The Las Campanas Observatory and Anglo–Australian Telescope Rich Cluster Survey ( LARCS ) is a panoramic imaging and spectroscopic survey of an X-ray luminosity-selected sample of 21 clusters of galaxies at 0.07 < z < 0.16 .
CCD imaging was obtained in B and R of typically 2-degree wide regions centred on the 21 clusters , and the galaxy sample selected from the imaging is being used for an on-going spectroscopic survey of the clusters with the 2dF spectrograph on the Anglo-Australian Telescope .
This paper presents the reduction of the imaging data and the photometric analysis used in the survey .
Based on an overlapping area of 12.3 square degrees , we compare the CCD-based LARCS catalogue with the photographic-based galaxy catalogue used for the input to the 2dF Galaxy Redshift Survey ( 2dFGRS ) from the Automated Plate Measuring Machine ( APM ) to the completeness of the GRS/APM catalogue , b _ { J } = 19.45 .
This comparison confirms the reliability of the photometry across our mosaics and between the clusters in our survey .
This comparison also provides useful information about the properties of the GRS/APM .
The stellar contamination in the GRS/APM galaxy catalogue is confirmed to be around 5–10 percent , as originally estimated .
However , using the superior sensitivity and spatial resolution in the LARCS survey we find evidence for four distinct populations of galaxies that are systematically omitted from the GRS/APM catalogue .
The characteristics of the ‘ missing ’ galaxy populations are described , reasons for their absence examined and the impact they will have on the conclusions drawn from the 2dF Galaxy Redshift Survey are discussed .