2006/09/26 by L. F. Olsen, C. Benoist, Christophe Benoıst +12
Mathematics · Physics and Astronomy · #Artificial intelligence #Astronomy and Astrophysical Research #Astrophysics #Cluster (spacecraft) #Computer science #Degree (music) #Filter (signal processing) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Geology #Geometry #Image (mathematics) #Mathematics #Noise (video) #Physics #Radio Astronomy Observations and Technology #Redshift #Scientific Research and Discoveries #Sky #Square (algebra) #Telescope #astro-ph
paper · pdf · doi:10.1051/0004-6361:20066088
15 pages, 15 figures, accepted for publication in A&A, a full resolution copy of the paper can be retrieved from http://www.dark-cosmology.dk/~lisbeth/papers/6088.pdf
arxiv created 2006/09/29 · openalex publication_date 2006/09/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We apply a matched-filter cluster detection algorithm to the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) i-band data for the Deep-1, Deep-2, Deep-3 and Deep-4 fields covering a total of 4square degrees. To test the implemented procedure we carry out simulations for assessing the frequency of noise peaks as well as estimate the recovery efficiency. We estimate that up to z~0.7 the catalogue is essentially complete for clusters of richness class R>~1. The recovered redshifts are in general overestimated by dz=0.1 with a scatter of sigmadz~0.1, except at redshifts z>~1 where the estimated redshifts are systematically underestimated. The constructed cluster candidate catalogue contains 162 detections over an effective area of 3.112 square degrees corresponding to a density of ~52.1 per square degree. The median estimated redshift of the candidates is z=0.6. The estimated noise frequency is 16.9+-5.4 detections per square degree. From visual inspection we identify systems that show a clear concentration of galaxies with similar colour. These systems have a density of ~20 per square degree.