3D continuum radiative transfer in dusty systems
The official home of SKIRT
© 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 code for simulating continuum radiation transfer in dusty astrophysical systems, such as galaxies and accretion disks. SKIRT employs the Monte Carlo technique to emulate the relevant physical processes including scattering, absorption and emission by the dust. The code features a wealth of built-in geometries, light source spectra, dust characterizations, dust grids, and detectors, in addition to various mechanisms for importing models generated by hydrodynamical simulations. The configuration for a particular simulation is defined through a user-friendly command-line Q&A session, or with an optional graphical interface called MakeUp.

SKIRT features

Among other things, SKIRT:

The SKIRT project source tree includes FitSKIRT, an extension of the SKIRT code that automatically fits a 3D model to observed images of a dusty astrophysical object. FitSKIRT matches the output frames of SKIRT radiative transfer simulations to the observed images, searching the model parameter space through a genetic algorithm. For each new individual constructed by the genetic procedure, FitSKIRT performs a SKIRT simulation using the parameters defined by the individual's genes. The resulting simulated images are compared with the observed target images, and the result is fed back into the genetic algorithm as the quality measure for the individual.

The SKIRT project is completely written in C++ and has been designed with well-defined programming interfaces between components. Adding a new feature is usually as simple as adding another class; the user interface automatically adjusts to allow configuring the new options.

Python toolkit for SKIRT

As an other extension to SKIRT, the "Python Toolkit for SKIRT" (PTS) helps preprocess, postprocess and visualize SKIRT data, and helps drive SKIRT simulations in various contexts. As its name implies, PTS is written in Python. It is organized as a separate project source tree. Installing PTS is optional – you can perfectly run SKIRT without it.


The source code for the SKIRT and PTS projects is publicly available under the terms defined in the section Legal Information. The projects are hosted at GitHub.com in the following repositories:

This web site offers the documentation for the SKIRT and PTS projects, and is structured as follows:

You can also access these pages by selecting the corresponding tab in the navigation bar at the top of this page.