Scattering variability detected from the circumsource medium of FRB 20190520B

Abstract

Fast radio bursts (FRBs) are millisecond-timescale radio transients, the origins of which are predominantly extragalactic and likely involve highly magnetized compact objects. FRBs undergo multipath propagation, or scattering, from electron density fluctuations on sub-parsec scales in ionized gas along the line-of-sight. Scattering observations have located plasma structures within FRB host galaxies, probed Galactic and extragalactic turbulence, and constrained FRB redshifts. Scattering also inhibits FRB detection and biases the observed FRB population. We report the detection of scattering times from the repeating FRB 20190520B that vary by up to a factor of two or more on minutes to days-long timescales. In one notable case, the scattering time varied from $7.9\pm 0.4$ ms to less than 3.1 ms ($95\%$ confidence) over 2.9 minutes at 1.45 GHz. The scattering times appear to be uncorrelated between bursts or with dispersion and rotation measure variations. Scattering variations are attributable to dynamic, inhomogeneous plasma in the circumsource medium, and analogous variations have been observed from the Crab pulsar. Under such circumstances, the frequency dependence of scattering can deviate from the typical power-law used to measure scattering. Similar variations may therefore be detectable from other FRBs, even those with inconspicuous scattering, providing a unique probe of small-scale processes within FRB environments.

10 pages, 9 figures, accepted to MNRAS

References in corpus (8)

• The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project
• A repeating fast radio burst associated with a persistent radio source
• A bimodal burst energy distribution of a repeating fast radio burst source
• The observed velocity distribution of young pulsars
• Frequency-dependent polarization of repeating fast radio bursts-implications for their origin
• The Large Dispersion and Scattering of FRB 20190520B are Dominated by the Host Galaxy
• Faraday depolarization and induced circular polarization by multi-path propagation with application to FRBs
• Kinematics of Crab Giant Pulses

Cited by in corpus (12)

• CHIME/FRB Discovery of 25 Repeating Fast Radio Burst Sources
• Detection of ultra-fast radio bursts from FRB 20121102A
• The FRB20190520B Sightline Intersects Foreground Galaxy Clusters
• Deep Synoptic Array science: Two fast radio burst sources in massive galaxy clusters
• Modelling Annual Scintillation Velocity Variations of FRB 20201124A
• A Persistently Active Fast Radio Burst source Embedded in an Expanding Supernova Remnant
• A narrowband burst from FRB 20190520B simultaneously observed by FAST and Parkes
• Scintillometry of Fast Radio Bursts: Resolution effects in two-screen models
• The Extreme Faraday Effect in Fast Radio Bursts
• A Generic Model for Persistent Radio Source around Fast Radio Bursts
• Flux Variations of Fast Radio Bursts and Their Persistent Radio Sources: Evidence for a Shared Progenitor
• The EMPI Code for Plasma-Induced Effects on Radio Waves I: Non-Magnetized Media and Applications to Fast Radio Bursts