The CFHT north Galactic pole faint galaxy survey

Abstract

view Abstract Citations (26) References (48) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The CFHT North Galactic Pole Faint Galaxy Survey Infante, L. ; Pritchet, C. J. Abstract As part of a study of large-scale structure at intermediate redshifts, a catalog of faint galaxies has been derived for a 2.2 deg^2^ area (maximum angular extent ~2.5^deg^ X 2.5^deg^) near the north Galactic pole. The photometric and astrometric calibration methods for the catalog are described in detail; the data comprising the catalog are found to be complete to limiting magnitudes J ~ 24 and F ~ 23. Galaxy counts and color distributions have been obtained from the catalog. A logarithmic slope of d(log N)/dm = 0.45 was derived for the J bandpass over the magnitude interval 20 <= J <= 24 whereas d(log N)/dm = 0.37 for the F bandpass (19 <= F <= 23); these results are in good agreement with previous work. These slopes are determined primarily by the counts at the faintest magnitudes; brighter than J~22.5 and F~21.5 the logarithmic slope of the counts is 0.40 in both bands, consistent with the constant mean color that is observed for such galaxies. There is a dramatic difference in the slope of the J and F counts fainter than J ~22.5 and F ~ 21.5. It is shown that this must imply a change in the properties (number count slope or mean color) of fainter galaxies relative to those at J <~ 22, and cannot be due solely to the presence of a new population of faint blue objects. The galaxy counts in this catalog match almost perfectly onto counts over the range 15 <~ J <~ 20 from the APM survey by Maddox and collaborators, and onto the faint CCD counts by Lilly et al. and Tyson at J ~> 23. These three data sets therefore provide a well defined mean relation for galaxy counts in the J bandpass. No significant variations are seen in the mean number density of galaxies over our fields. This constraint requires that the extent of large-scale inhomogeneities ("sheets") in the galaxy distribution across the line of sight must be larger than ~25 h_100_^-1^ Mpc-in reasonable accord with observations of large-scale structure in the CfA survey. Publication: The Astrophysical Journal Supplement Series Pub Date: December 1992 DOI: 10.1086/191736 Bibcode: 1992ApJS...83..237I Keywords: Astrometry; Astronomical Photometry; Galactic Clusters; Red Shift; Sky Surveys (Astronomy); Astronomical Catalogs; Charge Coupled Devices; Galactic Evolution; Astronomy; GALAXIES: CLUSTERING; GALAXIES: PHOTOMETRY; GALAXIES: DISTANCES AND REDSHIFTS; SURVEYS full text sources ADS |