Related papers: Jet formation in BL Lacertae objects with differen…
Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is…
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…
We present various instability mechanisms in the accreting black hole systems which might indicate at the connection between the accretion disk and jet. The jets observed in microquasars can have a persistent or blobby morphology.…
Models of jet production in black hole systems suggest that the properties of the accretion disk - such as its mass accretion rate, inner radius, and emergent magnetic field - should drive and modulate the production of relativistic jets.…
The current popular model for launching, accelerating and collimating astrophysical jets is based on magnetohydrodynamics (MHD). AGN jets are most probably powered by energy extracted from either an accretion disk or a rapidly rotating…
Context: Accretion onto galactic and supermassive black holes occurs in different modes, which are documented in hard and soft spectral states, commonly attributed to an advection-dominated flow (ADAF) inside a truncated disk and standard…
When the matter from a companion star is accreted towards the central compact accretor, i.e. a black hole (BH) or a neutron star (NS), an accretion disc and a jet outflow will form, providing bight X-ray and radio emission, which is known…
In this Letter, we suggest that the relativistic protons powering the outflows emanating from radio-loud systems containing black holes are accelerated at standing, centrifugally-supported shocks in hot, advection-dominated accretion disks.…
Accreting black holes produce collimated outflows, or jets, that traverse many orders of magnitude in distance, accelerate to relativistic velocities, and collimate into tight opening angles. Of these, perhaps the least understood is jet…
Astrophysical objects possessing a material surface (white dwarfs, young stars, etc.) may accrete gas from the disc through the so-called surface boundary layer (BL), in which the angular velocity of the accreting gas experiences a sharp…
We consider the power of a relativistic jet accelerated by the magnetic field of an accretion disc. It is found that the power extracted from the disc is mainly determined by the field strength and configuration of the field far from the…
The current paradigm foresees that relativistic jets are launched as magnetically dominated flows, whose magnetic power is progressively converted to kinetic power of of the matter of the jet, until equipartition is reached. Therefore, at…
Low mass X-ray transients (LMXRTs) hosting black hole candidates (BHCs) display on average a factor of ~100 larger swing in the minimum (quiescent) to maximum (outburst) X-ray luminosity than neutron stars (NSs), despite the fact that the…
We have analyzed the optical and radio properties of a sample of 3CR FR I radio galaxies which have Hubble Space Telescope imaging capable of detecting optical cores. The jet powers of the FR I radio galaxies are estimated from their…
We examine production of Li on the surface of a low-mass secondary in a black hole soft X-ray transient (BHSXT) through the spallation of CNO nuclei by neutrons which are ejected from a hot (> 10 MeV) advection-dominated accretion flow…
The growing evidence for supermassive black holes in the centres of nearby galaxies has brought into sharper focus the question of why elliptical galaxies, rich in hot gas, do not possess quasar-like luminosities. Recent studies suggest…
The inward flow of matter through accretion disks is driven by MHD turbulence. Global general relativistic MHD simulations shed quantitative light on this process, revealing a number of aspects of accretion previously unrecognized. Among…
The optical-UV continuum of quasars is broadly consistent with the emission from a geometrically thin optically thick accretion disk (AD). The AD produces the ionizing continuum which powers the broad and narrow emission lines. The maximum…
First evidences of IR excess and disk mass accretion (strong H$\alpha$ emission) around brown dwarfs seem to indicate the existence of circumstellar disks around these sub-stellar objects. Nothing is known at the present time about outflows…
In this Letter we investigate the properties of advection-dominated accretion flows (ADAFs) fed by the evaporation of a Shakura-Sunyaev accretion disk (SSD). In our picture the ADAF fills the central cavity evacuated by the SSD and extends…