Searching for the radio remnants of short-duration gamma-ray bursts. Issue 2 (23rd October 2020)

• Record Type: Journal Article
• Authors: Ricci, R; Troja, E; Bruni, G; Matsumoto, T; Piro, L; O'Connor, B; Piran, T; Navaieelavasani, N; Corsi, A; Giacomazzo, B; Wieringa, M H
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 500:Issue 2(2021)
• Page Start: 1708
• Page End: 1720
• Publication Date: 2020-10-23
• Subjects: gamma-ray burst: general -- stars: magnetars -- stars: neutron; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa3241
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Neutron star mergers produce a substantial amount of fast-moving ejecta, expanding outwardly for years after the merger. The interaction of these ejecta with the surrounding medium may produce a weak isotropic radio remnant, detectable in relatively nearby events. We use late-time radio observations of short duration gamma-ray bursts (sGRBs) to constrain this model. Two samples of events were studied: four sGRBs that are possibly in the local (<200 Mpc) Universe were selected to constrain the remnant non-thermal emission from the sub-relativistic ejecta, whereas 17 sGRBs at cosmological distances were used to constrain the presence of a proto-magnetar central engine, possibly re-energizing the merger ejecta. We consider the case of GRB 170817A/GW170817 and find that in this case the early radio emission may be quenched by the jet blast-wave. In all cases, for ejecta mass range of ${M}_{\rm {ej}}\lesssim 10^{-2}\, (5\times 10^{-2})\, \mathrm{M}_\odot$, we can rule out very energetic merger ejecta ${E}_{\rm {ej}}\gtrsim 5\times 10^{52}\, (10^{53})\, \rm erg$, thus excluding the presence of a powerful magnetar as a merger remnant.