Related papers: Magnetic Field Upper Limits for Jet Formation
The magnetic field in an accretion disk is estimated assuming that all of the angular momentum within prescribed accretion disk radii is removed by a jet. The magnetic field estimated at the base of the jet is extrapolated to the blazar…
We investigate the dependence of the GRB jet structure and its evolution on the properties of the accreting torus in the central engine. Our models numerically evolve the accretion disk around a Kerr black hole using 3D general relativistic…
We summarise all the reported detections of, and upper limits to, the radio emission from persistent (i.e. non-transient) X-ray binaries. A striking result is a common mean observed radio luminosity from the black hole candidates (BHCs) in…
Jets provide an important channel for kinetic feedback from accreting black holes into their environment, without which models of the formation of large-scale structure in the universe fail to reproduce the observed properties of galaxies.…
M87 has been the target of numerous astronomical observations across the electromagnetic spectrum and Very Long Baseline Interferometry (VLBI) resolved an edge-brightened jet. However, the origin and formation of its jets remain unclear. In…
The idea that black hole spin is instrumental in the generation of powerful jets in active galactic nuclei and X-ray binaries is arguably the most contentious claim in black hole astrophysics. Because jets are thought to originate in the…
Observations of jets from quasars and other types of accreting black hole are briefly summarized. The importance of beaming and $\gamma$-ray observations for understanding the origin of these jets is emphasised. It is argued that both the…
We estimated the magnetic field strength at the horizon radius of black holes, that is derived by the magnetic coupling process and depended on the black hole mass $M_{BH}$ and the accretion rate $\dot{M}$. Our estimation is based on the…
The power of jets from black holes are expected to depend on both the spin of the black hole and the structure of the accretion disk in the region of the last stable orbit. We investigate these dependencies using two different physical…
We find that the cold gas can be magnetically launched from the disc surface with the help of the radiation pressure if the angular velocity of the radiation pressure dominated accretion disc is greater than a critical value, which…
Non-relativistic, magnetically-driven jets are constructed by taking self-consistently into account the feedback on the underlying accretion disc. It is shown that such jets are mostly described by the ejection index $\xi= \mbox{d} \ln \dot…
There are strong evidence for powerful jets in the low/hard state of black-hole X-ray binaries (BHXRBs). Here, we present a model in which electrons are accelerated once at the base of the jet, and are cooled by synchrotron emission and…
We investigate the generation of magnetic fields above black hole accretion discs due to the non-zero curl of the disc radiation field. By self consistently computing the components of the radiation flux and their curl, we show that the…
Three energy mechanisms invoking large-scale magnetic fields are incorporated in a model to interpret jet production in black hole (BH) systems, i.e., the Blandford-Znajek (BZ), the magnetic coupling (MC) and Blandford-Payne (BP) processes.…
We investigate impacts of stellar rotation and magnetic fields on black hole (BH) formation and its subsequent explosive activities, by conducting axisymmetric radiation-magnetohydrodynamics simulations of gravitational collapse of a 70…
Accreting black holes (BHs) launch relativistic collimated jets, across many decades in luminosity and mass, suggesting the jet launching mechanism is universal, robust and scale-free. Theoretical models and general relativistic…
Disc accretion on to a black hole is often misaligned from its spin axis. If the disc maintains a significant magnetic field normal to its local plane, we show that dipole radiation from Lense-Thirring precessing disc annuli can extract a…
The protostellar jets driven by the formation of the first stars are studied by using MHD nested grid simulations. Starting from a slowly rotating spherical cloud of 5.1 times 10^4 Msun permeated by a uniform magnetic field, we follow the…
Matter falling onto black holes, {also called} accretion discs, emit intense high-energy radiation. Accretion discs during {hard to hard intermediate} spectral states also emit bipolar outflows. Radiation drag was supposed to impose the…
Super-Eddington accretion discs with 3 and 15 dot M_E around black holes with mass 10 M_sun are examined by two-dimensional radiation hydrodynamical calculations extending from the inner disc edge to 5*10^4 r_g and lasting up to \sim 10^6…