Recent VLBI observations have identified several compact radio sources which have symmetric structures on parsec scales, and exhibit H i absorption which appears to be associated with the active nucleus. These sources are uniquely well suited to investigations into the physics of the central engines, in particular to studies of the kinematics of the gas within 100 pc of the core. In these compa...

The recent discoveries of X-ray and optical counterparts for GRBs, and a possible discovery of a host galaxy, implies that a direct measurement of the red-shift of some GRBs host galaxies is eminent. We discuss the implications of such measurements. They could enable us to determine the GRBs luminosity distribution, the variation of the rate of GRBs with cosmic time, and even, under favorable c...

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...

Received ; accepted – 2 – ABSTRACT The recent discoveries of X-ray and optical counterparts for GRBs, and a possible discovery of a host galaxy, implies that a direct measurement of the red-shift of some GRBs host galaxies is eminent. We discuss the implications of such measurements. They could enable us to determine the GRBs luminosity distribution, the variation of the rate of GRBs with cosmi...

I discuss the advances in our understanding of the physics and morphology of the innermost regions of AGNs which will be possible thanks to the XMM unprecedented sensitivity and its moderate to high energy resolution.

The brightest quasars were born 10 billion years ago during the Quasar Epoch. These bigger and brighter than any of formed after, this paper seeks to find out why. Quasars are a type Active Galactic Nucleus, which is compact center galaxy. galaxy that contains Nucleus plays an important part in their luminosity, as elliptical galaxies have much Nuclei spiral galaxies. reason form because contai...