Galaxy disc central surface brightness distribution in the optical and
  near-infrared bands
  To study the disc central surface brightness ($\mu_0$) distribution in
optical and near-infrared bands, we select 708 disc-dominated galaxies within a
fixed distance of 57 Mpc from SDSS DR7 and UKIDSS DR10. Then we fit $\mu_0$
distribution by using single and double Gaussian profiles with an optimal bin
size for the final sample of 538 galaxies in optical $griz$ bands and
near-infrared $YJHK$ bands.
  Among the 8 bands, we find that $\mu_{0}$ distribution in optical bands can
not be much better fitted with double Gaussian profiles. However, for all the
near-infrared bands, the evidence of being better fitted by using double
Gaussian profiles is positive. Especially for $K$ band, the evidence of a
double Gaussian profile being better than a single Gaussian profile for
$\mu_{0}$ distribution is very strong, the reliability of which can be approved
by 1000 times test for our sample. No dust extinction correction is applied.
The difference of $\mu_{0}$ distribution between optical and near-infrared
bands could be caused by the effect of dust extinction in optical bands. Due to
the sample selection criteria, our sample is not absolutely complete. However,
the sample incompleteness does not change the double Gaussian distribution of
$\mu_{0}$ in $K$ band. Furthermore, we discuss some possible reasons for the
fitting results of $\mu_{0}$ distribution in $K$ band. Conclusively, the double
Gaussian distribution of $\mu_{0}$ in $K$ band for our sample may depend on
bulge-to-disk ratio, color and disk scalelength, rather than the inclination of
sample galaxies, bin size and statistical fluctuations.
