14:00, Observatory Lab
Abstract:
We explore the analogy between a rotating magnetized black
hole and an axisymmetric pulsar and derive its electromagnetic spindown
after its formation in the core collapse of a supermassive star. The
spindown shows two characteristic phases, an early Blandford-Znajek
phase that lasts a few hundred seconds, and a late pulsar-like afterglow
phase that lasts much longer. During the first phase, the spindown
luminosity decreases almost exponentially, whereas during the afterglow
phase it decreases as t^-a with 1<a<1.5. We associate our findings
with long duration gamma-ray bursts (GRB) and compare with
observations.
DOWNLOADS