Fast radio bursts are intense, millisecond-duration radio pulses of cosmic origin, often associated with magnetars or other energetic astrophysical events.Fast radio bursts — millisecond radio transients (temporary sources) of cosmological origin. Their dispersion measure (the degree of signal stretching by free electrons in the intergalactic medium) indicates enormous distances. A typical burst releases as much energy in a couple of milliseconds as the Sun emits over several days, suggesting the involvement of compact objects — neutron stars or magnetars (neutron stars with record magnetic fields).
The first detection of FRB 010724 (also known as the Lorimer burst) occurred in 2007 during analysis of data from the Australian Parkes Observatory radio telescope from July 24, 2001. Duncan Lorimer and David Narkevic identified a single pulse with DM=375 pc/cm³, significantly exceeding the Milky Way contribution, indicating an extragalactic origin. Subsequent discoveries with the Arecibo and CHIME telescopes, including the repeating FRB 121102, confirmed the class of phenomena. Theoretical models include explosive scenarios on magnetars (as in the giant flare model), neutron star mergers, or evaporation of primordial black holes. The discovery of FRB-like emission from the galactic magnetar SGR 1935+2154 in 2020 strengthened the magnetar origin hypothesis.
FRB emission is probably generated by a sudden release of magnetic energy in the magnetosphere of a neutron star, leading to a relativistic plasma flow that produces coherent radio emission via cyclotron maser-type instabilities or a synchrotron maser. Alternative models consider shock waves from compact object mergers. Dispersion and Faraday rotation show that the radiation passes through magnetized plasma, imposing constraints on electron density and magnetic fields in the intergalactic medium. The exact emission mechanism is not yet established; key challenges include explaining the coherence of the emission and extreme brightness temperatures.
Used for probing the intergalactic medium and testing cosmological models.
Some fast radio bursts repeat at irregular intervals, like cosmic 'breathing'. The first such repeater, FRB 121102, emitted hundreds of flashes, prompting scientists to build special telescopes to search for them.





















