Stephen Hawking proposed that black holes emit thermal radiation and slowly evaporate over time. This phenomenon, known as Hawking radiation, has remained unproven. However, a team of scientists suggests detecting this radiation may be possible using current telescopes.
The key lies in the aftermath of black hole collisions. When large black holes merge, they may produce tiny, hot “morsel” black holes. Due to their reduced size, these smaller black holes are predicted to emit Hawking radiation more rapidly.
Francesco Sannino, a theoretical physicist at the University of Southern Denmark, explained that they studied the observational impact of these morsel black holes forming during catastrophic events like black hole mergers. Giacomo Cacciapaglia of the French National Centre for Scientific Research noted that only black holes lighter than a few solar masses can emit detectable Hawking radiation.
Morsel black holes and gamma bursts
Such black holes might be produced during mergers and start radiating immediately. The presence of these morsel black holes could be revealed through powerful bursts of high-energy gamma radiation near black hole mergers. As they lose mass, they emit increasingly energetic photons in the trillion electron volts (TeV) energy range.
To detect these events, scientists would look for gravitational waves from black hole mergers followed by gamma-ray observations from ground-based telescopes like the High-Altitude Water Cherenkov gamma-ray Observatory, which can spot photons in the critical energy range. The existence of morsel black holes is a new hypothesis that requires further research and model refinement. Cacciapaglia stated, “There is a long way to go before we can validate Hawking radiation once and for all.
We plan to model the Hawking radiation emission at high energies better and involve experimental collaborations in searching for these unique signatures.”
The team’s research is available as a pre-print paper on the arXiv repository. If their proposed signal is observed, it could rethink our understanding of black holes and morsel production.
