GB5 - GRBs and the Afterglow |
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Speaker |
Becerra Bayona, Laura |
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Coauthors |
Cipolletta , Federico; Fryer, Chris L.; Rueda, , Jorge A.;Ruffini, Remo |
| Talk Title |
Angular momentum role in the Hypercritical accretion of Binary-Driven Hypernovae |
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Abstract |
The induced gravitational collapse (IGC) paradigm explains a class of energetic, long-duration gamma-ray bursts associated with Ic supernovae, recently named binary-driven hypernovae. The progenitor is a tight binary system formed of a carbon-oxygen core and a neutron star companion (NS). The supernova ejecta triggers a hypercritical accretion process onto the NS, which reaches in a few seconds the critical mass, and gravitationally collapses to a black hole emitting a GRB. In our previous simulations of this process we adopted a spherically symmetric approximation to compute the features of the hypercritical accretion process. We here present the first estimates of the angular momentum transported by the supernova ejecta, and perform numerical simulations of the angular momentum transfer to the NS during the hyperaccretion process in full general relativity. We show that the NS: i)reaches in a few seconds either mass-shedding limit or the secular axisymmetric instability depending on its initial mass; ii) reaches a maximum dimensionless angular momentum value, [cJ/(GM^2)]_max ≈ 0.7; iii) can support less angular momentum than the one transported by supernova ejecta, hence there is an angular momentum excess which necessarily leads to jetted emission. |
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