Related papers: Two-dimensional Radiation-hydrodynamic Model for S…
Hypercritical accretion flows onto stellar mass black holes (BHs) are commonly considered as a promising model of central engines of gamma-ray bursts (GRBs). In this model a certain fraction of gravitational binding energy of accreting…
We use high-resolution zoom-in cosmological simulations to model outflow triggered by radiation and thermal drivers around the central mass accumulation during direct collapse within the dark matter (DM) halo. The maximal resolution is…
One possible scenario for the formation of massive black holes (BHs) in the early Universe is from the direct collapse of primordial gas in atomic-cooling dark matter haloes in which the gas is unable to cool efficiently via molecular…
We consider $r$-process nucleosynthesis in outflows from black hole accretion discs formed in double neutron star and neutron star -- black hole mergers. These outflows, powered by angular momentum transport processes and nuclear…
Tidal disruption events (TDEs) are luminous black hole (BH) transient sources, which are detected mainly in X-ray and optical bands. It is generally believed that the X-ray emission in TDEs is produced by an accretion disc formed as the…
We present three-dimensional MHD simulations of rotating radiatively inefficient accretion flows onto black holes. In the simulations, we continuously inject magnetized matter into the computational domain near the outer boundary, and we…
We calculate the structure of accretion disk around a spinning black hole for accretion rates 0.01 - 10 M_sun/s. The model is fully relativistic and treats accurately the disk microphysics including neutrino emissivity, opacity, electron…
Super-Eddington accretion onto black holes (BHs) may occur at ultraluminous compact X-ray sources in nearby galaxies, Galactic microquasars and narrow-line Seyfert 1 galaxies (NLS1s). Effects of electron scattering (opacity and…
Accretion onto supermassive black holes powers the most luminous persistent sources in the Universe, the so-called active galactic nuclei, whose emission is characterized by two distinct spectral components: thermal optical/ultraviolet…
An ejection mechanism of relativistic jets from slim disks is studied. Since the radiation pressure is dominant in the slim disk, radiative energy flow arises along the pressure gradient in the vertical direction. The divergence of the…
Hot, tenuous advection-dominated accretion flows around black holes are ideal sites for the Fermi acceleration of relativistic particles at standing shock waves in the accretion disc. Previous work has demonstrated that the…
Two related topics are discussed. 1. Accretion onto black holes at low and high (though not very high) rates is believed to proceed adiabatically ({\em ie} non-radiatively). It is argued that the liberated energy is carried off by an…
The periodic precession (162--day) and nodding (6.3--day) motions of the jets in SS433 are driven in the outer regions of the disc, whereas the jets themselves, being relativistic, are launched near the black hole at the disc centre. Given…
We show that black holes supplied with mass at hyper--Eddington rates drive outflows with mildly sub--relativistic velocities. These are $\sim 0.1 - 0.2c$ for Eddington accretion factors $\dot m_{\rm acc} \sim 10 - 100$, and $\sim…
Black-hole accretion systems are known to possess several distinct modes (or spectral states), such as low/hard state, high/soft state, and so on. Since the dynamics of the corresponding flows is distinct, theoretical models were separately…
Using the BH masses deduced from the empirical relation of Kaspi et al. (2000) and assuming that the optical luminosity is provided by the accretion disc, we show that Narrow Line Seyfert Galaxies 1 (NLS1s) accrete at super-Eddington rates,…
Massive stars may form in or be captured into AGN disks. Recent 1D studies employing stellar-evolution codes have demonstrated the potential for rapid growth of such stars through accretion up to a few hundred $M_\odot$. We perform 3D…
Three-dimensional simulations for the merger of binary neutron stars (BNSs) are performed in the framework of full general relativity. We pay particular attention to the black hole (BH) formation case and to the resulting mass of the…
Relativistic jets are launched from black hole (BH) X-ray binaries and active galactic nuclei when the disk accretion rate is below a certain limit (i.e., when the ratio of the accretion rate to the Eddingtion accretion rate, $\dot{m}$, is…
Context. The circumnuclear disk (CND) is presently the main supply of mass for the accretion onto the supermassive black hole (SMBH) in the Galactic Center (GC). While the accretion is relatively slow, it has been suspected that local…