相关论文: Issues in the Blandford-Znajek Process for GRB Inn…

The rotational energy of a black hole can be extracted via the Blandford-Znajek mechanism and numerical simulations suggest a strong dependence of the power of the produced jet on the black hole spin. A recent study has found no evidence…

The launching of astrophysical jets provides the most compelling observational evidence for direct extraction of black hole (BH) spin energy via the Blandford-Znajek (BZ) mechanism. Whilst it is known that spinning Kerr BHs within general…

Hyperaccreting stellar-mass black hole systems are leading candidates for the central engines of gamma-ray bursts (GRBs). Their jets are thought to be powered by either the Blandford-Znajek (BZ) process or neutrino-dominated accretion flows…

In association with the Blanford-Znajek mechanism for rotational energy extraction from Kerr black holes, it is of some interest to explore how much of magnetic flux can actually penetrate the horizon at least in idealized situations. For…

We explore the connection between black hole spin and AGN power by addressing the consequences underlying the assumption in the recent literature that the gap region between accretion disks and black holes is fundamental in producing…

`Internal plateau' followed by a sharp decay is commonly seen in short gamma-ray burst (GRB) light curves. The plateau component is usually interpreted as the dipole emission from a supra-massive magnetar, and the sharp decay may imply the…

Magnetic fields connecting the immediate environs of rotating black holes to large distances appear to be the most promising mechanism for launching relativistic jets, an idea first developed by Blandford and Znajek in the mid-1970s. To…

Despite their potential importance for understanding astrophysical jets, physically realistic exact solutions for magnetospheres around Kerr black holes have not been found, even in the force-free approximation. Instead approximate…

A toy model for gamma-ray burst supernovae (GRB-SNe) is discussed by considering the effects of screw instability of magnetic field in black hole (BH) magnetosphere. The screw instability in the Blandford-Znajek (BZ) process (henceforth…

We suggest that an extreme Kerr black hole with a mass $\sim 10^6M_\odot$, a dimensionless angular momentum $A\sim 1$ and a marginal stable orbital radius $r_{ms}\sim 3r_s\sim 10^{12}M_6 cm$ located in a normal galaxy, may produced a…

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,…

A toy model for gamma-ray burst-supernovae (GRB-SN) is discussed by considering the coexistence of baryon poor outflows from black holes (BHs) and a powerful spin-connection to surrounding disk, giving rise to consistent calorimetry as…

These lectures provide a detailed introduction to the electro- dynamics of black holes. A simplified derivation of the basic membrane equations for stationary, axisymmetric black holes is given. The general theory is applied to idealized…

Magnetic fields play a central role in black hole astrophysics, powering relativistic jets and other energetic phenomena. While near-horizon magnetic field is usually assumed to originate from the accretion flow, additional large-scale…

We present simulations of thin accretion disks around black holes investigating a mean-field disk dynamo in our resistive GRMHD code (Vourellis et al. 2019) that is able to produce a large scale magnetic flux. We consider a weak seed field…

We calculate the advection/diffusion of the large-scale magnetic field threading an ADAF, and find that the magnetic field can be dragged inward by the accretion flow efficiently, if the magnetic Prandtl number P~1. This is due to the large…

We propose a two-component jet model consistent with the observations of several gamma ray bursts (GRBs) and active galactic nuclei (AGNs). The jet consists of inner and outer components, and they are supposed to be driven by the…

The neutrino-cooled accretion disk, which was proposed to work as the central engine of gamma-ray bursts, encounters difficulty in interpreting the X-ray flares after the prompt gamma-ray emission. In this paper, the magnetic coupling…

In this paper we report the results of axisymmetric relativistic MHD simulations for the problem of Kerr black hole immersed into a rarefied plasma with ''uniform'' magnetic field. The long term solution shows properties which are…

In the Penrose process and the Blandford-Znajek mechanism, the rotational energy of a black hole (BH) is extracted via particle fission and magnetic tension, respectively. Recently, inspired by a fundamental trait in plasma astrophysics…