ICRC 2021: Gamma-ray Direct Rapporteur

Abstract

This proceeding is an attempt to overview the space-based gamma-ray astronomy (GAD) presented at the the 37$^{\mathrm{th}}$ International Cosmic Ray Conference held virtually in Berlin. There were 103 abstracts submitted that were self identified under the GAD topic. Because ICRC was held virtually this year, for the first time, the organizers had a unique opportunity to experiment with different formats than previous conferences. For each of the parallel sessions, presenters pre-recorded their talks, and under the GAD heading, there were 121 presentations recorded. This does not include the review and highlight talks which will not be covered in this document. Finally, in lieu of the parallel sessions, the conference was organized into a series of discussion sessions, twelve of which were a GAD specific topic. Each discussion session was organized independently by the convener of that session, and several of the sessions overlapped with other topics. The most overlap occurred with the ground-based gamma-ray astronomy, unsurprisingly, as gamma rays tend to not care which instrument is detecting them. There was also overlap with the new Multimessenger session, the space-based cosmic-ray astronomy session and the dark matter session. Overall space-based gamma-ray astronomy covers a wide range of scientific topics; however, four themes continued to appear: there is unprecedented coverage of the gamma-ray sky, the gamma-ray detecting missions and instruments are mature and well understood, new missions and instruments are coming online, and our current understanding of the sky is leading us to develop new experiments. A virtual conference posed a unique challenge to the organizers; however, I believe the conference organizers, discussion session conveners and the Zoom/Conference support staff did a fabulous job organizing this during these difficult times and I give my sincerest thank you to them.