Virtual Observatory and Astronomical Datacenters 

Much of modern astronomical research involves the accumulation of huge amounts of digitized data. The handling of these enormous data sets, often by distributed communities, requires innovative modeling and new abstractions of the information content. Astronomical surveys are often global efforts requiring collaborators in many places to share, validate and combine processed data and derived results.

The Kapteyn Astronomical Institute houses the OmegaCEN astronomical wide-field imaging data center which bundles expertise in astronomical information technology. The OmegaCEN staff undertakes research and development programs to create more efficient data lineage, mining and analysis systems which allow researchers to scientifically exploit previously unmanageable volumes of data. The staff and PhD research projects focus on the interface between astronomy and information technology, such as

• Virtual Observatory
• data visualization
• scalable archiving and processing
• extreme data lineage via backward/forward linking
• federation of databases and computing power
• GRID computing technologies and infrastructures

For optical wide field imagers (such as the OmegaCAM panoramic camera) advanced data analysis techniques are developed at OmegaCEN, for example in:

• flat fielding
• global astrometry
• surface brightness photometry
• structural analysis
• image restoration using shapelets

OmegaCEN has built and operates the Astro-WISE advanced survey system.

Astro-WISE stands for Astronomical Wide-field Imaging System for Europe. It is an e-Science information system providing a European-wide federated environment in which very large datasets from optical (see also the OmegaCAM panoramic camera in the research area Instrumentation), infrared and radio imagers can be processed, scientifically exploited, published and archived. Research groups in various European countries collaborate directly via the Astro-WISE information system on research projects that for example

• trace dark matter and dark energy
• detect the morphological transitions in galaxy evolution
• find the first light and galaxies in the very early Universe
• unravel the history of our Milky Way
• detect extrasolar planets

OmegaCEN is partner in the European Virtual Observatory (Euro-VO) Data Center Alliance (DCA, an EU FP6 programme) and Astronomical Infrastructure for Data Access programme (AIDA, an EU FP7 programme). The concept of a Virtual Observatory is that all the world's astronomical data should feel like it sits on the astronomer's desk top, analysable with a user selected workbench of tools and made available through standard interfaces across the whole range of astronomical research topics. The European Virtual Observatory aims at unifying the digital data collections of European astronomy, integrating their access mechanisms with evolving e-technologies, and enhancing the science extracted from these datasets.

For the Lofar radio telecope OmegaCEN connects the Lofar archives to the Euro-VO (DCA) and provides the expertise for designing a massive multi-Petabyte archive with direct user access (SNN-BSIK). OmegaCEN is as a Virtual Organization connected to the EGEE Grid.

Various collaborations with Computational Science groups are on-going, such as the University's Donald Smits Center for Information Technology (Target project), the Articificial Intelligence and Cognitive Engineering institute (Professor Schomaker, "Script Googling", see the KdK@Astro-WISE project) and the Institute for Mathematics and Computing Science for developing visualization techniques of multi-dimensional data (Professor Roerdink, AstroVIS)

Staff active in the area of astronomical information technology: Valentijn, van der Hulst , Peletier, Boxhoorn, Begeman and Verdoes Kleijn. Their webpages contain more detailed information on the specific research topics.