Related papers: Some Integrated Properties of Galactic Globular Cl…
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…
As the largest gravitationally collapsed objects, and as objects with a relatively low space density, clusters of galaxies offer one of the best sets of standard candles for trying to measure basic cosmological parameters such as the…
We present Hubble Space Telescope ACS/WFC and WFC3/UVIS imaging for a sample of 50 low surface brightness (LSB) galaxies in the $\sim$10$^{15}$ M$_{\odot}$ Perseus cluster, which were originally identified in ground-based imaging. We…
Combined observations from UV to IR wavelengths are necessary to fully account for the star-formation in galaxy clusters. Low mass (log M/Msun<10) galaxies are typically not individualy detected, particularly at higher redshifts (z~1-2)…
We analyse the photometric, chemical, star formation history and structural properties of the brightest globular cluster (GC) in M81, referred as GC1 in this work, with the intention of establishing its nature and origin. We find that it is…
We have obtained deep photometry of NGC 1199 (in the compact group HCG 22) and NGC 6868 (in the Telescopium loose group) with the Keck II and the VLT-I telescopes. Both galaxies are the optically brightest galaxy of their groups. NGC 1199…
We have identified 335 galaxy cluster and group candidates, 106 of which are at z > 1, using a 4.5 um selected sample of objects from a 7.25 deg^2 region in the Spitzer Infrared Array Camera (IRAC) Shallow Survey. Clusters were identified…
We report the discovery of a probable new globular cluster in the disk of the Milky Way. Visible in 2MASS and the GLIMPSE survey, it has an estimated foreground extinction of A_V ~ 24 mag. The absolute magnitude of the cluster and the…
In the last decade, a new kind of stellar systems has been established that shows properties in between those of globular clusters (GCs) and early-type dwarf galaxies. These so-called ultra-compact dwarf galaxies (UCDs) have masses in the…
Tidally limited star clusters are started on nearly circular orbits in the dark matter sub-halos present at high redshift and evolved with an n-body code augmented with gravitational interactions in the clusters. The tidally removed stars…
The composite galaxy luminosity function (hereafter LF) of 39 Abell clusters of galaxies is derived by computing the statistical excess of galaxy counts in the cluster direction with respect to control fields. Due to the wide field coverage…
We define here a standard candle to determine the distance of clusters of galaxies and to investigate their peculiar velocities by using the n^{th} rank galaxy (magnitude m$_n$). We address the question of the universality of the luminosity…
Clusters of galaxies are self-gravitating systems of mass ~10^14-10^15 Msun. They consist of dark matter (~80 %), hot diffuse intracluster plasma (< 20 %) and a small fraction of stars, dust, and cold gas, mostly locked in galaxies. In most…
We acquired spectra for a random sample of galaxies within a 0.83 square degree region centered on the core of the Centaurus cluster. Radial velocities were obtained for 225 galaxies to limiting magnitudes of V < 19.5. Of the galaxies for…
We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation (epsilon >…
We present new deep photometry of the rich globular cluster (GC) systems around the Brightest Cluster Galaxies UGC 9799 (Abell 2052) and UGC 10143 (Abell 2147), obtained with the HST ACS and WFC3 cameras. For comparison, we also present new…
The relaxation time at the half-mass radius of Galactic globular clusters (GGCs) is typically within a few Gyr. Hence, the majority of GGCs are expected to be well relaxed systems, given their age is around 12-13 Gyr. So any initial radial…
We have observed 433 z<=0.08 brightest cluster galaxies (BCGs) in a full-sky survey of Abell clusters. The BCG Hubble diagram is consistent to within 2% of a Omega_m=0.3, Lambda=0.7 Hubble relation. The L_m-alpha relation for BCGs, which…
Recent observations of globular clusters in intermediate-age (2-4 Gyr old) merger remnants have provided the hitherto `missing link' between between young merger remnants and normal elliptical galaxies. The luminosity functions (LFs) of the…
Using Magellan/IMACS images covering a 1.2 x 1.2 sq. degree FOV with seeing of 0.4"-0.6", we have applied convolution techniques to analyse the light distribution of 364 confirmed globular cluster in the field of NGC 5128 and to obtain…