Toward accurate measurement of property-dependent galaxy clustering I.Comparison of the Vmax method and the“shuffled”method

Galaxy clustering provides insightful clues to our understanding of galaxy formation and evolution,as well as the universe.The redshift assignment for the random sample is one of the key steps to accurately measure galaxy clustering.In this paper,by virtue of the mock galaxy catalogs,we investigate the effect of two redshift assignment methods on the measurement of galaxy two-point correlation functions(hereafter 2 PCFs),the Vmax method and the"shuffled"method.We have found that the shuffled method significantly underestimates both of the projected 2 PCFs and the two-dimensional 2 PCFs in redshift space,while the Vmax method does not show any notable bias on the 2 PCFs for volume-limited samples.For fluxlimited samples,the bias produced by the Vmax method is less than half of the shuffled method on large scales.Therefore,we strongly recommend the Vmax method to assign redshifts to random samples in the future galaxy clustering analysis.