Related papers: Analytic study of mass segregation around a massiv…
A variety of host galaxy (bulge) parameters are examined in order to determine their predictive power in ascertaining the masses of the supermassive black holes (SMBH) at the centers of the galaxies. Based on a sample of 23 nearby galaxies,…
We consider collisions occurring between stars moving near the speed of light around supermassive black holes (SMBHs) with mass $M_{\bullet}\gtrsim10^8\,M_\odot$, without being tidally disrupted. In this SMBH range, for sun-like stars, the…
We constrain the ratio of black hole (BH) mass to total stellar mass of type-1 AGN in the COSMOS survey at 1<z<2. For 10 AGN at mean redshift z~1.4 with both HST/ACS and HST/NICMOS imaging data we are able to compute total stellar mass…
We use a large sample of upper limits and accurate estimates of supermassive black holes masses coupled with libraries of host galaxy velocity dispersions, rotational velocities and photometric parameters extracted from Sloan Digital Sky…
This article summarizes recent work on the luminosity and mass distribution of the Galactic bulge and disk, and on the mass of the Milky Way's dark halo. A new luminosity model consistent with the COBE NIR data and the apparent magnitude…
Recent measurements, of the velocities of stars near the center of the Milky Way have provided the strongest evidence for the presence of a supermassive black hole in a galaxy, but the observational uncertainties poorly constrain many of…
New kinematic data and modeling efforts in the past few years have substantially expanded and revised dynamical measurements of black hole masses (Mbh) at the centers of nearby galaxies. Here we compile an updated sample of 72 black holes…
We present results from infrared spectroscopic projects that aim to test the relation between the mass of a black hole, M_BH, and the velocity dispersion of the stars in its host-galaxy bulge. We demonstrate that near-infrared,…
We simulate mergers between galaxies containing collisionally-relaxed nuclei around massive black holes (MBHs). Our galaxies contain four mass groups, representative of old stellar populations; a primary goal is to understand the…
We study the distribution of accretion rates onto supermassive black holes (SMBH) in AGNs of the local Universe ($z<0.15$) based on near-infrared and hard X-ray surveys (2MASS and Swift/BAT). Using sufficiently accurate black hole mass…
The selective light absorption in space has been raised in astronomical literature. The substance producing the absorption must have some mass; thus the question is how large it is. We develop a dynamical model of the Milky Way system,…
The formation and evolution of binary black holes (BH) is studied using the modern evolutionary scenario for very massive stars with high mass loss (Vanbeveren et al. 1998). Main sequence stars with masses $M>35 M_\odot$ are assumed to form…
We have embarked in an HST program to determine the masses of black holes in spiral galaxies directly by measuring the line emission arising from an extended accretion disk. For each of the galaxies in our sample we have measured the…
Coevolution between supermassive black holes (BHs) and their host galaxies is universally adopted in models for galaxy formation. In the absence of feedback from active galactic nuclei, simulated massive galaxies keep forming stars in the…
We follow the collapse in axisymmetry of a uniformly rotating, supermassive star (SMS) to a supermassive black hole (SMBH) in full general relativity. The initial SMS of arbitrary mass $M$ is marginally unstable to radial collapse and…
The mass function of super-massive black holes in our cosmic neighborhood is required to understand the statistics of their activity and consequently the origin of the ultra high energy particles. We determine a mass function of black hole…
Super-Massive Black Holes reside in galactic nuclei, where they exhibit episodic bright flares due to accretion events. Taking into account relativistic effects, namely, the boosting and lensing of X-ray flares, we further examine the…
We study the dynamical evolution of eccentric massive black hole binaries (MBHBs) interacting with unbound stars by means of an extensive set of three body scattering experiments. Compared to previous studies, we extend the investigation…
The first stars forming in minihaloes at redshifts greater than 20 may have been very massive and could have left behind massive black hole (MBH) remnants. In a previous paper we investigated the hierarchical merging of these MBHs and their…
We estimate the rate at which stars are captured by supermassive black holes (BHs) in the centres of bulges and elliptical galaxies assuming that these initially had an isothermal cusp (rho ~ r^{-2} with velocity dispersion sigma_*). If…