相关论文: Highly-collimated, magnetically-dominated jets aro…
A toy model for magnetic extraction of energy from black hole (BH) accretion disk is discussed by considering the restriction of the screw instability to the magnetic field configuration. Three mechanisms of extracting energy magnetically…
We have performed 3-D numerical magnetohydrodynamic (MHD) jet experiments to study the instabilities associated with strongly toroidal magnetic fields and determine if such magnetic configurations in jets are as unstable as similar…
We re-examine the possibility that astrophysical jet collimation may arise from the geometry of rotating black holes and the presence of high-energy particles resulting from a Penrose process, without the help of magnetic fields. Our…
Analytical studies have raised the concern that a mysterious expulsion of magnetic field lines by a rapidly-spinning black hole (dubbed the black hole Meissner effect) would shut down the Blandford-Znajek process and quench the jets of…
The Blandford-Znajek monopole is a conjectured solution of force-free electrodynamics in the vicinity of a slowly rotating Kerr black hole, supposedly defined as a perturbation in small angular momentum. It is used to argue for the…
We present a new, semi-analytic formalism to model the acceleration and collimation of relativistic jets in a gravitational potential. The gravitational energy density includes the kinetic, thermal, and electromagnetic mass contributions.…
We calculate the evolution of the prompt intrinsic Poynting power generated by merging black holes. Orbiting black holes induce rotation of the space-time. In a presence of magnetic field supported by an accretion disk outside of the orbit,…
In this paper we consider stability of magnetized jets that carry no net electric current and do not have current sheets (Gourgouliatos et al. 2012). The non-relativistic MHD equations are linearized around the background velocity and the…
We investigate the extraction of the rotational energy of a black hole under different accreting environment. When the accretion rate is moderate, the accretion disk consists of an outer thin disk and an inner advection-dominated accretion…
The Blandford-Znajek (BZ) mechanism describes a physical process for the energy extraction from a spinning black hole (BH), which is believed to power a great variety of astrophysical sources, such as active galactic nuclei (AGNs) and Gamma…
The collimation of a Poynting-flux dominated jet by a wind emanating from the surface of an accretion flow is computed using a semi-analytic model. The injection of the disk wind is treated as a boundary condition in the equatorial plane,…
Kinematical and luminosity relations for black-hole jet sources are reviewed. If the TeV flares observed from PKS 2155-304 in 2006 July are assumed to originate from a black hole with mass $\approx 10^8 M_8 M_\odot$, then the $\sim 5$…
We present the results of nine simulations of radiatively-inefficient magnetically arrested disks (MADs) across different values of the black hole spin parameter $a_*$: $-0.9$, $-0.7$, $-0.5$, $-0.3$, 0, 0.3, 0.5, 0.7, and 0.9. Each…
We investigate the correlation between 151 MHz radio luminosity, L_151MHz, and jet power, P_jet, for a sample of low-power radio galaxies, of which the jet power is estimated from X-ray cavities. The jet power for a sample of FR I radio…
We analyse flows around a rotating black hole and obtain self-consistent accretion-ejection solutions in full general relativistic prescription. Entire energy-angular momentum parameter space is investigated in the advective regime to…
The study of Magnetically Arrested Disks (MAD) attract strong interest in recent years, as these disk configurations were found to generate strong jets as observed in many accreting systems. Here, we present the results of 14 general…
The magnetic flux distribution is determined by the solution of the Grad-Shafranov equation. With differential rotation, i.e. the variation of the iso-rotation parameter, the shape of the light surface must be calculated in an iterative…
The large number of isolated black holes (IBHs) in the Galaxy, estimated to be 10^8, implies a very high density of 10^-4 pc^-3 and an average distance between IBHs of 10 pc. Our study shows that the magnetic flux, accumulated on the…
We present new developments of the simple model of the central engine of GRB, proposed recently. The model is based on minimal assumptions: some rotating compact relativistic object at the center and stable perturbations of its rotating…
We propose a scenario for launching relativistic jets from rotating black holes, in which small-scale magnetic flux loops, sustained by disc turbulence, are forced to inflate and open by differential rotation between the black hole and the…