Galactic model parameters of cataclysmic variables: Results from a new
  absolute magnitude calibration with 2MASS and WISE
  In order to determine the spatial distribution, Galactic model parameters and
luminosity function of cataclysmic variables (CVs), a $J$-band magnitude
limited sample of 263 CVs has been established using a newly constructed
period-luminosity-colours (PLCs) relation which includes $J$, $K_{s}$ and
$W1$-band magnitudes in 2MASS and WISE photometries, and the orbital periods of
the systems. This CV sample is assumed to be homogeneous regarding to distances
as the new PLCs relation is calibrated with new or re-measured trigonometric
parallaxes. Our analysis shows that the scaleheight of CVs is increasing
towards shorter periods, although selection effects for the periods shorter
than 2.25 h dramatically decrease the scaleheight: the scaleheight of the
systems increases from 192 pc to 326 pc as the orbital period decreases from 12
to 2.25h. The $z$-distribution of all CVs in the sample is well fitted by an
exponential function with a scaleheight of 213$^{+11}_{-10}$ pc. However, we
suggest that the scaleheight of CVs in the Solar vicinity should be $\sim$300
pc and that the scaleheights derived using the sech$^2$ function should be also
considered in the population synthesis models. The space density of CVs in the
Solar vicinity is found 5.58(1.35)$\times 10^{-6}$ pc$^{-3}$ which is in the
range of previously derived space densities and not in agreement with the
predictions of the population models. The analysis based on the comparisons of
the luminosity function of white dwarfs with the luminosity function of CVs in
this study show that the best fits are obtained by dividing the luminosity
functions of white dwarfs by a factor of 350-450.
