The morphology of the X-ray afterglows and of the jetted GeV emission in long GRBs

We recall evidence that long gamma-ray bursts (GRBs) have binary progenitors and give new examples. Binary-driven hypernovae (BdHNe) consist of a carbon-oxygen core (COcore) and a neutron star (NS) companion. For binary periods similar to 5 min, the COcore collapse originates the subclass BdHN I characterized by (1) an outstanding supernova (SN; the 'SN-rise'); (2) a black hole (BH), born from the NS collapse by SN matter accretion, leading to a GeV emission with luminosity L-GeV = A(GeV) t(-alpha GeV), observed only in some cases; and (3) a new NS (nu NS), born from the SN, originating from the X-ray afterglow with L-X = A(X) t(-alpha X), observed in all BdHN I. We record 378 sources and present for four prototype GRBs 130427A, 160509A, 180720B, and 190114C: (1) spectra, luminosities, SN-rise duration; (2) A(GeV), alpha(GeV) = 1.48 +/- 0.32, and (3) the vNS spin time evolution. We infer (i) A(GeV), alpha(GeV) = 1.19 +/- 0.04 and (ii) the BdHN I morphology from time-resolved spectral analysis, three-dimensional simulations, and the GeV emission presence/absence in 54 sources within the Fermi-Large Area Telescope boresight angle. For 25 sources, we give the integrated and time-varying GeV emission, 29 sources have no GeV emission detected and show X/gamma-ray flares previously inferred as observed along the binary plane. The 25/54 ratio implies the GeV radiation is emitted within a cone of half-opening angle approximate to 60 degrees from the normal to the orbital plane. We deduce BH masses of 2.3-8.9 M-circle dot and spin of 0.27-0.87 by explaining the GeV emission from the BH rotational energy extraction, while their time evolution validates the BH mass-energy formula.

Automated summary

The study suggests that long gamma-ray bursts (GRBs) have binary progenitors, with new examples showing a binary-driven hypernova consisting of a carbon-oxygen core and a neutron star companion. Spectral analysis of prototype GRBs provides insights into the characteristics and evolution of supernovae, GeV emissions, black hole masses, and their rotational energy extraction. The findings indicate the presence of GeV radiation emitted within a cone from the orbital plane and validate the BH mass-energy formula through time evolution analysis.