Chairs of the topical panels of the Athena Science Working Group 1 (SWG1) on the “Hot Universe” (see Athena Working Group structure) met with about 30 invited Topical Panel members for a joint workshop at the Sexten Center for Astrophysics (Sesto Pusteria, Italy) from January 8th to 12th titled “Preparing the science of galaxy clusters & WHIM with Athena”.

The meeting started with a session dedicated to the description of the present status of the Athena mission with talks from: the ESA Study Scientist Matteo Guainazzi, from representatives of the Instrument Consortia Didier Barret and Arne Rau and from one of the SWG1 chairs Thomas Reiprich.

Sessions dedicated to each of the 4 Topical Panels, and organized from Topical Panel (TP) chairs, have introduced and discussed the science goals and the ongoing activities to support and to strength the relative science and instrumental requirements. How hydrodynamical simulations can support, and benefit from, Athena observations of the intracluster and warm-hot intergalactic media has been covered in a focused session. The last 1.5 days have been reserved for a joint discussion, that produced a list of actions and suggestions that TP chairs, with the help of their community, will implement in the next few months.

Overall, the quality of the presentations and of the level of discussion has been very appreciated from the participants, making the workshop very useful, productive and even enjoyable, thanks to the very helpful local support from the secretaries of the Sexten-CfA (led by Gabriella Deconi) and its beautiful location in the middle of the Dolomitic Alps.