Related papers: HST proper motions in Galactic globular clusters

Because of their unique quality, Hubble Space Telescope (HST) data have played an important complementary role in studies of infrared (IR) galaxies conducted with major facilities, as VLT or Spitzer, and will be as well very valuable for…

We investigate the stellar and dynamical mass profiles in the centres of 25 brightest cluster galaxies (BCGs) at redshifts of 0.05 $\leq z \leq$ 0.30. Our spectroscopy enables us to robustly measure the Gauss-Hermite higher order velocity…

With a high value of heliocentric radial velocity, a retrograde orbit, and being suspected to have an extragalactic origin, NGC 3201 is an interesting globular cluster for kinematical studies. Our purpose is to calculate the relative proper…

We present the first high-precision proper motion catalog, tied to the International Celestial Reference System (ICRS), of infrared astrometric reference stars within R $\leq$ 25" (1 pc) of the central supermassive black hole at the…

Multi-epoch observations with ACS on HST provide a unique and comprehensive probe of stellar dynamics within NGC 6397. We are able to confront analytic models of the globular cluster with the observed stellar proper motions. The measured…

The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters is providing a major breakthrough in our knowledge of Globular Clusters (GCs) and their stellar populations. Among the main results, we discovered that all the…

Several observational studies have shown that many Galactic globular clusters (GCs) are characterised by internal rotation. Theoretical studies of the dynamical evolution of rotating clusters have predicted that, during their long-term…

We use the HB morphology of 48 Galactic GCs to study the radial distributions of the different stellar populations known to exist in globular clusters. Assuming that the (extremely) blue HB stars correspond to stars enriched in Helium and…

Globular clusters are collisional systems, meaning that the stars inside them interact on timescales much shorter than the age of the Universe. These frequent interactions transfer energy between stars and set up observable trends that tell…

We have measured the absolute proper motions of globular clusters NGC 6397, NGC 6626 (M 22) and NGC 6656 (M 28) as part of our ongoing Southern Proper-Motion Program. The reference system is the ICRS via Hipparcos stars for these three low…

NGC 6809 is a luminous metal-poor halo globular cluster that is relatively easy to study due to its proximity and low concentration. Because of its high Galactic latitude (b = -23deg), interstellar reddening and contamination is not very…

We discuss some of the key open questions regarding the formation and evolution of globular clusters (GCs) during galaxy formation and assembly within a cosmological framework. The current state-of-the-art for both observations and…

Observed mass-to-light ratios (M/L) of metal-rich globular clusters (GCs) disagree with theoretical predictions. This discrepancy is of fundamental importance since stellar population models provide the stellar masses that underpin most of…

We recently used a large set of Monte Carlo simulations of globular clusters (GCs) to define new fully empirical parameters (named A5, P5, and S2.5) able to trace the internal dynamical evolution of dense stellar systems. These parameters…

We probe the evolution of globular clusters that could form in giant molecular clouds within high-redshift galaxies. Numerical simulations demonstrate that the large and dense enough gas clouds assemble naturally in current hierarchical…

If a planetary nebula (PN) is shown to be a member of a star cluster, we obtain important new constraints on the mass and chemical composition of the PN's progenitor star, which cannot be determined for PNe in the field. Cluster membership…

We present a comparison between the observational data on the kinematical structure of G1 in M31, obtained with the Hubble WFPC2 and STIS instruments, and the results of dynamical simulations carried out using the special-purpose computer…

Absolute proper motions for six new globular clusters have recently been determined. This motivated us to obtain the Galactic orbits of these six clusters both in an axisymmetric Galactic potential and in a barred potential, such as the one…

We have derived a new photographic photometry and proper motions for 20000 stars with completeness to V = 18 in the direction of galactic center at the intermediate latitude (l = 3 deg,b = 47 deg; alpha(1950)=15h 18m, delta(1950) = +02deg…

We present the first results from our HST Brightest Cluster Galaxy (BCG) survey of seven central supergiant cluster galaxies and their globular cluster (GC) systems. We measure a total of 48000 GCs in all seven galaxies, representing the…