The cross-correlation of the Zwicky and Shane-Wirtanen catalogs of galaxies

The angular positions of 3769 galaxies brighter than 15th mag in three subsets of the Zwicky catalog are cross-correlated with Shane-Wirtanen (SW) galaxy counts in the original 10 x 10 arcmin cells. The cross-correlation function is compared with the autocorrelation function of the high-resolution version of the SW catalog. It is found that the cross-correlation function is given by a power law with an exponent of 1 - gamma, where gamma = 1.81 + or - 0.03, and that the function breaks sharply from the power law at an angular scale of about 2.6 deg. The scale is shown to be similar to the one at which a similar break was discovered in the autocorrelation function of the SW catalog. It is concluded that the break is a local feature rather than a feature intrinsic to the clustering of galaxies and may be explained in terms of clumpy obscuration in the Galaxy with a characteristic scale of about 2 deg.