Related papers: The Radio-Optical Correlation in Steep-Spectrum Qu…
We compiled a sample of 24 flat-spectrum radio quasars (FSRQs), 21 BL Lacs, 13 FRI and 12 FRII radio galaxies to study the jet power and broad-line luminosity relation, and the jet power and black hole mass relation. Furthermore, we obtain…
To some extent, all Galactic binary systems hosting a compact object are potential `microquasars', so much as all galactic nuclei may have been quasars, once upon a time. The necessary ingredients for a compact object of stellar mass to…
The radio/X-ray correlation is one of the most important pieces of observational evidence of the disk-jet connection in accreting compact objects. However, a growing number of X-ray binaries seem to present deviations from the universal…
We investigate the optical variability of 7658 quasars from SDSS Stripe 82. Taking advantage of a larger sample and relatively more data points for each quasar, we estimate variability amplitudes and divide the sample into small bins of…
Combined investigations of the clustering properties of galaxies of different spectral type and high-redshift quasars strongly suggest local ellipticals to be the parent population of optically bright Active Galactic Nuclei (AGN). However,…
Results from a few decades of reverberation mapping (RM) studies have revealed a correlation between the radius of the broad-line emitting region (BLR) and the continuum luminosity of active galactic nuclei. This "radius-luminosity"…
We explore the evolution of the X-ray luminosity function of quasars and the intrinsic correlation between the X-ray and 2500\AA $\,$ ultraviolet luminosities, utilizing techniques verified in previous works and a sample of over 4000…
We find angular correlations between high redshift radio selected QSOs from the 1 Jy Catalog and APM galaxies on ~1 degree scales. We demonstrate that observed correlations are qualitatively consistant with a gravitational lensing…
We present our latest results on the connection between accretion rate and relativistic jet power in AGN, by using a large sample which includes mostly blazars, but contains also some radio--galaxies. The jet power can be traced by…
We investigate the populations and evolution of normal and active galaxies by extending the infrared source count model of Rowan-Robinson (2001) into the radio. The FIR-radio correlation is used to extend the SEDs to the radio region and it…
Compact radio cores associated with relativistic jets are often observed in both active galactic nuclei and X-ray binaries. Their radiative properties follow some general scaling laws which primarily depend on their masses and accretion…
Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies…
Some different correlations between optical-UV variability and other quasar properties, such as luminosity, black hole mass and rest-frame wavelength, were discovered. The positive correlation between optical-UV variability amplitude and…
The properties of high redshift quasar host galaxies are studied, in order to investigate the connection between galaxy evolution, nuclear activity, and the formation of supermassive black holes. We combine new near-infrared observations of…
We report initial results from the detection of optical emission in the arcsecond-scale radio jets of two quasars utilizing images from the {\it Hubble Space Telescope} archive. The optical emission has a very knotty appearance and is…
We consider implications of our new model of quasar lifetimes and light curves for the quasar luminosity function (LF) at different frequencies and redshifts. In our picture, quasars evolve rapidly and the lifetime depends on both their…
In this paper, we explore the physics of the accretion and jet in narrow-line Seyfert 1 galaxies (NLS1). Specifically, we compile a sample composed of 16 nearby NLS1 with $L_{\rm bol}/L_{\rm Edd} \gtrsim 0.1$. We investigate the mutual…
Black holes of stellar mass and neutron stars in binary systems are first detected as hard X-ray sources using high-energy space telescopes. Relativistic jets in some of these compact sources are found by means of multiwavelength…
[Context] The broadband spectral energy distribution of microquasars has proven to be a valuable tool for assessing the roles of jets and accretion flows in microquasars, as well as the coupling between the two. The coupling might manifest…
The tight relationship between the masses of black holes and galaxy spheroids in nearby galaxies implies a causal connection between the growth of these two components. Optically luminous quasars host the most prodigious accreting black…