The living sky and the Gaia Legacy project: hybrid data management, dynamic data modeling, and dedicated data reduction sw for Gaia-like big data exploitation

Gaia Legacy idea born to enhance the platform system of Gaia's Big Data science data center in Turin and to be a center for the management, visualization, processing, manipulation and analysis of large amounts of data that require the development and implementation of innovative systems with exascale approach, guaranteeing high performances. The system responds to the scientific needs of the INAF community beyond the core science of the Gaia mission itself under a multimessenger approach such as characterization of cosmological gravitational waves and degenerate binary systems in the Milky Way. The system will extend its capability to engineering data collected by space instrumentation for studies of future missions, observation calibration and qualification of instrumental models. We present the Gaia Legacy repository project which goal is the generation of a deep and complete sky, on 4π sterad, as a reference tool and therefore interoperable for the integration of multiband data (from radio to high energies) and multimessenger data (e.g. sources of gravitational waves, neutrinos,...) for efficient data mining aimed at fast multidimensional scientific data exploitation.