We present a summary of our recent results on gas outflows in radio galaxies. Fast outflows (up to 2000 km s−1) have been detected both in ionized and neutral gas. The latter is particularly surprising as it shows that, despite the extremely energetic phenomena occurring near an AGN, some of the outflowing gas remains, or becomes again, neutral. These results are giving new and important insigh...

I present a broad overview of modelling of the Narrow Line Region (NLR) of active galaxies, and discuss some of the more recent models we currently have for the emission from the NLR. I show why the emission line ratios from the NLR are constrained to certain observed values, and describe what physical parameters we can derive from observations using emission line models. Also presented are som...

We present the results of a search for high energy extraterrestrial neutrinos with the Baikal underwater Cherenkov detector NT200, based on data taken in 1998 2003. Upper limits on the diffuse fluxes of νe + νμ + ντ , predicted by several models of AGN-like neutrino sources, are derived. For an E−2 behavior of the neutrino Preprint submitted to Elsevier Science 1 September 2005 spectrum, our li...

We describe a new sample of Seyfert nuclei discovered during the course of an optical spectroscopic survey of nearby galaxies. The majority of the objects, many recognized for the first time, have luminosities much lower than those of classical Seyferts and populate the faint end of the AGN luminosity function. A significant fraction of the nuclei emit broad Hα emission qualitatively similar to...

We have discovered a correlation between the X-ray absorbing column densities within Seyfert galaxies and the relative alignment between the central engines and their host galactic disks. This correlation carries several implications for Seyfert unification models. (1) In addition to small-scale circumnuclear absorbers, there are absorbing systems associated with the host galactic plane that ar...

In this paper I summarize the science motivations, as well as a few mid-infrared spectroscopic methods used to identify the principal mechanisms of energy production in dust enshrouded galactic nuclei. The development of the various techniques is briefly discussed. Emphasis is given to the use of the data which are becoming available with the infrared spectrograph (IRS) on Spitzer, as well as t...

This contribution reviews the properties of nuclear activity in nearby galaxies, with emphasis on results obtained from current optical surveys and multiwavelength follow-up observations thereof.

The Chandra X–ray Satellite already observed several deep fields, including the two 1 Megasec exposures of the Chandra Deep Field South (CDFS) and North. We review here the main findings from the CDFS. The LogN–LogS relations show the resolution of the X–ray background into point sources at the level of 83–99% in the 1–2 keV band and 65–98% in the 2–10 keV band, given the uncertainties in the u...