A Decade and a Half of Fast Radio Burst Observations

Abstract

Fast radio bursts (FRBs) have a story which has been told and retold many times over the past few years as they have sparked excitement and controversy since their pioneering discovery in 2007. The FRB class encompasses a number of microsecond- to millisecond-duration pulses occurring at Galactic to cosmological distances with energies spanning about 8 orders of magnitude. While most FRBs have been observed as singular events, a small fraction of them have been observed to repeat over various timescales leading to an apparent dichotomy in the population. ∼50 unique progenitor theories have been proposed, but no consensus has emerged for their origin(s). However, with the discovery of an FRB-like pulse from the Galactic magnetar SGR J1935+2154, magnetar engine models are the current leading theory. Overall, FRB pulses exhibit unique characteristics allowing us to probe line-of-sight magnetic field strengths, inhomogeneities in the intergalactic/interstellar media, and plasma turbulence through an assortment of extragalactic and cosmological propagation effects. Consequently, they are formidable tools to study the Universe. This review follows the progress of the field between 2007 and 2020 and presents the science highlights of the radio observations.

A Possible Subclassification of Fast Radio Bursts

“…Although fast radio bursts (FRBs) have been an active field in astronomy and cosmology, their origin is still unknown to date. FRBs are mysterious transient radio sources of millisecond duration [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Most of them are at extragalactic/cosmological distances, as suggested by their large dispersion measures (DMs) well in excess of the Galactic values, and hence FRBs are a promising probe to study cosmology and the intergalactic medium (IGM).…”

“…Many theoretical models have been proposed to this end, and we refer to e.g. [6][7][8][9][10][11][12][13] for comprehensive reviews and [16] for the up-to-date online catalogue of FRB theories. On the other hand, the observational data were rapidly accumulated in the recent years [10-14, 17, 18].…”

“…Similarly, our second motivation is related to FRBs associated with young or old populations. For a long time, it was speculated that the FRB distribution tracks the cosmic star formation history (SFH) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The landmark Galactic FRB 200428 associated with the young magnetar SGR 1935+2154 [36][37][38][39] confirmed that at least some (if not all) FRBs originate from young magnetars.…”

Simultaneous View of FRB 180301 with FAST and NICER during a Bursting Phase

“…Fast radio bursts (FRBs) are millisecond-duration radio pulses whose origin is still highly debated (Lorimer et al 2007;Tendulkar et al 2017;CHIME/FRB Collaboration et al 2019a;Petroff et al 2019;Zhang 2020;Caleb & Keane 2021;Sridhar et al 2021). Recently, large radio surveys have detected several new FRBs, some of which have shown repeating emission, implying an origin that does not involve one-time cataclysmic events, such as neutron star mergers (CHIME/FRB Collaboration et al 2019a).…”

A MeerKAT, e-MERLIN, H.E.S.S. and Swift search for persistent and transient emission associated with three localised FRBs

“…Lorimer et al 2007;Thornton et al 2013;Macquart et al 2020). The estimated high radio luminosities and associated brightness temperatures required to produce these shorttimescale energetic events at such distances are what makes them intriguing (Petroff et al 2021;Caleb & Keane 2021). They have been observed to emit from ∼ 110 MHz − 8 GHz, though not yet across a wide and continuous frequency band due to the variable bandlimited spectra of the single pulses.…”