Smoothing the redshift distributions of random samples for the baryon
  acoustic oscillations : applications to the SDSS-III BOSS DR12 and QPM mock
  samples
  We investigate the impact of different redshift distributions of random
samples on the baryon acoustic oscillations (BAO) measurements of
$D_V(z)r_\mathrm{d}^\mathrm{fid}/r_\mathrm{d}$ from the two-point correlation
functions (2PCF) of galaxies in the Data Release 12 (DR12) of the Baryon
Oscillation Spectroscopic Survey (BOSS). Big surveys, such as BOSS, usually
assign redshifts to the random samples by randomly drawing values from the
measured redshift distributions of the data, which would necessarily introduce
fiducial signals of fluctuations into the random samples, weakening the signals
of BAO, if the cosmic variance cannot be ignored. We propose a smooth function
of redshift distribution that fits the data well to populate the random galaxy
samples. The resulting cosmological parameters match the input parameters of
the mock catalogue very well. The significance of BAO signals has been improved
by $0.33\sigma$ for a low-redshift (LOWZ) sample and by $0.03\sigma$ for a
constant-stellar-mass (CMASS) sample, though the absolute values do not change
significantly. Given the precision of the measurements of current cosmological
parameters, it would be appreciated for the future improvements on the
measurements of galaxy clustering.
