Related papers: The Optical Green Valley vs Mid-IR Canyon in Compa…

The evolution of galaxies is significantly influenced by the environments they inhabit. While high-density regions, such as clusters of galaxies have been widely studied, the dynamics and quenching processes in intermediate environments…

This thesis work is devoted to the analysis of compact star forming regions (knots) in a representative sample of 32 (U)LIRGs. The project is based mainly on optical high angular resolution images taken with the ACS and WFPC2 cameras on…

The massive cluster of galaxies Abell 2219 (z = 0.228) was observed at 14.3 $\mu$m with the Infrared Space Observatory and results were published by Barvainis et al. (1999). These observations have been reanalyzed using a method…

We have carried out a joint photometric and structural analysis of red sequence galaxies in four clusters at a mean redshift of z ~ 1.25 using optical and near-IR HST imaging reaching to at least 3 magnitudes fainter than $M^*$. As…

We identify nearby disk galaxies with optical structural parameters similar to those of intermediate-redshift compact blue galaxies. By comparing HI and optical emission-line widths, we show that the optical widths substantially…

The nature of Compact Groups (CGs) is investigated by comparing the luminosities and morphologies of CG galaxies, CG Neighbours and Isolated galaxies. CGs turn out to include more early type galaxies than Isolated galaxies and fewer…

We use deep and wide near infrared (NIR) imaging from the Palomar telescope combined with DEEP2 spectroscopy and Hubble Space Telescope (HST) and Chandra Space Telescope imaging to investigate the nature of galaxies that are red in NIR…

Mid-infrared (MIR) imaging and spectroscopic observations are presented for a well defined sample of eight closely interacting (CLO) pairs of spiral galaxies that have overlapping disks and show enhanced far-infrared (FIR) emission. The…

Near-infrared (NIR) K' images of a sample of five low surface brightness disc galaxies (LSBGs) were combined with optical data, with the aim of constraining their star formation histories. Both red and blue LSBGs were imaged to enable…

Compact groups (CGs) of galaxies are extreme environments for morphological transformations and the cessation of star formation. Though initially considered isolated, it is now recognised that many CGs are embedded in larger structures. We…

Compact groups (CGs) provide an environment in which interactions between galaxies and with the intra-group medium enable and accelerate galaxy transitions from actively star forming to quiescent. Galaxies in transition from active to…

We investigate the hypothesis that compact high-velocity clouds (CHVC) are the "missing" dwarf galaxies of the Local Group, by searching them for populations of resolved stars. To this end we conducted two distinct tests based on optical…

We have recently extracted a catalog of compact groups of galaxies (CGs) from the Las Campanas Redshift Survey. This catalog of Las Campanas Compact Groups (LCCGs) contains 76 CGs with a median redshift of z_med = 0.08. The physical…

We describe the results of observations of galaxy clusters conducted with ISOCAM on-board the Infrared Space Observatory. Our research is aimed at understanding the processes driving galaxy evolution in dense environments, free from the…

We have studied the environmental effect on optical-NIR color gradients of 273 nearby elliptical galaxies. Color gradient is a good tool to study the evolutionary history of elliptical galaxies, since the steepness of the color gradient…

(Abridged) This work explores the existence of high redshift massive galaxies unveiled with Spitzer+IRAC, but missed by conventional selection techniques based on optical and near-infrared observations. To this end, we use the…

Massive compact galaxies seem to be more common at high redshift than in the local universe, especially in denser environments. To investigate the fate of such massive galaxies identified at z~2 we analyse the evolution of their properties…

We use a large sample of galaxies drawn from the Sloan Digital Sky Survey (SDSS) and Two Micro All Sky Survey (2MASS) to present Color-Magnitude Relations (CMRs) for late-type galaxies in both optical and optical-infrared bands. A sample…

We present a new method to classify galaxies from large surveys like the Sloan Digital Sky Survey using inclination-corrected concentration, inclination-corrected location on the color-magnitude diagram, and apparent axis ratio. Explicitly…

From a search of a ~ 2400 square degree region covered by both the SDSS and UKIDSS databases, we have attempted to identify galaxies at z ~ 0.5 that are consistent with their being essentially unmodified examples of the luminous passive…