On the magnetoionic environments of fast radio bursts. Issue 1 (7th September 2020)

• Record Type: Journal Article
• Authors: Wang, Wei-Yang; Zhang, Bing; Chen, Xuelei; Xu, Renxin
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 499:Issue 1(2020)
• Page Start: 355
• Page End: 361
• Publication Date: 2020-09-07
• Subjects: stars: neutron -- pulsars: general -- fast radio bursts; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa2693
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Observations of the Faraday rotation measure, combined with the dispersion measure, can be used to infer the magnetoionic environment of a radio source. We investigate the magnetoionic environments of fast radio bursts (FRBs) by deriving their estimated average magnetic field strengths along the line of sight 〈 B ∥ 〉 in their host galaxies and comparing them with those of Galactic pulsars and magnetars. We find that for those FRBs with RM measurements, the mean 〈 B ∥ 〉 are $1.77^{+9.01}_{-1.48}\, \rm \mu G$ and $1.74^{+14.82}_{-1.55}\, \rm \mu G$ using two different methods, which is slightly larger but not inconsistent with the distribution of Galactic pulsars, $1.00^{+1.51}_{-0.60}\, \rm \mu G$ . Only six Galactic magnetars have estimated 〈 B ∥ 〉. Excluding PSR J1745–2900 that has an anomalously high value due to its proximity with the Galactic Centre, the other five sources have a mean value of $1.70\, \rm \mu G$, which is statistically consistent with the 〈 B ∥ 〉 distributions of both Galactic pulsars and FRBs. There is no apparent trend of evolution of magnetar 〈 B ∥ 〉 as a function of age or surface magnetic field strength. Galactic pulsars and magnetars close to the Galactic Centre have relatively larger 〈 B ∥ 〉 values than other pulsars/magnetars. We discuss the implications of these results for the magnetoionic environments of FRB 121102 within the context of magnetar model and the model invoking a supermassive black hole, and for the origin of FRBs in general.