Related papers: Omega Centauri as a Disrupted Dwarf Galaxy: Eviden…
[Abridged] Detailed chemical tagging of individual stellar populations in the Galactic globular cluster (GC) NGC 1851 is presented. Abundances are derived from FLAMES spectra for the largest sample of giants (124) ever analysed in this…
Recent observations for the color-magnitude diagrams (CMDs) of the massive globular cluster Omega Centauri have shown that it has a striking double main sequence (MS), with a minority population of bluer and fainter MS well separated from a…
We find a deficiency of binary stars moving on strongly retrograde Galactic orbits. No binary deficiencies are seen for U or W velocities, however. From theoretical analyses, we rule out preferential disruption of pre-existing binary stars…
We simulate the result of orbital decay for a dwarf satellite galaxy in a disk galaxy potential. The peeling-off of the satellite by the strong tidal field within the disk of the host galaxy quickly reduces the satellite's mass, and…
We have investigated whether or not a tidal stripping scenario can reproduce the observed surface-brightness profile of omega Centauri using N-body simulations. Assuming that the progenitor of omega Centauri is a dwarf elliptical galaxy, we…
We take advantage of the exquisite quality of the Hubble Space Telescope 26-filter astro-photometric catalog of the core of Omega Cen presented in the first paper of this series and the empirical differential-reddening correction presented…
We present the observational properties of the dwarf galaxy population (Mr > M*+1) corresponding to one of the largest samples of spectroscopically confirmed galaxy cluster members reported in the literature. We have observed that red dwarf…
Three fields located close to the center of the globular cluster Omega Cen were surveyed in a search for variable stars. We present V-band light curves for 32 periodic variables. This sample includes 10 SX Phe stars, 19 eclipsing binaries,…
In this paper we present the analysis of Hubble Space Telescope (HST) observations of the globular cluster Omega Centauri. Our analysis combines data obtained in this work with previously published HST data from an earlier article of this…
Recent stellar populations and chemical abundance studies point to an accreted origin of omega Cen. In this light, and given the retrograde, small size orbit of omega Cen, we search for a kinematical signature left by bits hypothetical…
The formation of populous secondary star cluster systems is a widespread phenomenon in mergers of gas-rich galaxies. Many, if not most, of those clusters are massive and compact enough to be young globular clusters (GCs). GC systems in most…
Recently, new Sagittarius (Sgr) dwarf galaxy globular clusters were discovered, which opens the question on the actual size of the Sgr globular cluster population, and therefore on our understanding of the Sgr galaxy formation and accretion…
We present deep CCD photometry of a field in the newly discovered dwarf spheroidal galaxy in Sagittarius (hereafter Sgr), and of a nearby control field. These data (totaling ~3.5 hrs exposure time in V and I) were used to produce…
This paper explores if, and to what an extent, the stellar populations of early type galaxies can be traced through the colour distribution of their globular cluster systems. The analysis, based on a galaxy sample from the Virgo ACS data,…
Context. The fraction of field binaries on retrograde orbits about the Milky Way is significantly lower compared to its prograde counterpart. Chemical and dynamical evidence suggests that the retrograde stellar population originates from…
Numerical simulations of dwarf spheroidal galaxies undergoing several close encounters with the Milky Way are described. By comparing our models to observed properties of the recently discovered dwarf galaxy in Sagittarius (Sgr), we discuss…
The globular cluster omega Centauri contains the largest known population of very hot horizontal branch (HB) stars. We have used the Hubble Space Telescope to obtain a far-UV/optical color-magnitude diagram of three fields in omega Cen. We…
The photometric study of the Sagittarius dwarf galaxy by Marconi et al (1998) has suggested the presence of a spread in metallicity (-0.7< [Fe/H] < -1.6), which may result from different bursts of star formation. We present the results from…
We present a suite of extragalactic explorations of the origins and nature of globular clusters (GCs) and ultra-compact dwarfs (UCDs), and the connections between them. An example of GC metallicity bimodality is shown to reflect underlying,…
We present a quantitative comparison between the Horizontal Branch morphology in the core of the Sagittarius dwarf spheroidal galaxy (Sgr) and in a wide field sampling a portion of its tidal stream (Sgr Stream), located tens of kpc away…