Black hole electrodynamics: How does unipolar induction work in Kerr black holes?

Publications of the Astronomical Society of Japan

Okamoto, Isao¹ 

[1] National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588, Japan and Institute for Black Hole Mining, 114-6 Ochikawa, Hino-shi, Tokyo 191-0034, Japan

关键词: "ISM: magnetic fields";    MHD;    "stars: winds;    outflows";   

DOI  :  10.1093/pasj/psv056

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Itisarguedthatthroughmagnetohydrodynamiccouplingswiththefield-lineangularvelocity/thecross-fieldpotentialgradientΩF,theframe-draggingangularvelocityωacquiresanewroleofthegravito-electricpotentialgradient,whichproducesthealong-fieldgradientofthepotentialgradient.Withuseofthefield-lineangularvelocity,ΩFω≡ΩF−ω,measuredbyfiducialobserverslivingin“absolutespace”circulatingwithω,itisthenshownthatthehole'sspinrateΩHalsohasanothersideofthealong-fielddifferenceofthepotentialgradientbetweenthesurface-at-infinityS∞andthehorizonsurfaceSH,i.e.,ΩH = ΔΩFω≡(ΩFω)∞−(ΩFω)H,whichgivesrisetoavoltagedropΔV ∝ ΔΩFω = ΩHattheinterfaceSNwith(ΩFω)N = 0betweentheouterandinnerforce-freedomains,leadingtoformationofamagnetizedgapunderSN.TheEMFsduetoapairofunipolarinductionbatteries,$${calE}_{mout}$$and$${calE}_{min}$$,drivecurrentstoapairofcircuitsinthetwodomains,andsatisfyrelation$${calE}_{mout}-{calE}_{min}=DeltaV$$.TheeigenvalueΩFisdeterminedbythecriticality-boundaryconditioninMHDwindtheoryintermsofΩH,i.e.,≈ (1/2)ΩH.Thepresentgapmodelwithapairofbatteriesandastrongvoltagedropisfundamentallydifferentfromanyexistingpulsargapmodels.

【 授权许可】

Unknown