The physical mechanisms of fast radio bursts

Abstract

Fast radio bursts are mysterious millisecond-duration transients prevalent in the radio sky. Rapid accumulation of data in recent years has facilitated an understanding of the underlying physical mechanisms of these events. Knowledge gained from the neighboring fields of gamma-ray bursts and radio pulsars also offered insight. Here I review developments in this fast-moving field.Two generic categories of radiation model invoking either magnetospheres of compact objects (neutron stars or black holes) or relativistic shocks launched from such objects have been much debated. The recent detection of a Galactic fast radio burst in association with a soft gamma-ray repeater suggests that magnetar engines can produce at least some, and probably all, fast radio bursts. Other engines that could produce fast radio bursts are not required, but are also not impossible. On 24 July, 2001, a bright, dispersed radio pulse reached the Parkes 64-m telescope in Australia. The recorded signal remained unnoticed until Duncan Lorimer and his collaborators discovered it (now known as the fast radio burst FRB 010724) several years later and published the results in Science 1. For some time, some astronomers were not convinced that this so-called "Lorimer burst" was a genuine type of astrophysical event, until four more events were reported in 2013 (ref. 2). The field then enjoyed a rapid boost from both observational and theoretical fronts. With the identification of the microwave-oven-origin of some artificial bursts known as "perytons", the astrophysical origin of the bona fide bursts was finally established 3. This was followed by the detection of the first repeating source, known as FRB 121102 (ref. 4) and its localization in a dwarf star forming galaxy at redshift z = 0.19(refs. 5-7), establishing the extragalactic/cosmological origin (in contrast to the Galactic origin 8) of these events. Numerous theoretical models have been proposed to interpret these mysterious events 9. These have been driven by observations and groundbreaking results from numerous radio observatories: Parkes, Arecibo, Green Bank Telescope, the 1

Emission Mechanisms of Fast Radio Bursts

“…Therefore, in a relativistically hot plasma, the curvature emission could be expected to be completely suppressed for a wide range of Γ. If the charge moves with respect to the plasma such that its velocity is out of the range of the plasma thermal velocities, it could emit but the emission rate would be suppressed by a factor (ω /ω p ) 2 ∼ 10 −10 compared with the vacuum emission rate (11). Of course, this highly idealized result could be modified by considering additional effects, such as non-point-like charge distribution, hot plasma, etc.…”

“…A concise summary of observational data, as well as the description of theoretical models is given in ref. [11].…”

Astroparticle Physics with Compact Objects

“…Fast radio bursts (FRBs) are extragalactic radio flares with millisecond duration discovered by [121]. The question of their origin is one of the major astrophysical mysteries nowadays (see reviews, e.g., in [122][123][124]). Axion to photon conversion in a strong magnetic field was one of the first scenarios involving astroparticle physics.…”

The physics of fast radio bursts

“…Efforts of tacking IGM inhomogeneity using the FRB data have been made[287,288] Jaroszynski (2019) [289]. used the Illustris simulation to estimate the DM IGM and its scatters in the z < 5 universe Zhang et al (2020). [283] andTakahashi et al (2020) [290] used the IllustrisTNG simulation to realistically estimate the DM IGM up to z ∼ 9.…”