Star Formation Rate and Normalization
of Stellar Populations

We have assumed a constant in time star formation rate and the total
number of stars in the Galaxy,
, to be such that the total mass of the galaxy is
; assuming the Salpeter mass function
, we get

where
stands for the minimum possible mass of the main sequence star. With
,
and
, we obtain
2.6
stars in such a galaxy. This number agrees with a standard estimation of
the galactic star formation rate of order of
per year. In each run of calculations, we trace the evolution of
binaries with initial parameters randomly distributed according to the
chosen initial laws. The evolution of each binary is calculated until either
it comes to the stage where both components remain unchanged (say, double
BH or BH with NS in a wide enough orbit that the orbital evolution due
to the GR can be neglected), or until the time of evolution reaches a maximum
value,
yr.

We calculate the total number of systems,
, passed through a given evolutionary stage ``i'', and calculate
the sum of the stage durations,
. Then the total number of systems
at the given evolutionary stage simultaneously existing in the Milky Way
is estimated as

The number of the initial binaries was taken high enough (typically
1 million each run) to produce a significant statistics (
) for every stage of interest.