ASTRONOMICAL IMAGES AND DATA MINING IN THE INTERNATIONAL VIRTUAL OBSERVATORY CONTEXT

In the past ten years, the concept of Virtual Observatory (VObs) has increasingly gained importance in the domain of astrophysics, as a way of seamlessly accessing data in different wavelength domains stored in digital archives. There are many reasons why the VObs is useful for the development of science: to monitor time variability of phenomena, to compare phenomena in different bands, to increase return for investment (by fostering data re -use for scientific, educational and outreach purposes), to perform statistical analysis and mining on large quantities of data. The International Virtual Observatory Alliance (IVOA) has paved the way for the VObs to become a really useful tool for the scientific community, by promoting standards, by defining data interoperability methods, by fostering the needed coordination among data providers. But the VObs is more than just archives and standards: it is also infrastructure, basic software tools, advanced applications, evolution of methods and techniques, cross-fertilization with other communities. Discovering information in wide-field images and mining large archives are key items towards the use of the VObs as a tool for developing science. Data mining, or knowledge discovery in databases, while being the main methodology to extract the scientific information contained in Massive Data Sets (MDS), needs to tackle crucial problems since it has to orchestrate complex challenges posed by transparent access to different computing environments, scalability of algorithms, reusability of resources. To achieve a leap forward for the progress of astrophysics in the data avalanche era, the community needs to implement an infrastructure capable of performing data access, processing and mining in a distributed but integrated context.