Speaker
Prof.
Isao Okamoto
(National Astronomical Observatory of Japan)
Description
Making use of $3+1$ formulation of black hole electrodynamics, it is argued that the frame-dragging effect combines with unipolar induction, to sustain the double-structured magnetosphere consisting of the outer and inner domains, and high-energy activities therein. The emf's, $¥cal{E}_{¥rm out}$ and $¥cal{E}_{¥rm in}$, of a pair of unipolar induction batteries driving electric currents in the two domains are equivalent to those due to a pair of magnetized rotators spinning anti-parallelly each other with $¥Omega_{¥rm F}$ and $-(¥Omega_{¥rm H}-¥Omega_{¥rm F})$, located back-to-back at both sides of the interface S$_{¥rm N}$ at $¥omega=¥Omega_{¥rm F}$ in-between, where $¥Omega_{¥rm F}$, $¥Omega_{¥rm H}$ and $¥omega$ are the angular velocities of field lines, the Kerr hole and the frame dragging due to the hole's spin. The difference, $¥cal{E}_{¥rm out}-¥cal{E}_{¥rm in}$$=¥Delta V=- (¥Omega_{¥rm H}/2¥pi c)¥Delta¥Psi$, corresponding to the difference of the two angular velocities of hypothetical rotators at S$_{¥rm N}$, $¥Omega_{¥rm F}-[-(¥Omega_{¥rm H}-¥Omega_{¥rm F}])=¥Omega_{¥rm H}$, will provide a voltage drop strong enough to develop a magnetized gap in which pair-creation discharges will take place to provide copious charged particles to out- and in-flows in both domains and allow field lines pinned down to fix $¥Omega_{¥rm F}$ with the local frame-dragging angular velocity, i.e., $¥Omega_{¥rm F}=¥omega_{¥rm N}$. Such a situation will allow one to present the hole's double structure in terms of a twin-pulsar model, consisting of a pulsar-type wind flowing toward infinity and an anti-pulsar-type wind flowing in toward the horizon, with the common particle/current sources where field lines are pinned down
(see I.¥ Okamoto, PASJ, 2015)
Author
Prof.
Isao Okamoto
(National Astronomical Observatory of Japan)
