrite of the Conjugate Gradient Poisson solver using a linear layout and a specially optimized ghost-zone exchange with overlap of computation and communication.
  • New load balance algorithms for better scaling on large number of MPI threads.
  • Flexible restart options, making it possible to both increase and decrease the number of threads.
  • On-the-fly re-reading of namelist parameters.
  • New AMR refinement rules.



The Photon-Plasma Code is a versatile particle-in-cell framework for making kinetic simulations describing in detail the micro-physics in plasma processes. The code has recently been made public available, and can be downloaded here. The code is described in detail in this article.



RAD-MC and LIME are used to post-process RAMSES data for comparison with observations.