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 6×6 arcmin 2 fields targeted at QSOs with redshifts 0.5<z<2 and seven 28×13 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′∼19.5 mag and J∼21 mag , sufficiently deep to detect passively evolving systems up to a redshift of z≲1.5 and luminosity of 0.5 L *. The optical data reach a depth of roughly R∼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≲z≲1.5 for evolutionary studies and follow‐up observations.