OVERVIEW
With an age up to 13.5 Gyr, only 0.3 Gyrs less than the present estimate for the age of the Universe, globular clusters (GCs) are the oldest easily dateable local Galactic fossils. They are among the main bricks of the assembling of galactic halos and bulges and their stellar population properties are at the basis of synthesis models, essential to our ability to interpret the light from distant galaxies. GCs are a benchmark for cosmology and for stellar structure and evolution theory, and represent an ideal laboratory to understand star formation and chemical enrichment in the primordial Universe.
The advent of space telescopes and ground-based 10-m size telescopes provided us with a huge amount of observational data, spanning the range of wavelengths from radio to X-rays. The development of astrometric techniques, and the availability of multifiber high resolution spectrographs allows astrometry and observational kinematics, with radial velocities and proper motions, both from the ground and with
HST, measured for up to hundred of thousands of stars per cluster. Large-field imaging cameras now routinely provide photometric data for up to a few hundred thousand stars per cluster.
HST and interferometric techniques provide a deep view in the very center of dense stellar systems. A complete inventory of photometric and kinematics properties, from X-ray to near-infrared, of GC stars in any evolutionary stage, and from the very center to the outskirts of clusters is now a reality. An increasing number of catalogs of photometric and kinematics (proper motions and radial velocities) are now available on the Web.
The Web pages of the Padova GC Group have the main purpose of updating on the work in progress at the Physics and Astronomy Department of the University of Padova, and of providing the astronomical community with the
photometric databases (both from ground-based and space observations) that we are building within the projects on GC kinematics and stellar population we are involved in.
- HST LARGE PROJECTS
- GROUND-BASED PROJECTS