Gamma-ray bursts and fast radio bursts are among the most energetic events in the universe. Both release intense radiation in a short time. However, they differ in wavelength, duration and likely origin. Therefore, astronomers study them as separate but related high-energy phenomena.
Gamma-ray bursts, or GRBs, emit brief flashes of gamma rays. Long bursts often last several seconds or more. They are usually linked to the collapse of massive stars. Short bursts last less than two seconds. They are often linked to the merger of compact objects such as neutron stars. As a result, GRBs provide clues about stellar death and extreme gravity.
The central engine of a GRB is thought to launch relativistic jets. These jets move at speeds close to the speed of light. Shock waves inside the jet can accelerate particles. The particles then produce gamma rays. After the main burst, an afterglow can appear in X-ray, optical and radio bands. This afterglow helps researchers estimate distance and energy.
Fast radio bursts, or FRBs, last only milliseconds. They appear as bright pulses in radio wavelengths. Some FRBs repeat. Others appear only once. This difference suggests more than one possible source. Magnetars are a leading candidate for at least some events. In addition, compact-object interactions may explain other bursts.
The radio signal of an FRB travels through ionised plasma. This plasma delays lower frequencies more than higher ones. Astronomers call this effect dispersion. They use it to estimate the distance to the source. Moreover, polarisation and scattering give information about the environment around the burst.
GRBs and FRBs both involve compact objects and extreme magnetic or gravitational conditions. Still, their emission processes are not the same. GRBs release energy mainly at very high photon energies. FRBs release energy in coherent radio waves. Therefore, the two events probe different parts of high-energy astrophysics.
Multi-messenger observations improve this research. Gravitational waves, neutrinos and electromagnetic signals can appear together in some events. Wide-field radio surveys also increase the number of known FRBs. Space-based gamma-ray detectors continue to record new GRBs. Consequently, models of both phenomena are becoming more detailed.
The physics of gamma-ray bursts and fast radio bursts reveals how matter behaves under extreme conditions. These events help scientists study stellar collapse, magnetars and relativistic outflows. Ongoing observations will test current models and refine the link between the two classes of bursts.