Аннотация:Extending the population synthesis method to isolated young cooling
white dwarfs we are able to confront our model assumptions with
observations made in ROSAT All-Sky Survey [1]. This allows us to check
model parameters such as evolution of spectra and separation of heavy
elements in DA WD envelopes. It seems like X-ray spectrum temperature of
these objects is given by the formula [2] TX-ray = min(Teff,Tmax). We
have obtained DA WD's birth rate and upper limit of the X-ray spectrum
temperature: DA birth rate = 0.61{\times}10$^{-12}$
pc$^{-3}$yr$^{-1}$, Tmax = 4.1{\times}10$^{4}$ K. These
values are in good correspondence with values obtained by [3, 2]. From
this fact we also conclude that our population synthesis method is
applicable to the population of close-by isolated cooling white dwarfs
as well as to the population of the isolated cooling neutron stars.