Exploring the "digital Universe"
The unique capabilities and efficiency of the new ground and space-based observatories have led to an unprecedented "data explosion" calling for innovative ways to process, explore and exploit these data. For this purpose, researchers have been obliged to turn to the GRID paradigm of distributed computing and resources to address complex, front-line research problems. Existing astronomical data centres and archives were joined into an interoperating and single unit. This new astronomical data resource has formed an Astrophysical Virtual Observatory (AVO). It is an innovative and evolving system that allows users to interrogate multiple databanks in a transparent way using international standards for data access and mining protocols. It also enables data analysis techniques through a coordinating entity that provides wide-network bandwidth, and state-of-the-art analysis tools. In the AVO, all archives understand the same query language and can be accessed through a uniform interface. Furthermore, diverse data can be analysed using the same tools. The first major scientific discovery to emerge from the AVO was during the demonstrations held at the European Southern Observatory (ESO) in January 2004. More than 30 massive black holes were found, which had previously escaped detection behind masking dust clouds. The paper describing these results has already been accepted and published by the European journal Astronomy & Astrophysics. This is the first refereed scientific paper that has been based on end-to-end use of Virtual Observatory tools, showing that AVO has evolved to become a real research tool. AVO is currently working in conjunction with other international efforts in Europe, North and South America, as well as in the Asia-Pacific region. This is part of an International Virtual Observatory Alliance to define essential new standards and technologies, so that the VO concept can have a global dimension.
