CORRELATION-ANALYSIS OF FAINT GALAXIES
Abstract
As part of a larger study of the clustering properties of galaxies at intermediate redshifts, we present a study of methods and algorithms used to estimate the angular correlation function, omega(theta), of faint galaxies. A technique has been developed which permits the reliable measurement of omega(theta) at amplitude levels as low as approximately 0.002 for fields of area approximately 2 deg2 - i.e. to separations of order 1 degree for galaxies with a blue magnitude almost-equal-to +24. An iterative method has been used to compute the best mean density that ensures consistency between the integral constraint and omega(theta). Artificial galaxy catalogues with built in correlation functions have been analyzed to test for the presence of spurious correlations associated with, for example, field geometry. We conclude that the amplitude and power-law exponent of omega(theta), as well as any outer cutoffs or breaks in omega(theta), are all reliably determined by our algorithm for separations theta less than or similar to 1 degree in catalogues whose angular extent is approximately 2 deg2.
Description
Keywords
LARGE SCALE STRUCTURE OF UNIVERSE, COSMOLOGY, OBSERVATIONS, METHODS, DATA ANALYSIS, GALAXIES, CLUSTERING