Dr. Antonio (Toni) Marin Franch has visited the UCM to parcipate as referee in the PhD defense of Esther Mármol Queraltó. The day after that event Toni has given a seminar entitled "Relative ages of Galactic globular clusters. Clues to the Milky Way formation time scales".

In the seminar Toni has shown how the ACS Survey of Galactic Globular Clusters, which is a Hubble Space Telescope Treasury program, has provided an excellent, large, deep and homogeneous photometric globular cluster database. Based on observations from this program, he has measured precise relative ages for a sample of 64 Galactic globular clusters. The analysis of the data has revealed that the Galactic globular cluster sample can be divided into two groups: a population of old clusters with an age dispersion of 5% and no age-metallicity relation, and a group of younger clusters with an ge-metallicity relation similar to that of the globular clusters associated with the Sagittarius dwarf galaxy. He discussed these results in the context of the Milky Way formation mechanisms and time scales.

More pictures at 2009_01_14_AMarinFranch.