Today, great observatories around the world, devote a substantial amount of observing time to sky surveys. The resulted images are inputs of source finder modules. These modules search for the target objects and provide us with source catalogues. We sought to quantify the ability of detection tools in recovering faint galaxies regularly encountered in deep surveys. Our approach was based on com...

A visual search has been made of four fields using United Kingdom 1.2m Schmidt Objective Prism plates with a reciprocal dispersion of 1 180 A/mm at HP. Such plate material is ideally suited to searches for emission-line galaxies. We present a catalogue of 53 emission-line objects, which comprises 45 galaxies, where individual HI1 regions are resolved in 16 bright galaxies; 8 are emission li...

We review the variety of Active Galactic Nuclei (AGN) classes (so-calledAGN zoo") and classification schemes of galaxies by activity types based on their optical emission-line spectrum, as well as other parameters and other than optical wave-length ranges. A historical overview of discoveries of various types of active galaxies is given, including Seyfert galaxies, radio galaxies, QSOs, BL Lace...

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

it is inferred from the symmetrical and luminous x-ray emission of fossil groups that they are mature, relaxed galaxy systems. cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (bggs), the central early-t...

We present a comparison of barstrength Qb and circumnuclear dust morphology for 75 galaxies in order to investigate how bars affect the centers of galaxies. We trace the circumnuclear dust morphology and amount of dust structure with structure maps generated from visible-wavelength HST data, finding that tightly wound nuclear dust spirals are primarily found in weakly barred galaxies. While str...

We have found the stellar populations of early-type galaxies are homogeneous with no significant difference in color or Mg2 index, despite the dichotomy between X-ray extended early-type galaxies and X-ray compact ones. Since the X-ray properties reflect the potential gravitational structure and hence the process of galaxy formation, the homogeneity of the stellar populations implies that the f...

The parsec scale properties of low power radio galaxies are reviewed here, using the available data on 12 FR I galaxies. The most frequent radio structure is an asymmetric parsec-scale morphology, i.e. core and one-sided jet. It is shared by 9 (possibly 10) of the 12 mapped radio galaxies. One (possibly 2) of the other galaxies has (have) a two-sided jet emission. Two sources are known from pub...