相关论文: Plasma injection and outflow formation in Kerr bla…
The effect of mass and energy loading on the efficiency at which energy can be extracted magnetically from a Kerr black hole is explored, using a semi-analytic, ideal MHD model that incorporates plasma injection on magnetic field lines. We…
We construct a semi-analytic model for MHD flows in Kerr geometry, that incorporates energy loading via neutrino annihilation on magnetic field lines threading the horizon. We compute the double-flow structure for a wide range of energy…
Accreting black hole sources show variable outflows at different mass scales. For instance, in the case of galactic nuclei, our own galactic center Sgr A* exhibits flares and outbursts in the X-ray and infrared bands. Recent studies suggest…
We examine Poynting flux generation due to pair plasma accreting onto a slowly rotating black hole. In particular, we consider the possibility of an outgoing flux at the horizon. Our approach is based on a two-fluid model representing a…
Most models for blazars and gamma-ray bursts involve relativistic plasma outflows powered by accretion processes onto black holes. The blast wave physics developed for cosmological models of GRBs is reviewed. Two points relevant for blazar…
The hot inner flow in black-hole X-ray binaries is not just a static corona rotating around the black hole, but it must be partially outflowing. We have developed a model, in which Comptonization takes place in this outflowing corona. We…
We present our recent results from numerical simulations of a magnetized flow in the vicinity of a black hole in the context of the collapsar model for GRBs. The simulations show that after an initial transient, the flow settles into a…
Recent observations of supermassive black holes have brought us new information on their magnetospheres. In this study we attempt a theoretical modelling of the coupling of black holes with their jets and discs, via three innovations.…
Introducing a spherical, steady, self-supported pair-plasma pressure mediated shock surface around a Schwarzschild black hole as the effective physical atmosphere which may be responsible for the generation of astrophysical mass outflows…
Combined influence of rotation of a black hole and ambient magnetic fields creates conditions for powerful astrophysical processes of accretion and outflow of matter which are observed in many systems across the range of masses; from…
Black holes attract gaseous material from the surrounding environment. Cosmic plasma is largely ionized and magnetized because of electric currents flowing in the highly conductive environment near black holes; the process of accretion then…
Gas flows in the presence of two independently-rotating nested bars remain not fully understood, which is likely to play an important role in fueling the central black hole. We use high-resolution hydrodynamical simulations with detailed…
Hinode observations have provided a new view of outflows from the Sun. These have been focussed in particular on flows emanating from the edges of active regions. These flows are long lasting and seem to exist to some extent in every active…
We examine energy conversion from accreting pair plasma to outgoing Poynting flux by black hole rotation. Our approach is based on a two-fluid model consisting of collisionless pair plasma. The electric potential is not constant along…
Recent observations suggest that in black hole X-ray binaries jet/outflow formation is related to the hot plasma in the vicinity of the black hole, either in the form of an advection-dominated accretion flow at low accretion rates or in a…
Accreting black holes are responsible for producing the fastest, most powerful outflows of matter in the Universe. The formation process of powerful jets close to black holes is poorly understood, and the conditions leading to jet formation…
We present results of a study of non-thermal, time-dependent particle injection in a corona around an accreting black hole. We model the spectral energy distribution of high-energy flares in this scenario. We consider particle interactions…
(Abridged) An issue of considerable interest in the theory of jet formation by the Blandford-Znajek mechanism, is how plasma is being continuously supplied to the magnetosphere to maintain it in a force-free state. Injection of…
There are now several types of relativistic flows in astrophysical settings. The foremost examples are jets and disks orbiting spinning black holes, pulsar winds and gamma ray bursts. As discussed at this meeting, these flows exhibit…
Cosmological gamma-ray bursts are probably powered by systems harboring a rotating black hole. We show that frame-dragging creates baryon-poor outflows in a differentially rotating gap along an open magnetic flux-tube with dissipation…