Magnetic Penrose process in the magnetized Kerr spacetime

Abstract

Magnetic Penrose process (MPP) could be highly efficient (efficiency can even exceed $100\%$) for extracting the energy from a Kerr black hole, if it is immersed in a mG order magnetic field. Considering the exact solution of the magnetized Kerr spacetime, here we derive the exact expression of efficiency (${\eta }_{\mathrm{MPP}}$) for MPP, which is valid for both the Kerr black hole (BH) as well as Kerr superspinar (SS), and also from the weak magnetic field to an ultra-strong magnetic field $(B)$ which can even distort the original Kerr geometry. We show that although the value of ${\eta }_{\mathrm{MPP}}$ increases upto a certain value of ultra-strong magnetic field ($B_p$), it decreases to zero for $B>B_p$, in case of the Kerr BHs. On the other hand, ${\eta }_{\mathrm{MPP}}$ shows the opposite behavior in case of the Kerr SSs. One intriguing feature that emerges is, ${\eta }_{\mathrm{MPP}}$ acquires the maximum value for the Kerr parameter $a_{\ast }\approx 0.786$ (unlike $a_{\ast }=1$ for the ordinary PP), decreases for $0.786<a_{\ast }\le 1$. This indicates that the BH starts to expel the effect of magnetic field for $a_{\ast }>0.786$, and is fully expelled from the extremal Kerr BH due to the gravitational Meissner effect. As a special case of MPP, we also study the ordinary Penrose process (PP) for magnetized Kerr spacetime. We show that MPP for Kerr BHs, Kerr SSs and ordinary PP for Kerr SSs can be superefficient for the astrophysical applications to powering engines in the high-energy sources like active galactic nuclei and quasars, in the weak magnetic fields. Our strong magnetic field result of MPP could be important to the primordial BHs in the early Universe immersed in the primordial magnetic fields, and to the transmuted BHs which are formed by collapsing and/or by merging of the magnetized progenitors. It is almost impossible to extract the energy from a BH (SS) through MPP (PP) in the ultra-strong magnetic fields.

arXiv comment18 pages, 11 figures, revised version, accepted for publication in PRD, CC dedicates this paper to his mother Shree Snigdha Chakraborty

References in corpus (35)

• GW190814: Gravitational Waves from the Coalescence of a 23 M${}_{\odot }$ Black Hole with a 2.6 M${}_{\odot }$ Compact Object
• GW190425: Observation of a Compact Binary Coalescence with Total Mass $\sim 3.4M_{\odot }$
• Efficient Generation of Jets from Magnetically Arrested Accretion on a Rapidly Spinning Black Hole
• Magnetic Fields in the Early Universe
• Magnetically Arrested Disk: An Energetically Efficient Accretion Flow
• First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
• Testing the rotational nature of the supermassive object M87* from the circularity and size of its first image
• First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
• A strong magnetic field around the supermassive black hole at the centre of the Galaxy
• Apparent shape of super-spinning black holes
• Black Hole Spin Evolution
• Astrophysical Violations of the Kerr Bound as a Possible Signature of String Theory
• The distinguishing signature of Magnetic Penrose Process
• Supermassive black holes as possible sources of ultra high energy cosmic rays
• Low Mass Black Holes from Dark Core Collapse
• Intense Electromagnetic Outbursts from Collapsing Hypermassive Neutron Stars
• Magnetic Hair and Reconnection in Black Hole Magnetospheres
• Distinguishing Kerr naked singularities and black holes using the spin precession of a test gyro in strong gravitational fields
• The magnetic field in the X-ray corona of Cygnus X-1
• On the Nature of the Magnetic Fields Generated During the Electroweak Phase Transition
• Electromagnetic power of merging and collapsing compact objects
• Strong gravity Lense-Thirring Precession in Kerr and Kerr-Taub-NUT spacetimes
• Slowly balding black holes
• Spin precession in a black hole and naked singularity spacetimes
• Magnetised Kerr/CFT correspondence
• Motion of Charged Particles around a Weakly Magnetized Rotating Black Hole
• Escape of Charged Particles Moving around a Weakly Magnetized Kerr Black Hole
• Multimessenger signals from black hole-neutron star mergers without significant tidal disruption
• Charged Particles Circular Orbits around Weakly Charged and Magnetized Kerr Black Holes
• On the stability of a superspinar
• Energy Extraction from Spinning Black Holes via Relativistic Jets
• Gravitational analog of Faraday rotation in the magnetized Kerr and Reissner-Nordström spacetimes
• Gravitomagnetic effect in magnetized neutron stars
• Gravitational Larmor precession
• Black holes shielded by magnetic fields

Cited by in corpus (4)

• Energy extraction via magnetic reconnection in magnetized black holes
• Superradiant Instability of Magnetic Black Holes
• Penrose process in magnetized non-Kerr rotating spacetime with anomalous quadrupole moment
• Spin Precession in magnetized Kerr spacetime