The morphology of the X-ray afterglows and of the jetted GeV emission in long GRBs
Abstract
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 ~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 $L_{\rm GeV} = A_{\rm GeV}\, t^{-\alpha _{\rm GeV}}$, observed only in some cases; and (3) a new NS (νNS), born from the SN, originating from the X-ray afterglow with $L_\mathrm{ X} = A_{\rm X}\, t^{-\alpha _{\rm X}}$, 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) AX, αX = 1.48 ± 0.32, and (3) the νNS spin time evolution. We infer (i) AGeV, αGeV = 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 ≈60° from the normal to the orbital plane. We deduce BH masses of 2.3-8.9 M⊙ 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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2021
- DOI:
- 10.1093/mnras/stab724
- arXiv:
- arXiv:2103.09142
- Bibcode:
- 2021MNRAS.504.5301R
- Keywords:
-
- black hole physics;
- binaries: general;
- gamma-ray bursts;
- transients: supernovae;
- Astrophysics - High Energy Astrophysical Phenomena;
- General Relativity and Quantum Cosmology
- E-Print:
- Accepted for publication by MNRAS on March 5, 2021