CASSIS (Centre d’Analyse Scientifique de Spectres Instrumentaux et Synthétiques) is a free, interactive spectrum analyser developed by IRAP-UPS/CNRS. It is a powerful and user-friendly software to efficiently analyse spectral lines, for example to determine physical conditions like column densities and excitation temperatures of different molecules. 

We have developed a simple cookbook that describes how to use CASSIS with a special emphasis on ALMA observations, including instructions on how to extract a spectrum from ALMA data in a format that can be read by CASSIS. The document comes with hands-on practice material that can be downloaded below. The material contains a copy of the cookbook, scripts, an ALMA dataset that can be used to extract a spectrum from, a spectrum formatted for CASSIS, and a folder with codes and files relevant for scripting CASSIS. Detailed instructions on how to install and use CASSIS can be found on the CASSIS website.

Don’t hesitate to e-mail us if you would like to use CASSIS on the Allegro computing nodes or if you encounter any issues using the cookbook.

Enjoy CASSIS in the ALMA era!