2020/08/31 by R. Ricci, Roberto Ricci, E. Troja +16 · 2 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Ejecta #Gamma-ray burst #Gamma-ray bursts and supernovae #Kilonova #Magnetar #Neutron star #Physics #Pulsars and Gravitational Waves Research #Supernova #astro-ph.HE
paper · pdf · doi:10.1093/mnras/staa3241
13 pages, 8 figures, 3 tables. Accepted for pubblication in MNRAS
arxiv created 2020/10/21 · openalex publication_date 2020/10/21 · arxiv updated 2020/10/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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× 10-2) M_\odot, we can rule out very energetic merger ejecta E_\rm ej\gtrsim 5× 1052 (1053) \rm erg, thus excluding the presence of a powerful magnetar as a merger remnant.