The Pierre Auger Observatory, situated in Argentina, is designed to detect UHE cosmic rays. The observatory is also sensitive to UHE photons and has been used to search for photons from various sources. This study looked for coincidences between UHE photon events and a selection of GW events detected by the LIGO/Virgo observatories. No UHE photon events were observed in coincidence with any of the selected GW events. This is the first study to place limits on UHE photon emission from GW sources.

Publication: Abdul Halim, A., et al. "Search for UHE Photons from Gravitational Wave Sources with the Pierre Auger Observatory.", 2023 ApJ 952 91

Acknowledgements: Podcast prepared with Google/NotebookLM. Illustration credits: A.Chantelauze/S.Staffi/L.Bret