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 measure the galaxy clustering
accurately. 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 2PCFs), the Vmax method and
the "shuffled" method. We found that the shuffled method significantly
underestimates both of the projected 2PCFs and the two-dimensional 2PCFs in
redshift space. While the Vmax method does not show any notable bias on the
2PCFs for volume-limited samples. For flux-limited 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.
