Origin of $10^{15}-10^{16}$G Magnetic Fields in the Central Engine of Gamma Ray Bursts

摘要

Various authors have suggested that the gamma-ray burst (GRB) central engineis a rapidly rotating, strongly magnetized, $(\sim 10^{15}-10^{16}$ G) compactobject. The strong magnetic field can accelerate and collimate the relativisticflow and the rotation of the compact object can be the energy source of theGRB. The major problem in this scenario is the difficulty of finding anastrophysical mechanism for obtaining such intense fields. Whereas, inprinciple, a neutron star could maintain such strong fields, it is difficult tojustify a scenario for their creation. If the compact object is a black hole,the problem is more difficult since, according to general relativity it has "nohair" (i.e., no magnetic field). Schuster, Blackett, Pauli, and others havesuggested that a rotating neutral body can create a magnetic field bynon-minimal gravitational-electromagnetic coupling (NMGEC). TheSchuster-Blackett form of NMGEC was obtained from the Mikhail and Wanas'stetrad theory of gravitation (MW). We call the general theory NMGEC-MW. We investigate here the possible origin of the intense magnetic fields $\sim10^{15}-10^{16}$ G in GRBs by NMGEC-MW. Whereas these fields are difficult toexplain astrophysically, we find that they are easily explained by NMGEC-MW. Itnot only explains the origin of the $\sim 10^{15}-10^{16}$G fields when thecompact object is a neutron star, but also when it is a black hole.