The Kapteyn Institute at the University of Groningen is the chief center for the development of data handling techniques for OmegaCAM/VST. Much technical and scientific work is going into defining not only surveys to be done with the VST, but also the system with which the data may be calibrated, processed, analyzed, filtered and archived. A key functionality of the system will be to allow users at other sites to access and manipulate the VST data archive. This work towards a Virtual Observatory fits very naturally into a project such as this. Other imaging data will be linked to this database as it becomes available through a `federation' of other European data centers. A link-up with spectral surveys would be a tremendous enhancement.
The main cosmological interests for the exploitation of the VST and VISTA at the Institute lie in the fields of gravitational lensing, of large-scale structure and cluster studies, and of searches for qso's and supernovae. In addition Groningen has a long track record in the study of the local universe, which is expected to continue with these new survey facilities. The local universe forms a crucial boundary condition on any cosmological model!
The Kapteyn Institute is a node of the FP5-TMR LENSNET network, which concentrated on weak gravitational lensing. Over the past few years we have/have had three postdocs, two staff members, one Phd and one undergraduate student working on weak lensing projects. This activity continues to be an important one at the institute, and is now geared to exploiting data from the ESO Wide-Field Imager and preparing for VST and VISTA. On-going variability searches at Groningen, particularly in the field of microlensing, are yielding many tools with which variables can be identified automatically from a time-series of exposures, even in very crowded regions (Sackett, Kuijken). These techniques can also be applied to the search for supernovae, which will be a major application of the VST archive.
Multi-colour QSO surveying is being carried out by Barthel, on the basis of red wide-field imaging data from ESO and CTIO.
The Kapteyn Institute is a friendly, interactive department with a rich history in astronomy. It provides a fertile ground for the training of young researchers.