Related papers: Systematic Errors in the Estimation of Black Hole …
Using long-duration general relativistic magnetohydrodynamic simulations of radiatively inefficient accretion discs, the energy, momentum and mass outflow rates from such systems are estimated. Outflows occur via two fairly distinct modes:…
A mass correlation of central black holes and their spheroids ~0.002(within a factor of three) is suggested by Hubble Space Telescope (HST) and various ground-based CCD photometries of early type galaxies. The near-IR images of quasar hosts…
We investigate the global properties of the radiation emitted by the accretion disk around Kerr black holes. Using the Kerr blackbody (KERRBB) numerical model, we build an analytic approximation of the disk emission features focusing on the…
The detailed feeding and feedback mechanisms of Active Galactic Nuclei (AGN) are not yet well known. For low-luminosity and obscured AGN, as well as late-type galaxies, determining the central black hole (BH) masses is challenging. Our goal…
The mass of massive black holes in quasar cores can be deduced using the typical velocities of Hb-emitting clouds in the Broad Line Region (BLR) and the size of this region. However, this estimate depends on various assumptions and is…
We calibrate reverberation-based black hole masses in active galactic nuclei (AGNs) by using the correlation between black hole mass, M, and bulge/spheroid stellar velocity dispersion, sigma. We use new measurements of sigma for 6 AGNs and…
We present new observations leading to an improved black hole mass estimate for the Seyfert 1 galaxy NGC 4593 as part of a reverberation-mapping campaign conducted at the MDM Observatory. Cross-correlation analysis of the H_beta…
We measure the correlation between black-hole mass $M_{\rm BH}$ and host stellar mass $M_*$ for a sample of 38 broad-line quasars at $0.2\lesssim z\lesssim 0.8$ (median redshift $z_{\rm med}=0.5$). The black-hole masses are derived from a…
Binary black hole (BBH) mergers detected via gravitational waves are addressing key open questions in astrophysics, cosmology, and fundamental physics. Our scientific conclusions rely on extracting accurate source parameters, for which we…
A new approach to constraining or determining the spin of a massive black hole is proposed. A key parameter in the analysis is the dimensionless ratio, r, of the energy released to the mass of the hole. It is shown that the black hole spin,…
We evaluate the Brownian motion of a massive particle ("black hole") at the center of a galaxy using N-body simulations. Our galaxy models have power-law central density cusps like those observed at the centers of elliptical galaxies. The…
A typical galaxy is thought to contain tens of millions of stellar-mass black holes, the collapsed remnants of once massive stars, and a single nuclear supermassive black hole. Both classes of black holes accrete gas from their…
We give an approach to studying the critical behaviour that has been observed in numerical studies of gravitational collapse. These studies suggest, among other things, that black holes initially form with infinitesimal mass. We show…
The innermost regions in active galactic nuclei (AGNs) were not being spatially resolved so far but spectropolarimetry can provide us insight about their hidden physics and the geometry. From spectropolarimetric observations in broad…
We describe a method for the determination of black-hole masses based on information inferred from high-energy spectra. It is required that the spectral energy distribution consist of thermal and Comptonized components. One can then, in…
We prescribe a method to study the effects of self-gravity of accretion disk around a black hole associated with long Gamma Ray Bursts (GRBs) in an evolving background Kerr metric. This is an extension to our previous work where we…
The mass of a black hole is the sum of the irreducible mass and the mass associated with the rotational or spin energy of the black hole. The contribution of spin energy (divided by $c^2$) to the total black hole mass is studied here for…
We introduce a novel black hole mass function which realistically models the physics of star formation and pair instability supernova with a minimal number of parameters. Applying this to all events in the LIGO-Virgo GWTC-2 catalog, we…
Based on the measured sizes of broad line region of the reverberation-mapping AGN sample, two new empirical relations are introduced to estimate the central black hole masses of radio-loud high-redshift ($z > 0.5$) AGNs. First, using the…
We present the results of a recent reverberation-mapping campaign undertaken to improve measurements of the radius of the broad line region and the central black hole mass of the quasar PG 2130+099. Cross correlation of the 5100 angstrom…