Continued radio observations of the persistent radio source associated with FRB20190520B provides insights into its origin

Abstract: Follow-up studies of persistent emission from Fast Radio Burst (FRB) sources are critical for understanding their elusive emission mechanisms and the nature of their progenitors. This work presents new observations of the persistent radio source (PRS) associated with \ourfrb. We observe a gradual decay in the PRS brightness, which is punctuated by periods of brightening and dimming at both 1.5 GHz and 3 GHz. Furthermore, our low-frequency ($<1$ GHz) observations-the first for this source-reveal evidence of a spectral break which can be attributed to absorption processes. Interpreted within the framework of the magnetar wind nebula model, our data constrain the age of the magnetar progenitor to $53^{+17}_{-10}$ years, broadly consistent with previous work. Assuming the observed 1.5 GHz variability is driven by scintillation, we derive a conservative lower limit for the source's radius of $>0.52$ pc, for a screen at 10 kpc. The observations presented here challenge the predictions of the previously published best-fit hypernebula model for this source.