Towards a reliable star formation history of the galactic disk in the Gaia era

International audienceA new tool is being developed to derive the star formation and chemical enrichment history of the galactic disc through comparison of future Gaia data with synthetic color magnitude diagrams. First steps are being conducted joining two powerful algorithms: IAC-pop/MinnIAC, a code that has widely and very successfully being applied to external galaxies, and the new version of the Besançon Galaxy Model, which allows a good control of the Initial Mass Function, the Star Formation History and the chemical enrichment. A first tuning of these algorithms to the main characteristics of the Gaia data is described, emphasizing the role of the accurate parallaxes, the astrometric and photometric uncertainties and the Gaia observational constraints of the Gaia data. Preliminary tests demonstrate that the methodology proposed here has huge capabilities, although ingredients such as the stellar evolutionary models are critical in the process. The strategy to incorporate higher complexity in the process is discussed