大样本恒星演化研究组知识库

We reinvestigate the structure of a steady axisymmetric force-free magnetosphere around a Kerr black hole (BH). The BH magnetosphere structure is governed by a second-order differential equation of A(phi) depending on two "free" functions Omega and I, where A(phi) is the phi component of the vector potential of the electromagnetic field, Omega is the angular velocity of the magnetic field lines, and I is the poloidal electric current. While the two functions Omega and I are not arbitrarily given, they do need to be self-consistently determined along with the differential equation. Based on the perturbation approach we proposed in paper I, in this paper, we self-consistently sort out two boundary conditions governing Omega and I, and interpret these conditions mathematically and physically. Making use of the boundary conditions, we prove that all magnetic field lines crossing the infinite-redshift surface also penetrate the event horizon. Furthermore, we argue that the BH Meissner effect does not work in a force-free magnetosphere due to the perfect conductivity.