Abstract
A method used to test the isotropy of H(0) is proposed and applied to a sample of 132 quasars (whose emission redshift is neither less than 0.2 nor greater than 3.5) which are selected by their radio index. Generalized Hubble moduli (HM) are computed for each object by incorporating q(0), color, galactic extinction, and K-correction so that HM becomes an individual measure of H(0). Upper limits for a possible hemispheric anisotropy for H(0) at very large distances are plus 34 percent and minus 25 percent. Nevertheless, the observed anisotropy is near the 50 percent level of confidence without any consideration of its direction and it appears that HM is minimum in the general direction of the center of the Local Supercluster. The dependence of HM on supergalactic latitude is shown to be consistent with supergalactic extinction, but no conclusion is made since both a considerable amount of dispersion in the data and a large extinction intensity value would first be needed.