The Munich near-infrared cluster survey - I. Field selection, object extraction and photometry

The Munich Near-Infrared Cluster Survey (MUNICS) is a wide-area, medium-deep, photometric survey selected in the K' band. It covers an area of roughly 1 deg(2) in the K' and J near-IR passbands. The survey area consists of 16 6 x 6 arcmin(2) fields targeted at QSOs with redshifts 0.5 < z < 2 and seven 28 x 13 arcmin(2) strips targeted at 'random' high Galactic latitude fields. 10 of the QSO fields were additionally imaged in R and I, and 0.6 deg(2) of the randomly selected fields were also imaged in the V, R and I bands. The resulting object catalogues were strictly selected in K', having a limiting magnitude (50 per cent completeness) of K' similar to 19.5 mag and J similar to 21 mag, sufficiently deep to detect passively evolving systems up to a redshift of z less than or similar to 1.5 and luminosity of 0.5L*. The optical data reach a depth of roughly R similar to 23.5 mag.. The main scientific aims of the project are the identification of galaxy clusters at redshifts around unity and the selection of a large sample of field early-type galaxies at 0 < z < 1.5 for evolutionary studies. In this paper-the first in a series-we describe the concept of the survey, the selection of the survey fields, the near-IR and optical imaging and data reduction, object extraction, and the construction of photometric catalogues. Finally, we show the J - K' versus K' colour-magnitude diagram and the R - J versus J - K', V - I versus J - K', and V - I versus V - R colour-colour diagrams for MUNICS objects, together with stellar population synthesis models for different star formation histories, and conclude that the data set presented is suitable for extracting a catalogue of massive field galaxies in the redshift range 0.5 less than or similar to z less than or similar to 1.5 for evolutionary studies and follow-up observations.