We use deep HST STIS and NICMOS images of three spectroscopically confirmed galaxy counterparts of high-redshift damped Lyα (DLA) absorbers (one of which is a new discovery) to test the hypothesis that high-redshift DLA galaxies are Lyman-break galaxies. If this hypothesis is correct the emission properties of DLA galaxies must lie within the range of emission properties measured for Lyman-brea...

How is the universe organized on large scales? How did this structure evolve from the unknown initial conditions of a rather smooth early universe to the present time? The answers to these questions will shed light on the cosmology we live in, the amount, composition and distribution of matter in the universe, the initial spectrum of density fluctuations that gave rise to this structure, and th...

Close examination of “pseudobulges” in several early-type disk galaxies indicates that they are actually composite structures consisting of both a flattened, kinematically cool disklike structure (“disky pseudobulge”) and a rounder, kinematically hot spheroidal structure (“classical bulge”). This indicates that pseudobulges, thought to form from internal secular evolution, and classical bulges,...

We present high resolution radio observations of the nuclear radio emission in a sample of eight radio galaxies having Megaparsec sizes, using the European VLBI network at 18 cm. At a resolution of 25 mas we detect all the giant radio galaxies from our sample. Among themDA 240 and 1331−099 were imaged for an extended period. These observations reveal a twin-jet structure for DA 240 and one-side...

This review presents a perspective on recent advances in understanding neutral ISM structure in external galaxies. Hi is a fundamental probe of galactic baryonic material, and its structure and distribution offer vital signatures of dynamical and evolutionary processes that drive star formation and galaxy evolution. New, high-resolution Hi data cubes for external galaxies now reveal the feature...

In this second paper dedicated to the study of satellite galaxies we present broad-band photometry in the B, V , R and I filters of 49 satellite galaxies orbiting giant isolated spiral galaxies. First analysis of the properties of these objects are presented by means of color–color and color–magnitude diagrams for earlyand late-type satellites. Although we find differences in the slope of the V...

The Sloan Lens ACS (SLACS) Survey is an efficient Hubble Space Telescope (HST) Snapshot imaging survey for new galaxy-scale strong gravitational lenses. The targeted lens candidates are selected spectroscopically from within the Sloan Digital Sky Survey (SDSS) database of galaxy spectra for having multiple nebular emission lines at a redshift significantly higher than that of the SDSS target ga...

Using the initial peculiar-velocity field, we analytically study the hierarchical formation of gravitationally bound objects. The field is smoothed over a scale that corresponds to the mass of a given class of objects. Through the Zel’dovich approximation, the smoothed field determines how the objects cluster together to form a new class of more massive objects. The standard cosmological parame...

We present two–dimensional slab–jet simulations of jets in inhomogeneous media consisting of a tenuous hot medium populated with a small filling factor by warm, dense clouds. The simulations are relevant to the structure and dynamics of sources such as Gigahertz Peak Spectrum and Compact Steep Spectrum radio galaxies, High Redshift Radio Galaxies and radio galaxies in cooling flows. The jets ar...

We report the detection of a 4 h −1 70 Mpc long large-scale filament leading into the massive galaxy cluster MACS J0717.5+3745. The extent of this object well beyond the cluster's nominal virial radius (∼ 2.3 Mpc) rules out prior interaction between its constituent galaxies and the cluster and makes it a prime candidate for a genuine filament as opposed to a merger remnant or a double cluster. ...