The identified gamma-ray extragalactic magnetar giant flare population

Around 11.4 million years ago a magnetar in NGC253 released a huge amount of energy in a giant flare. On April 15th 2020 some of the emitted photons were detected by a number of gamma-ray telescopes, including the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) on the Fermi satellite. The burst GRB200415A provided new insights of magnetar giant flare (MGF) phenomenology. From a population of 7 known MGFs (both Galactic and extragalactic in origin) we derived their intrinsic rates to be R ~ 3.8×10⁵ Gpc^-3 yr^-1, suggesting that according to current instrument capabilities more events should exist in archival Fermi data which are still unidentified. We expect about 10 more events in GBM data with possible higher-energy counterparts in the LAT data. In this contribution we review the current status and future perspectives of the studies involving MGFs and gamma-ray astrophysics.