Because of the contamination of jets, using the size – continuum luminosity relation can overestimate the broad line region (BLR) size and black hole mass for radio-loud AGNs. We propose a new relation between the BLR size and Hβ emission line luminosity and present evidences for using it to get more accurate black hole masses of radio-loud AGNs. For extreme radio-loud AGNs such as blazars with...

We explore the relation between the linear length of radio core and the central black hole mass for a sample of radio-loud active galactic nuclei (AGNs). An empirical relation between the size of the broad line region (BLR) and optical luminosity is used to estimate the size of the BLR. The black hole mass is derived from Hβ line width and the radius of the BLR on the assumption that the clouds...

We demonstrate that the luminosity function of the recently detected population of actively star-forming galaxies at redshift three and the B-band QSO luminosity function at the same redshift can both be matched with the mass function of dark matter haloes predicted by standard variants of hierarchical cosmogonies for lifetimes of optically bright QSOs anywhere in the range 10 to 10 yr. There i...

We investigate the relationship between soft X-ray luminosity and mass for low redshift clusters of galaxies by comparing observed number counts and scaling laws to expectations of ΛCDM cosmologies. We use a three-parameter model for the conditional probability of luminosity given mass and epoch, described as a log-normal distribution of fixed width centered on a power-law scaling relation, L ∝...

Massive black holes detected in the centers of many nearby galaxies are linearly correlated with the luminosity of the host bulge, the black hole mass being about 0.1% of the bulge mass. An even stronger relation exists between the BH mass (Mbh) and the stellar velocity dispersion in the host bulge. We show that massive BHs of AGNs (measured by reverberation mapping) and their bulge luminosity ...

We use the RASS-SDSS galaxy cluster sample to compare the quality of optical and X-ray luminosities as predictors of other cluster properties such as their masses, temperatures, and velocity dispersions. We use the SDSS spectroscopic data to estimate the velocity dispersions and the virial masses of a subsample of 69 clusters within r500 and r200. The ASCA temperature of the intracluster medium...

Based on recent X-ray observations of the Milky Way, Magellanic Clouds and nearby starburst galaxies we study population of high mass X-ray binaries, their connection with ultra-luminous X-ray sources and relation to the star formation. Although more subtle SFR dependent effects are likely to exist, the data in the lg(LX) ∼ 36 − 40.5 luminosity range are broadly consistent with existence of a "...

We postulate that supermassive black-holes grow in the centers of galaxies until they unbind the galactic gas that feeds them. We show that the corresponding self-regulation condition yields a correlation between black-hole mass (Mbh) and galaxy velocity dispersion (σ) as inferred in the local universe, and recovers the observed optical and X-ray luminosity functions of quasars at redshifts up ...

We report 4.5 μm luminosities for 27 nearby (D . 5 Mpc) dwarf irregular galaxies measured with the Spitzer Infrared Array Camera. We have constructed the 4.5 μm luminosity-metallicity (L–Z) relation for 25 dwarf galaxies with secure distance and interstellar medium oxygen abundance measurements. The 4.5 μm L–Z relation is 12+log(O/H) = (5.78 ± 0.21) + (−0.122 ± 0.012) M[4.5], where M[4.5] is th...