We propose to conduct a deep wide field imaging survey to cover 25 sq.deg. down to a depth equivalent to I = 25 (in a 3" aperture, at 5), in UBVRI, with the current and upcoming large mosaic CCD arrays. The core survey, a three color study of the full 25 sq.deg., can be done in ~70 nigths with the CFH12k camera.
The science goals are numerous, including deep galaxy surveys aimed at the identification of very high redshift galaxies (z > 3), a better understanding of the clustering properties of galaxies and their luminosity function at z ~ 1, and to search for distant clusters of galaxies and QSOs. In addition, the catalogs produced will serve as the basis for further studies with the VLT and Gemini.
The CFH12k camera can be used to cover this large area in BVI in about 70 nights at CFHT, very competitive vs. other facilities. We propose with S. Lilly a joint French-Canadian survey over 4 semesters, involving the communities in the definition of the science goals and strategy of the survey, broadening as much as possible the scientific scope to capitalize on the huge database. We intend to release the data to the community as soon as it is processed.
A follow up in 2 other colors will be carried out with Megacam. Infrared JK wide field imaging would be a superb complement to the dataset. While we will propose to image part of the area with the upcoming 1K imager, we strongly suggest the manufacturing of a wide field IR camera at CFHT.