In the previous triennial period commission J1 on Galaxy Spectral Energy Distributions had two working groups: Reference Library of Galaxy Spectral Energy Distributions (RELIGAS) and From Databases to Spectral Energy Distributions (DB2SED).

Because it was felt that some of the goals of the two groups overlap, it was decided in 2019 to merge the two WGs, but keep the name Reference Library of Galaxy Spectral Energy Distributions (RELIGAS).

One chair from each of the previous working groups was reappointed as chair of the new merged group, while the other two chairs were appointed in advisory roles. As such the chairs of the merged WG are Samir Salim and Carlotta Gruppioni, and the advisors are Anja Schroeder (President Commission B2) and Michael Brown (OC Commission J1).

The new WG has been working to address the following goals:

(i) to analyze the availability and fidelity of observed SEDs of galaxies, and to compare them with what would be necessary to represent the SEDs of actual populations of galaxies (as a function of the environment, mass, redshift, morphology, etc).

(ii) to analyse the availability and fidelity of modeled SEDs and modelling algorithms to represent the SEDs of galaxy populations.

(iii) survey existing databases, models and SED fitting tools and provide recommendations for their use.

Linking the Imprint of Low and High Energy Processes on Galaxy SEDs" is a new working group created in January 2020. The WG is chaired by Dr. Richard Tuffs from the Max- Planck Institute fuer Kernphysik in Heidelberg and Prof. Ellen Zweibel from University of Wisconsin-Madison.

This WG was created with the main goal to explore astrophysical connections between thermal and non-thermal components in galaxies, with the aim of identifying missing links that can be established between the high-energy astrophysics community, in particular the gamma-ray community and the extragalactic community analysing SED of galaxies, in particular the infrared community.