We have discovered an obscured active galaxy at redshift z = 1.246 identified with the ROSAT X-ray source RX J1011.2+5545. We report on multiwavelength observations of this source and discuss its X-ray, optical and radio properties. This is the first X-ray selected, obscured active galaxy at high redshift to be shown to be radio-loud, with a radio counterpart exhibiting a classical double-lobe ...

The co-evolution between supermassive black holes and their environment is most directly traced by the hot atmospheres of dark matter halos. cooling atmosphere supplies central regions with fresh gas, igniting active galactic nuclei (AGN) long duty cycles. Outflows from engine tightly couple surrounding gaseous medium provide dominant heating source preventing runaway carving cavities driving s...

We have discovered a transient X-ray source, RX J1420.4+5334, which displays a ROSAT flux variation of > ∼ 150 between the ROSAT All-Sky-Survey in 1990 and a preceding pointed ROSAT observations in July 1990. Optical observations suggest a non-active galaxy as the only visible counterpart. We therefore tentatively identify RX J1420.4+5334 as a tidal disruption event in a non-active galaxy.

Deep observations of the X-ray Sky have now resolved most of the X-ray Background. Obscured active galaxies are a key component. The obscured objects which dominate at fluxes above 10 −15 erg cm −2 s −1 are discussed and models in which the growth of wind-blowing active nuclei determine both black hole and galaxy mass are presented. The power from accretion is large and can easily influence the...

Dynamical evolution of spiral galaxies is strongly dependent on nonaxisymmetric patterns that develop from gravitational instabilities, either spontaneously or externally triggered. Some evolutionary sequences are described through which a galaxy could possibly concentrate mass and build bulges, how external gas accretion from cosmic filaments could be funneled to the galaxy disks, and intermit...

We investigate the effects of intermittent strong jets from an Active Galactic Nuclei (AGN) of a massive galaxy in the core of a cool core galaxy cluster, on the dynamics and metal distribution of the intra-cluster medium (ICM). We use a simple model for the metal distribution within the host galaxy which includes metal injection via star formation. We carry out 2D axisymmetric hydrodynamic sim...