Related papers: Formation, Evolution and Properties of Isolated Fi…
High-resolution numerical simulations of galaxy mergers are analysed. The global structure and isophotal shapes of the merger remnants are in good agreement with the observations. Whereas equal-mass mergers lead to anisotropic, boxy…
Intrinsic galaxy alignments constitute the major astrophysical systematic of forthcoming weak gravitational lensing surveys but also yield unique insights into galaxy formation and evolution. We build analytic models for the distribution of…
Elliptical galaxies are the main contributors to the chemical enrichment of the intracluster and intergalactic medium; understanding how they form and evolve enables us to get important hints on the amounts of energy and processed matter…
We present a comprehensive analysis of the stellar population properties (age, metallicity and the alpha-element enhancement [E/Fe]) and morphologies of red-sequence galaxies in 24 clusters and groups from z~0.75 to z~0.45. The dataset,…
We present N-body simulations of elliptical galaxy encounters into dry mergers to study the resulting unbound intergalactic stellar population, in particular that of the post-Main Sequence stars. The systems studied are pairs of spherical…
It is now well known that certain massive galaxies undergo enormous enhancements in their SFR when they undergo major mergers(100x). To analyse the SF enhancement and AGN fraction evolution during the merger process, we use a more…
Elliptical galaxies larger than 10 pixels in the Hubble Ultra Deep Field (UDF) were surveyed for internal structure; 30 out of 100 in a sample of 884 morphologically classified galaxies exhibit large blue clumps near their centers.…
We present a semi-analytical model in which galaxy collisions and strong tidal interactions, both in the field and during the collapse phase of groups and clusters help determine galaxy morphology. From a semi-analytical analysis based on…
We study the dominant central giant elliptical galaxies in ``Fossil groups'' using deep optical (R-band) and near infrared (Ks-band) photometry. These galaxies are as luminous as the brightest cluster galaxies (BCGs), raising immediate…
We present a deep broadband optical imaging study of a complete sample of luminous elliptical galaxies (M_B<-20) at distances 15 Mpc - 50 Mpc, selected from the Tully catalog of nearby galaxies. The images are flat to ~0.35% across the 20'…
We study the evolution of the red and blue galaxies from $z=3$ to $z=0$ using the EAGLE simulation. The galaxies in the blue cloud and the red sequence are separated at each redshift using a scheme based on Otsu's method. Our analysis shows…
We present a structural analysis of 138 compact elliptical galaxies (cEs) in the redshift range of $z < 0.05$ using the Sloan Digital Sky Survey (SDSS) DR12 data. We perform single- and double-component S\'ersic model fitting to their SDSS…
We study the colour-magnitude relation (CMR) for a sample of 172 morphologically-classified E/S0 cluster galaxies from the ESO Distant Cluster Survey (EDisCS) at 0.4<z<0.8. The intrinsic colour scatter about the CMR is very small (0.076) in…
Two-dimensional surface photometry has been done for 166 {\em early-type} galaxies (bulge/total luminosity $B/T>0.6$) in 3 fields of the Canadian Network for Observational Cosmology (CNOC) cluster survey. These galaxies are either…
This thesis presents observational studies of evolution of dwarf elliptical galaxies. dE's are numerically dominant population in clusters of galaxies, but their origin and evolution is a matter of debate. Several scenarios of gas removal…
By combining new long-slit spectral data obtained with the Southern African Large Telescope (SALT) for 9 galaxies with previously published our observations for additional 12 galaxies we study the stellar and gaseous kinematics as well as…
The morphological properties of galaxies between $21 {\rm~mag} < I < 25 {\rm~mag}$ in the {\em Hubble Deep Field} are investigated using a quantitative classification system based on measurements of the central concentration and asymmetry…
The properties of isolated galaxies are mainly driven by intrinsic evolution and not by the external influence of their environments. Therefore the isolated galaxy sample may be considered as a reference sample to study different…
The excess numbers of blue galaxies at faint magnitudes are a long-standing cosmological puzzle. We present new number-magnitude counts as a function of galactic morphology from the first deep fields of the Cycle 4 Hubble Space Telescope…
We calculate the colours and luminosities of redshift z = 0.1 galaxies from the EAGLE simulation suite using the GALAXEV population synthesis models. We take into account obscuration by dust in birth clouds and diffuse ISM using a…