Related papers: Magnetic Fields of Black Holes and the Variability…
We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting…
We test a novel method for estimating black hole masses ($M_{\rm BH}$) in obscured active galactic nuclei (AGN) that uses proxies to measure the full-width half maximum of broad H$\alpha$ (FWHM$_{\rm bH\alpha}$) and the accretion disk…
We examine the thin accretion disk behaviors surrounding black holes embedded in cold dark matter halos and scalar field dark matter halos. We first calculate the event horizons and derive the equations of motion and effective potential in…
Studying a sample of both strongly and weakly active galactic nuclei with measured masses and 5 GHz and 2-10 keV core luminosities, together with a few galactic black holes simultaneously observed in the radio and X-ray bands, Merloni,…
Here we discuss the effects of strong gravity that can be observed in electromagnetic spectra of active galactic nuclei (AGN). According to the unification model of an AGN, there is a supermassive black hole ($10^7 - 10^9 M_\odot$) in its…
We analyze a sample of 32 galaxies for which a dynamical estimate of the mass of the hot stellar component, M_bulge, is available. For each of these galaxies, we calculate the mass of the central black hole, M_BH, using the tight empirical…
Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and…
We present a novel approach to study the global structure of steady, axisymmetric, advective, geometrically thin, magnetohydrodynamic (MHD) accretion flow around black holes in full general relativity (GR). Considering ideal MHD conditions…
Although disk accretion onto compact objects - white dwarfs, neutron stars, and black holes - is central to much of high energy astrophysics, the mechanisms which enable this process have remained observationally elusive. Accretion disks…
The astrophysical consequences of the presence of a quintessence scalar field on the evolution of the horizon and on the accretion disk surrounding a static black hole, in the Scalar-Vector-Tensor version of Modified Gravity (MOG), are…
An analytical expression for the disc power is derived based on an equivalent circuit in black hole (BH) magnetosphere with a mapping relation between the radial coordinate of the disc and that of unknown astrophysical load. It turns out…
Large scale magnetic fields pervade the cosmic environment where the astrophysical black holes are often embedded and influenced by the mutual interaction. In this contribution we outline the appropriate mathematical framework to describe…
We consider the bound states of the massive scalar field around a rotating black hole immersed in the asymptotically uniform magnetic field. In the regime of slow black hole rotation, the Klein-Gordon equation allows separation of…
Recent studies of active galactic nuclei (AGN) found a statistical inverse linear scaling between the X-ray normalized excess variance $\sigma_{\rm rms}^2$ (variability amplitude) and the black hole mass spanning over $M_{\rm BH}=10^6-…
General Relativistic (GR) Magnetohydrodynamic (MHD) simulations of black hole accretion find significant magnetic stresses near and inside the innermost stable circular orbit (ISCO), suggesting that such flows could radiate in a manner…
In a recent work we demonstrated that a novel X-ray scaling method, originally introduced for Galactic black holes (GBHs), can be reliably extended to estimate the mass of supermassive black holes accreting at a moderate to high level. Here…
Diskoseismology, the theoretical study of normal mode oscillations in geometrically thin, optically thick accretion disks, is a strong candidate to explain some QPOs in the power spectra of many black hole X-ray binary systems. The…
In this proceeding, we provide a novel approach to study the General Relativistic Magnetohydrodynamic (GRMHD) accretion flows around rotating black holes (BHs). In doing so, we choose a sub-Keplerian distribution of angular momentum of the…
We report the discovery of the ``mm fundamental plane of black-hole accretion'', which is a tight correlation between the nuclear 1 mm luminosity ($L_{\rm \nu, mm}$), the intrinsic $2$ -- $10$~keV X-ray luminosity ($L_{\rm X,2-10}$) and the…
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…