相关论文: Efficiency of Thin Magnetically-Arrested Disks Aro…
The classical, relativistic thin-disk theory of Novikov and Thorne (NT) predicts a maximum accretion efficiency of 40% for an optically thick, radiatively efficient accretion disk around a maximally spinning black hole (BH). However, when a…
The radiative efficiency of super-Eddington accreting black holes (BHs) is explored for magnetically-arrested disks (MADs), where magnetic flux builds-up to saturation near the BH. Our three-dimensional general relativistic radiation…
Accreting black holes (BHs) produce intense radiation and powerful relativistic jets, which are affected by the BH's spin magnitude and direction. While thin disks might align with the BH spin axis via the Bardeen-Petterson effect, this…
Black hole (BH) spin can play an important role in galaxy evolution by controlling the amount of energy and momentum ejected from near the BH into the surroundings. We focus on radiatively-inefficient and geometrically-thick…
Prevalent around luminous accreting black holes, thin discs are challenging to resolve in numerical simulations. When the disc and black hole angular momentum vectors are misaligned, the challenge becomes extreme, requiring adaptive meshes…
We present two general relativistic radiation magnetohydrodynamics (GRRMHD) simulations of magnetically arrested disks (MADs) around non-spinning ($a_*=0$) and spinning ($a_*=0.9$) supermassive black holes (BHs). In each simulation, the…
Relativistic collimated outflows, or jets, provide a crucial mode of active galactic nucleus feedback. Although jets extract their energy from the black hole (BH) rotation, their effect on the BH spin is poorly understood. Because the spin…
Gas falling into a black hole (BH) from large distances is unaware of BH spin direction, and misalignment between the accretion disc and BH spin is expected to be common. However, the physics of tilted discs (e.g., angular momentum…
We explore the presence of torques at the inner edges of geometrically-thin black hole accretion disks using 3-dimensional magnetohydrodynamic (MHD) simulations in a pseudo-Newtonian potential. By varying the saturation level of the…
Numerical simulation of magnetohydrodynamic (MHD) turbulence makes it possible to study accretion dynamics in detail. However, special effort is required to connect inflow dynamics (dependent largely on angular momentum transport) to…
We describe global, 3D, time-dependent, non-radiative, general-relativistic, magnetohydrodynamic simulations of accreting black holes (BHs). The simulations are designed to transport a large amount of magnetic flux to the center, more than…
Luminous active galactic nuclei (AGN) and X-Ray binaries (XRBs) often contain geometrically thin, radiatively cooled accretion discs. According to theory, these are -- in many cases -- initially highly misaligned with the black hole…
By studying three-dimensional, radiative, global simulations of sub-Eddington, geometrically thin black hole accretion flows we show that thin disks which are dominated by magnetic pressure are stable against thermal instability. Such disks…
Spinning supermassive black holes (BHs) in active galactic nuclei (AGN) magnetically launch relativistic collimated outflows, or jets. Without angular momentum supply, such jets are thought to perish within $3$ orders of magnitude in…
Recent general relativistic magneto-hydrodynamic (MHD) simulations of accretion onto black holes have shown that, contrary to the basic assumptions of the Novikov-Thorne model, there can be substantial magnetic stress throughout the…
Motivated by the fact that the universe is dominated by dark matter and dark energy, we consider rotating black holes surrounded by perfect fluid dark matter and study the accretion process in thin disk around such black holes. Here, we are…
The exact time-dependent solution is obtained for a magnetic field growth during a spherically symmetric accretion into a black hole (BH) with a Schwarzschild metric. Magnetic field is increasing with time, changing from the initially…
We perform general relativistic simulations of magnetized, accreting disks onto spinning binary black holes (BHBHs) with different mass ratios (MRs). The magnitude of the individual BH spins are all $\chi= 0.26$ and lie either along the…
We present a set of six general relativistic, multi-frequency, radiation magnetohydrodynamic simulations of thin accretion disks with different target mass accretion rates around black holes with spins ranging from non-rotating to rapidly…
We perform three general-relativistic magnetohydrodynamic simulations of black hole accretion designed to test how sensitive results are to grid resolution in the jet region. The cases differ only in numerics, modelling the same physical…