A fast radio burst with a low dispersion measure

TL;DR

This paper reports the discovery of a low-dispersion measure fast radio burst (FRB) with high fluence, highlighting the importance of beam pattern modeling for future FRB detections in sidelobes.

Contribution

It presents a new FRB detection with the lowest dispersion measure and discusses its potential origin in sidelobes, emphasizing the significance of beam pattern analysis.

Findings

FRB 110214 has one of the lowest DMs among known FRBs.

The burst's intrinsic fluence could be as high as 2000 Jy ms.

No repeat pulses were observed in 100 hours of follow-up.

Abstract

Fast radio bursts (FRBs) are millisecond pulses of radio emission of seemingly extragalactic origin. More than 50 FRBs have now been detected, with only one seen to repeat. Here we present a new FRB discovery, FRB 110214, which was detected in the high latitude portion of the High Time Resolution Universe South survey at the Parkes telescope. FRB 110214 has one of the lowest dispersion measures of any known FRB (DM = 168.9$\pm$0.5 pc cm$^{-3}$), and was detected in two beams of the Parkes multi-beam receiver. A triangulation of the burst origin on the sky identified three possible regions in the beam pattern where it may have originated, all in sidelobes of the primary detection beam. Depending on the true location of the burst the intrinsic fluence is estimated to fall in the range of 50 -- 2000 Jy ms, making FRB 110214 one of the highest-fluence FRBs detected with the Parkes telescope. No repeating pulses were seen in almost 100 hours of follow-up observations with the Parkes telescope down to a limiting fluence of 0.3 Jy ms for a 2-ms pulse. Similar low-DM, ultra-bright FRBs may be detected in telescope sidelobes in the future, making careful modeling of multi-beam instrument beam patterns of utmost importance for upcoming FRB surveys.