Gamma-ray bursts are short and intense flashes of gamma rays, the most energetic form of light. Credit: Science History Images/Alamy Stock Photo
Machine-learning algorithms and observational data have helped astrophysicists identify two distinct classes of kilonova-associated gamma-ray bursts (GRBs), one of the most energetic explosions in the universe1.
A kilonova (KN) is a transient event that occurs when two compact objects, such as neutron stars, merge. The mergers emit short GRBs and strong electromagnetic radiation, creating elements heavier than iron.
GRB observations provide a valuable tool to study the early universe.
A team of researchers at the Aryabhatta Research Institute of Observational Studies in Nainital analysed a catalogue of prompt-emission light curves of 1,525 GRBs. The Burst Alert Telescope onboard the Swift spacecraft detected the GRBs between 17 December 2004 and 15 July 2022.
An algorithm-based analysis revealed five distinct clusters of GRBs with the KN-associated GRBs located in two separate clusters, which may indicate different progenitors.
The researchers say the clusters may have come from mergers between two neutron stars or between a neutron star and a black hole. The analysis allowed the researchers to zero in on probable candidates of the KN-associated GRBs, including GRBs 130603B, 160821B and 211211A.
The researchers say that next-generation gravitational wave detectors and machine-learning-based methods will likely uncover a bigger landscape of GRBs and their progenitors.
