Related papers: Broad reprocessed Balmer emission from warped accr…
Here we investigate the connection of broad emission line shapes and continuum light curve variability time scales of type-1 Active Galactic Nuclei (AGN). We developed a new model to describe optical broad emission lines as an accretion…
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…
We measure the black hole mass and investigate the accretion flow around the local ($z=0.0502$) quasar PG 1119+120. Spectroscopic monitoring with Calar Alto provides H$\beta$ lags and linewidths from which we estimate a black hole mass of…
Radiation emitted from an accretion disk around a massive black hole is a widely discussed model for the UV/soft X-ray excess emission observed in the spectra of many AGN. A self-consistent calculation of the structure and the emerging…
The dynamics of two massive black holes in a rotationally supported nuclear disc of 10^8 solar masses is explored using N-Body/SPH simulations. Gas and star particles are co-present in the disc. Described by a Mestel profile, the disc has a…
The structure of the broad emission line region (BLR) in active galactic nuclei (AGN) remains unclear. We test in this paper a flattened configuration model for BLR. The virial theorem, by taking into account the disc shape of BLR, allows…
X-ray reverberation has proven to be a powerful tool capable of probing the innermost region of accretion disks around compact objects. Current theoretical effort generally assumes that the disk is geometrically thin, optically thick and…
In this work we show that Bardeen-Petterson accretion disks can exhibit unique, detectable features in relativistically broadened emission line profiles. Some of the unique characteristics include inverted line profiles with sharper red…
Recent X-ray observations of Galactic Black Hole Candidates and AGNs and Seyfert galaxies reveal the broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. Simulation indicates that at low…
It has been recently proposed that the broad line region in active galactic nuclei originates from dusty clouds driven from the accretion disk by radiation pressure, at a distance from the black hole where the disk is cooler than the dust…
We investigate the accretion disk for a sort of regular black holes which are characterized by sub-Planckian curvature and Minkowskian core. We derive null geodesics outside the horizon of such regular black holes and analyze the feature of…
We present disk wind model calculations for the broad emission lines seen in the ultraviolet spectra of the X-ray binary Hercules X-1. Recent HST/STIS observations of these lines suggest that they are kinematically linked to the orbital…
The spectra of active galactic nuclei exhibit broad-emission lines that presumably originate in the Broad-Line Region (BLR) with gaseous-dusty clouds in a predominantly Keplerian motion around the central black hole. Signatures of both…
The high-energy particle production in the accretion flow onto black holes can be a key physics to explain the high-energy neutrino background. While the single-zone approximation has been commonly adopted in studies of the high-energy…
Over the last few years X-ray observations of broad-line radio galaxies (BLRGs) by ASCA, RXTE and BeppoSAX have shown that these objects seem to exhibit weaker X-ray reflection features (such as the iron K\alpha line) than radio-quiet…
The X-ray emission from accreting black hole (BH) systems displays strong variability. Short reverberation lags are expected between the primary hard X-ray continuum and the reprocessed disc emission. These lags depend on light-travel…
Most massive galaxies contain a supermassive black hole (SMBH) at their center. When galaxies merge, their SMBHs sink to the center of the new galaxy where they are thought to eventually merge. During this process an SMBH binary is formed.…
Accretion disks around active galactic nuclei are potentially unstable to star formation at large radii. We note that when the compact objects formed from some of these stars spiral into the central supermassive black hole, there is no…
Radiation from a narrow circular ring shows a characteristic double-horn profile dominated by photons having energy around the maximum or minimum of the allowed range, i.e. near the extremal values of the energy shift. The energy span of a…
Observations of the fluorescent Fe K-alpha emission line from the inner accretion flows of stellar mass black holes in X-ray binaries and supermassive black holes in Active Galactic Nuclei have become an important tool to study the…