My main research interests are in galaxy evolution and dynamics, with emphasis on what can be learned from the nearby Universe, and in particular from our own Galaxy. The assembly process of a galaxy leaves imprints in the present-day spatial distribution, motions, ages and chemical abundances of its stars. The Milky Way is the only system (for now) for which we have direct access to this information, because only in our Galaxy and its nearby satellites can we measure the properties of millions of individual stars. One of the main goals of my research has been to characterize these fossil signatures from a theoretical point of view, and to use observational data to recover those fossils and thereby reconstruct the formation history of our Galaxy.  

The recently launched European Space Agency’s satellite, Gaia, is currently measuring accurately the spatial distribution, kinematics and properties of a billion stars in the Milky Way. This unparalleled new dataset is allowing us to address the most fundamental questions about our Galaxy’s history and dynamics. With the revolutionary new understanding of a typical galaxy like ours that Gaia is already delivering, we are obtaining unique insights on the process of galaxy formation and on the nature and role of dark matter, two of the most urgent open questions in modern Astrophysics. 

My group’s research presently covers three areas: the merger history of the Galaxy (combining kinematics and chemistry); the dynamics of the different Galactic components, including the halo and the disk with the aim of constraining the spatial distribution and granularity of dark matter, and the kinematics and dynamics of globular clusters and dwarf galaxies. We are currently also strongly involved in Gaia’s data validation work, and in two new multi-object spectrographs: WEAVE on the WHT (La Palma) and 4most on VISTA (ESO, Chile).