| Summary: | The number density and correlation function of galaxies are two key quantities to
characterize the distribution of the observed galaxy population. High- z spectroscopic surveys, which usually involve complex
target selection and are incomplete in redshift sampling, present both
opportunities and challenges to measure these quantities reliably in the
high- z Universe. Using realistic mock
catalogs, we show that target selection and redshift incompleteness can lead to
significantly biased results, especially due to the flux-limit selection
criteria. We develop a new method to correct the flux-limit effect, using
information provided by the parent photometric data from which the spectroscopic
sample is constructed. Our tests using realistic mock samples show that the
method is able to reproduce the true stellar mass function and correlation
function reliably. Mock catalogs are constructed for the existing zCOSMOS and
VIPERS surveys, as well as for the forthcoming Prime Focus Spectrograph (PFS)
galaxy evolution survey. The same set of mock samples are used to quantify the
total variance expected for different sample sizes. We find that the total
variance decreases very slowly when the survey area reaches about 4
deg ^2 for the abundance and about 8 deg ^2 for the
clustering, indicating that the cosmic variance is no longer the dominant source
of error for PFS-like surveys. We also quantify the improvements expected in the
PFS-like galaxy survey relative to zCOSMOS and VIPERS surveys.
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