TP-01

Gamma ray bursts powered by Blandford-Znajek mechanism

Hyun Kyu Lee

We investigate the possibilty that gamma-ray bursts are powered by a central engine consisting of a black hole with an external magnetic field supported by a surrounding disk or torus. The rotational energy of the black hole can be extracted electromatically as a Poynting flux, a mechanism proposed by Blandford and Znajek(1977). Several issues on the Blandford-Znajek mechanism including the possible constraints from the accretion disk and MHD flows onto the black hole will be discussed.