GRB/HN from Kerr Black Holes in Binaries

TL;DR

This paper proposes a binary evolution model that explains the formation of Kerr black holes with high spin, providing a mechanism for long and subluminous gamma-ray bursts through the Blandford-Znajek process.

Contribution

It introduces a binary evolution framework to form rapidly spinning Kerr black holes, linking pre-collapse orbits to GRB and hypernova phenomena.

Findings

Model accounts for both long and subluminous GRB populations.

Binary evolution can produce rapidly spinning Kerr black holes.

Energy estimates support the Blandford-Znajek mechanism as a GRB source.

Abstract

The Collapsar model, in which a massive star (greater than 20 solar masses) fails to produce a SN and forms a BH, provides the main framework for understanding long Gamma-Ray Bursts (GRB) and the accompanying hypernovae (HN). However, single massive-star models that explain the population of pulsars, predict cores that rotate too slowly to produce GRBs/HNe. We present a model of binary evolution that allows the formation of Kerr black holes (BH) where the spin of the BH can be estimated from the pre-collapse orbit, and use the Blandford-Znajek (BZ) mechanism to estimate the available energy for a GRB/HN. A population synthesis study shows that this model can account for both, the long GRB and the subluminous GRB populations.