Statistical significance of a large quasar inhomogeneity in the sky

Abstract

Statistical techniques are devised to study the significance of apparent inhomogeneities in the distribution of points on a spherical surface, especially in the form of jets and chains. The methods are applied to complete samples of radio quasars in specific windows of magnitudes and redshifts. It is found that while most of the distributions studied show very little evidence of non-randomness, the inhomogeneity reported by Arp (1984) is highly significant. There is also some evidence, although a statistically weaker one, for a chainlike structure in the distribution of low redshift quasars in another area of the sky.