A survey of FRB fields: Limits on repeatability

TL;DR

This survey of eight known FRB fields found no evidence of repeatability within certain periods, setting constraints on potential repeating sources and highlighting the need for longer-term observations with advanced detectors.

Contribution

The paper provides the first systematic search for repeating pulses in FRB fields and establishes upper limits on repetition periods, informing models of FRB progenitors.

Findings

No repeat pulses detected in the surveyed FRB fields.

Ruled out periodic repeaters with periods ≤ 8.6 hours.

Set limits on repeatability for periods between 8.6 and 21 hours.

Abstract

Several theories exist to explain the source of the bright, millisecond duration pulses known as fast radio bursts (FRBs). If the progenitors of FRBs are non-cataclysmic, such as giant pulses from pulsars, pulsar-planet binaries, or magnetar flares, FRB emission may be seen to repeat. We have undertaken a survey of the fields of eight known FRBs from the High Time Resolution Universe survey to search for repeating pulses. Although no repeat pulses were detected the survey yielded the detection of a new FRB, described in Petroff et al. (2015a). From our observations we rule out periodic repeating sources with periods P $\leq$ 8.6 hours and rule out sources with periods 8.6 < P < 21 hours at the 90% confidence level. At P $\geq$ 21 hours our limits fall off as ~1/P. Dedicated and persistent observations of FRB source fields are needed to rule out repetition on longer timescales, a task well-suited to next generation wide-field transient detectors.