The Progenitor and Central Engine of short-duration GRB 201006A associated with a coherent radio flash

TL;DR

This paper investigates the origin of a coherent radio flash associated with short GRB 201006A, proposing it originates from a supramassive magnetar collapsing into a black hole, supported by data reanalysis and theoretical modeling.

Contribution

It introduces the hypothesis that the radio flash is due to a supramassive magnetar central engine, providing detailed modeling and analysis to support this scenario.

Findings

Radio flash consistent with magnetar collapse hypothesis

Magnetar parameters fall within reasonable physical ranges

Supports merger origin from compact star binaries

Abstract

Recently, the detection of a coherent radio flash associated with short-duration GRB 201006A, occurring 76.6 minutes after the burst, has attracted great attention. However, the physical origin of the coherent radio flash remains under debate. By reanalyzing its data observed by Fermi and Swift, we find that an early radio afterglow as the physical origin of the radio flash can be ruled out, but the coherent radio emission seems to be consistent with the hypothesis of a supramassive magnetar as the central engine collapsing into a black hole. Within this scenario, the derived magnetar surface magnetic field ($B_{\rm p}$) and the initial spin period ($P_{\rm 0}$) fall into a reasonable range but require a preferable low value of $\eta_{\rm R} = 10^{-7}$ or $10^{-6}$. Moreover, the calculated low-$\varepsilon$ value and $E_{\rm \gamma,iso}-E_{\rm p}$ correlation of GRB 201006A also supports the progenitor which is from the merger of compact stars. We also discuss the non-detected kilonova emission associated with GRB 201006A, and then compare with its upper limits of optical observations.