Angular Momentum Role in the Hypercritical Accretion of Binary-driven Hypernovae
Abstract
The induced gravitational collapse paradigm explains a class of energetic, {E}{{iso}}≳ {10}52 erg, long-duration gamma-ray bursts (GRBs) associated with Ic supernovae, recently named binary-driven hypernovae. The progenitor is a tight binary system formed of a carbon-oxygen (CO) core and a neutron star (NS) companion. The supernova ejecta of the exploding CO core trigger a hypercritical accretion process onto the NS, which reaches the critical mass in a few seconds, 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, {L}{{acc}}, 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 (1) reaches either the mass-shedding limit or the secular axisymmetric instability in a few seconds depending on its initial mass, (2) reaches a maximum dimensionless angular momentum value, {[{cJ}/({{GM}}2)]}{{max}}≈ 0.7, and (3) can support less angular momentum than the one transported by supernova ejecta, {L}{{acc}}\gt {J}{{NS,max}}, hence there is an angular momentum excess that necessarily leads to jetted emission.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2015
- DOI:
- 10.1088/0004-637X/812/2/100
- arXiv:
- arXiv:1505.07580
- Bibcode:
- 2015ApJ...812..100B
- Keywords:
-
- gamma-ray burst: general;
- Astrophysics - High Energy Astrophysical Phenomena;
- General Relativity and Quantum Cosmology;
- Nuclear Theory
- E-Print:
- Accepted for publication in Astrophysical Journal