advanced radiative transfer in dusty systems
The home of the SKIRT project
© Astronomical Observatory, Ghent University.
SKIRT renderings of the simulated Eris galaxy (Guedes et al. 2011) in optical and far-infrared wavelengths.



The SKIRT project offers state-of-the-art software for simulating radiation transfer in dusty astrophysical systems such as galaxies, accretion disks, or star forming regions. At the project's heart is the C++ SKIRT code, which employs the Monte Carlo technique to emulate the relevant physical processes including scattering, absorption and emission by the transfer medium. The code features a wealth of built-in geometries, radiation sources, dust characterizations, spatial grids, and detectors, in addition to various mechanisms for importing models generated by hydrodynamical simulations. The configuration for a particular simulation is defined in a parameter file that can be constructed through a user-friendly command-line Q&A session, or with an optional graphical interface.

Another optional component of the SKIRT project is the "Python Toolkit for SKIRT", or PTS. The Python code in this toolkit can help prepare, postprocess, and visualize SKIRT-related data, or it can execute SKIRT simulations in automated contexts.

The SKIRT project is fully open source, including all C++ and Python code and the contents of this web site, and publicly available under liberal licensing conditions (see Legal Information). We invite you to use the SKIRT project's software for your work, and to interact with other users and/or contribute to the project (see Contributing). Results of applying SKIRT to various astrophysical models have been reported in over 50 refereed publications so far (see Publications).

Project versions

This web site includes documentation for two versions of the SKIRT project.

Version 8: mature and stable
Version 9: new and exciting

SKIRT 8 is a mature and stable dust continuum radiative transfer code. It is fully documented and has been actively used for science applications for over a year without reports of any significant problems.

The corresponding PTS code historically did not carry a version number but as of now is informally labeled "version 8" for clarity. In addition to supporting basic SKIRT-related functions, it includes modules for working with astronomical data and for advanced modeling.

SKIRT 8 and PTS 8 are now in maintenance mode. We do not plan to add new features to version 8 of the code base. On the other hand, signifant problems will still be addressed if and when the need arises.

SKIRT 9 is a new and exciting version of the code that has been redesigned to allow a wider range of physics. It already implements kinematics, and the long-term goal is to include extra dust physics (e.g., polarization caused by aligned spheroidal dust grains) and other transfer media (e.g., some aspects of hydrogen line transfer).

SKIRT 9 has been extensively tested in the lab and it runs all available benchmarks. It is also fully documented, including up-to-date tutorials, concept notes and reference material. This new version is now being used for its first actual science projects.

PTS 9 is the corresponding new version of the Python toolkit. It also underwent a substantial redesign, and includes the full subset of functionality directly related to SKIRT.

Navigating this web site

You can navigate the SKIRT project web site by clicking the tabs in the bar at the top of each page. The three leftmost tabs allow you to come back to this home page and to select the respective entry pages for project versions 8 or 9. The other tabs adjust depending on where you are in the web site.

At the top level you'll find pages common to the complete project, including legal and contact information, guidelines for contributing to the project, and a list of related publications. At the first level down, for each version of the SKIRT project, you'll find pages with introductory material, tutorials, benchmark information, download links, and access points to more in-depth information on each of SKIRT and PTS. This in-depth documentation resides at the deepest level of the web site, offering an installation guide, a user guide, a developer guide, and full reference material for each project component and version.

Common information:
  • Contributing – information on how to interact with other SKIRT users and how to contribute to the project.
  • Publications – a list of refereed publications related to or applying the SKIRT project.
  • Legal Information – licensing conditions for the SKIRT project and contact information for the core SKIRT team.
Project version 8: Project version 9:

Source code repositories

The source code for the various SKIRT project components is hosted at in the following repositories.

Project version 8: Project version 9: