“If you’ve seen one gamma-ray burst, you’ve seen one gamma-ray burst!” -Common quote among gamma-ray burst astronomers, emphasizing how little we know about them.
When the first gravitational wave signal ever, GW150914, was directly detected, NASA’s Fermi GBM team shocked the world by announcing the detection of a high-energy burst of electromagnetic radiation. This was a huge surprise, because merging black holes shouldn’t have a bright gamma ray or X-ray flash associated with them!
A statistical reanalysis and the ESA’s INTEGRAL satellite both failed to confirm it, but it would take a second event to know for certain. With GW151226 now in the books, a look through the Fermi GBM data shows what we suspected all along: black holes DON’T burst when they merge!