Beltrami state in black-hole accretion disk: A magnetofluid approach

Abstract

Using the magnetofluid unification framework, we show that the accretion disk plasma (embedded in the background geometry of a blackhole) can relax to a class of states known as the Beltrami-Bernoulli (BB) equilibria. Modeling the disk plasma as a Hall MHD system, we find that the space-time curvature can significantly alter the magnetic/velocity decay rate as we move away from the compact object; the velocity profiles in BB states, for example, deviate substantially from the predicted corresponding geodesic velocity profiles. These departures imply a rich interplay of plasma dynamics and general relativity revealed by examining the corresponding Bernoulli condition representing "homogeneity" of total energy. The relaxed states have their origin in the constraints provided by the two helicity invariants of Hall MHD. These helicities conspire to introduce a new oscillatory length scale into the system that is strongly influenced by relativistic and thermal effects.

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References in corpus (9)

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Cited by in corpus (5)

• On the Relaxed States in the Mixture of Degenerate and Non-Degenerate Hot Plasmas of Astrophysical Objects
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• Macro-scale fast flow and magnetic field generation in 2-temperature relativistic electron-ion plasmas of astrophysical objects
• On the quadruple Beltrami fields in thermally relativistic electron-positron-ion plasma
• Relaxation of a Two Electron-Temperature Relativistic Hot Electron-Positron-Ion Plasma