:: The Virtual Observatory as a Semantic and a Computational Grid

Roy Williams
California Institute of Technology
co-Director, US National Virtual Observatory

Data and computing are becoming essential tools in astronomy, and archive-based research is growing, especially through federation of different datasets. The Virtual Observatory movement is represented through many national initiatives, coordinated through an international alliance (ivoa.net), and first fruits are appearing.
Diversity of data sources is tackled by setting up a flexible registry structure, by standards for data representation, by standard abstract web services, and by a semantically meaningful controlled vocabulary.
For bulk data, massive computation is needed for mining and for making derivative data products; an example of the latter is multi-wavelength image stacking. The Atlasmaker project is building a virtual data pipeline on Teragrid to facilitate research in this new view of the Universe.