Related papers: Black hole mass and variability in quasars
We investigate how accretion episodes onto massive black holes power quasars and AGN while they accumulate mass into the holes. We compute both the trend and the stochastic component to the trigger of the accretion events, as provided by…
Broad absorption line (BAL) quasars probe the high velocity gas ejected by luminous accreting black holes. BAL variability timescales place constraints on the size, location, and dynamics of the emitting and absorbing gas near the…
We present the results of our recent Hubble Space Telescope imaging study, in which we have successfully deconvolved host and nuclear flux for the some of the most luminous quasars in the Universe. Host morphologies have been recovered for…
We compare the evolution with cosmic time of the star-formation rate per comoving volume in galaxies and of the volume emissivity by Active Galactic Nuclei, as a clue to understand the relationship between black hole accretion and the…
Black hole spins affect the efficiency of the "classical" accretion processes, hence the radiative output from quasars. Spins also determine how much energy is extractable from the hole itself. Recently it became clear that massive black…
The `fundamental plane of black hole accretion' (FP), a relation between the radio luminosities ($L_R$), X-ray luminosities ($L_X$), and masses ($M_{BH}$) of hard/quiescent state black hole binaries and low-luminosity active galactic…
Obscured or narrow-line active galaxies offer an unobstructed view of the quasar environment in the presence of a luminous and vigorously accreting black hole. We exploit the large new sample of optically selected luminous narrow-line…
We compile black hole (BH) masses for $\sim 60,000$ quasars in the redshift range $0.1 \lesssim z \lesssim 4.5$ included in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS), using virial BH mass estimators based on the \hbeta,…
We address the correlations of black hole (BH) mass with four different host-galaxy properties from eleven existing data sets. To guide theoretical understanding, we first try to quantify the tightness of the intrinsic correlations. Given…
We have analyzed the evolution of mass of a stationary black hole in the standard FRW cosmological model. The evolution is determined specifically about the time of transition from the earlier matter to the later exotic dark energy…
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…
Local and distant measurements of the Hubble constant are in significant tension: local measurements of the Hubble constant appear to show a Universe that is significantly contracted when compared to distant measurements. From the point of…
We investigate the variation of black hole masses (Mbh) as a function of their host galaxy stellar mass (Mstar) and half-light radius (Re). We confirm that the scatter in Mbh within this plane is essentially the same as that in the Mbh -…
The gravitational wave signature of a binary black hole (BBH) merger is dependent on its component mass and spin. If such black holes originate from rapidly rotating progenitors, the large angular momentum reserve in the star could drive a…
We investigate the relationship between disc winds, radio jets, accretion rates and black hole masses of a sample of $\sim$100k quasars at z $\approx$ 2. Combining spectra from the 17th data release of the Sloan Digital Sky Survey (SDSS)…
Accretion disks around supermassive black holes in active galactic nuclei produce continuum radiation at ultraviolet and optical wavelengths. Physical processes in the accretion flow lead to stochastic variability of this emission on a wide…
We report here the first results from a 15-yr long variability monitoring of the z=2.0 quasar QSO B1312+7837. It shows luminosity changes with a period P~6.13 yr (P~2.04 yr at rest frame) and an amplitude of ~0.2mag, superimposed on a…
The variability of submillimeter emission provides a useful tool to probe the accretion physics in low-luminosity active galactic nuclei. We accumulate four years of observations using Submillimeter Array for Centaurus A, NGC 4374, NGC…
In the local universe, the masses of Super-Massive Black-Holes (SMBH) appear to correlate with physical properties of their hosts, including the mass of the dark-matter halos. At higher redshifts, we observe the growth of SMBHs indirectly…
We show that the luminosity function of the actively star-forming Lyman break galaxies and the B-band quasar luminosity function at $z = 3$ can be fit reasonably well with the mass function of collapsed galaxy scale dark matter haloes…