Related papers: Modeling the Color Magnitude Relation for Galaxy C…
We discuss how the centres of galaxy clusters evolve in time, showing the results of a series of direct N-body simulations. In particular, we followed the evolution of a galaxy cluster with a mass $M_{clus} \simeq 10^{14} $M$_{\odot}$ in…
By means of high-resolution N-body simulations in a LambdaCDM cosmology, we verify that scaling relations similar to those observed for nearby galaxy clusters are also defined by their dark matter hosts; the slopes, however, are not the…
Metallicity distributions (MDs) of globular clusters (GCs) provide crucial clues for the assembly and star formation history of their host galaxies. GC colors, when GCs are old, have been used as a proxy of GC metallicities. Bimodal GC…
Two recent empirical developments in the study of extragalactic globular cluster (GC) populations are the color-magnitude relation of the blue GCs (the "blue tilt") and the nonlinearity of the dependence of optical GC colors on metallicity.…
We measure the number of companions per galaxy (Nc) as a function of r-band absolute magnitude for both the Sloan Digital Sky Survey and the Croton et al. (2006) semi-analytic catalog applied to the Millennium Run simulation. For close…
We investigate a one-zone chemophotometric evolution model of disk-disk galaxy mergers in order to clarify whether or not galaxy mergers with the widely spread merging epoch can reproduce reasonably well the observed small scatter of the…
We investigated the optical properties of 7 clusters of galaxies observed in three colors over the range of absolute magnitudes -24 < M < -12. Our aim is to estimate the Luminosity Function and the total cluster luminosity of our sample in…
We model the galaxy formation in a series of high-resolution N-body simulations using the semi-analytical approach. Unlike many earlier investigations based on semi-analytical models, we make use of the subhalos resolved in the $N$-body…
We study a sample of 19 galaxy clusters in the redshift range $0.15<z<0.30$ with highly complete spectroscopic membership catalogues (to $K < K^{\ast}(\rm z)+1.5$) from the Arizona Cluster Redshift Survey (ACReS); individual weak-lensing…
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…
(Abridged) We present a photometric investigation of the variation in galaxy colour with environment in 11 X-ray luminous clusters at 0.07<z<0.16 taken from the Las Campanas/AAT Rich Cluster Survey. We study the properties of the galaxy…
Some early-type galaxies show a correlation between color and integrated magnitude among the brighter metal-poor globular clusters (GCs). This phenomenon, known as the blue tilt, implies a mass-metallicity relationship among these clusters.…
The nature of the starburst phenomenon in galaxies is investigated using a narrow band color system designed to study color evolution in distant clusters. Work on zero redshift, luminous far-IR galaxies, calibrated by starburst models,…
Color-Magnitude Diagrams (CMDs) are plots that compare the magnitudes (luminosities) of stars in different wavelengths of light (colors). High nonlinear correlations among the mass, color, and surface temperature of newly formed stars…
Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. The basic properties of cluster mergers and their…
Laboratory experiments, large-scale computer simulations and observational cosmology have begun to make progress in the campaign to identify the particle responsible for gravitationally-inferred dark matter. In this contribution we discuss…
Like early-type galaxies, also nearby galaxy clusters define a Fundamental Plane, a luminosity-radius, and a luminosity-velocity dispersion relations, whose physical origin is still unclear. By means of high resolution N--body simulations…
We investigate the luminosity-temperature ($L$-$T$) relation of galaxy clusters as a probe for testing modified gravity (MG) theories, focusing on $f(R)$ gravity and symmetron models. Using an improved semi-analytic framework that…
Context. Sheen and collaborators recently found that a surprisingly large portion (38%) of massive early-type galaxies in heavy clusters show strong merger-related disturbed features. This contradicts the general understanding that massive…
The optical color distributions of globular clusters (GCs) in most large elliptical galaxies are bimodal. Based on the assumed linear relationship between GC colors and their metallicities, the bimodality has been taken as evidence of two…