Fast radio bursts

Abstract

The discovery of radio pulsars over a half century ago was a seminal moment in astronomy. It demonstrated the existence of neutron stars, gave a powerful observational tool to study them, and has allowed us to probe strong gravity, dense matter, and the interstellar medium. More recently, pulsar surveys have led to the serendipitous discovery of fast radio bursts (FRBs). While FRBs appear similar to the individual pulses from pulsars, their large dispersive delays suggest that they originate from far outside the Milky Way and hence are many ordersof-magnitude more luminous. While most FRBs appear to be one-off, perhaps cataclysmic events, two sources are now known to repeat and thus clearly have a longer-lived central engine. Beyond understanding how they are created, there is also the prospect of using FRBs -as with pulsars -to probe the extremes of the Universe as well as the otherwise invisible intervening medium. Such studies will be aided by the high implied all-sky event rate: there is a detectable FRB roughly once every minute occurring somewhere on the sky. The fact that less than a hundred FRB sources have been discovered in the last decade is largely due to the small fields-of-view of current radio telescopes. A new generation of wide-field instruments is now coming online, however, and these will be capable of detecting multiple FRBs per day. We are thus on the brink of further breakthroughs in the short-duration radio transient phase space, which will be critical for differentiating between the many proposed theories for the origin of FRBs. In this review, we give an observational and theoretical introduction at a level that is accessible to astronomers entering the field.

Young magnetars with fracturing crusts as fast radio burst repeaters

“…Other mechanisms have been proposed [see e.g. Beloborodov (2017)], which are also consistent with a quake picture (Petroff et al 2019).…”

The Fast Radio Burst Luminosity Function and Death Line in the Low-twist Magnetar Model

“…Observational rate studies (cf. Table 3 in Petroff et al 2019) estimate an all-sky rate of order ∼ 10 3 − 10 4 FRBs per day above a few Jy ms fluence threshold, corresponding to a level of about Φ ∼ 10 −16 − 10 −17 erg cm −2 for standard assumptions on bandwidth and flat FRB spectral index. As apparent in Figure 3, we predict that future enhancements in sensitivity may result in up to O(10 2 − 10 4 ) factor increase in FRB rate over current limits for α = 1, while a more modest O(10 1 − 10 2 ) factor for α = −1.…”

Magnetars from Neutron Star–White Dwarf Mergers: Application to Fast Radio Bursts

“…Fast radio bursts (FRBs) have remained an extragalactic enigma so far (Katz 2018;Popov et al 2018;Petroff et al 2019;Cordes & Chatterjee 2019) since they were discovered by Lorimer et al (2007), Keane et al (2012), and Thornton et al (2013). They are millisecond-duration coherent radio pulses with average upper limits of the peak luminosity L p ∼ 1 × 10 42 − 8 × 10 44 erg s −1 and energy E ∼ 7 × 10 39 − 2 × 10 42 erg (Zhang 2018), characterized by a single peak mainly or multiple peaks rarely (Champion et al 2016;Farah et al 2018;Prochaska et al 2019), phenomenally divided into repeating bursts (Spitler et al 2016;CHIME/FRB Collaboration et al 2019a,b;Kumar et al 2019;CHIME/FRB Collaboration et al 2020) and non-repeating bursts.…”