SKIRT output formats

With few exceptions, SKIRT produces data (mock observables and diagnostic information) in two formats:

Tabular data as ASCII text column files, which can easily be processed by many software tools.
Image frames or 3D data cubes in the FITS file format, which is frequently used in astronomy because each pixel can be represented by a floating point value, allowing for a large dynamic range.

The Python language ecosystem has extensive support for both data formats. The almost standard Python package numpy supports reading text column files into numpy arrays, and the well-known astronomy Python package astropy supports reading FITS data into numpy arrays. Once in memory, these data can be further processed at will.

Based on these packages, the Python Toolkit for SKIRT (PTS) offers functions to read SKIRT output files with some extra intelligence (e.g., interpreting units), and it offers high-level commands to rapidly visualize some specific SKIRT output.

While this is all very helpfull, it is often convenient to also have a dedicated FITS viewer available for interactive inspection of FITS files produced by SKIRT. The following sections describe how to install one such viewer, called SAOImage DS9, or DS9 for short.

Using the command line

On Linux distributions such as Ubuntu, DS9 can be installed via the command line as follows:

$ sudo apt-get update
...
$ sudo apt-get install saods9
...

These commands require root access to modify files in the system directories. The "sudo" command takes care of this assuming that the corresponding privileges are enabled for your account. Enter your password (not the root password!) when asked. Also, for each command, you will be prompted with the question "Do you want to continue? [Y/n]". Respond affirmative unless you see a good reason not to.

Once the above commands have completed successfully, you can launch the interactive DS9 program by entering ds9 on the command line.

Using a graphical installer

A graphical installer is available for most platforms (Linux, macOS, Windows). Browse to the SAOImage DS9 download page and select the appropriate operating system version. Once the installer has been downloaded, launch it and follow the instructions.

For example, on macOS, double click the downloaded .dmg file, and in the displayed window, drag the SAOImageDS9.app icon to the Applications folder.