  We study the behaviour of shocked wind-electrons leaving wind-driving stars
after undergoing the outer wind termination shock. As an example, we describe
the evolution of the keV-energetic electron distribution function downstream of
the heliospheric termination shock. We start from a kinetic transport equation
in the bulk frame of the heliosheath plasma flow taking into account
shock-induced electron injection, convective changes, cooling processes, and
whistler wave-induced energy diffusion. From this equation we proceed to an
associated pressure moment of the electron distribution function arriving at a
corresponding pressure transport equation which describes the evolution of the
electron pressure in the bulk frame of the plasma along the plasma flow lines.
We assume that the local distribution function, in view of the prevailing
non-LTE conditions, is represented by a local kappa function with local kappa
parameters that vary with the streamline coordinate $s$ downstream of the solar
wind termination shock. We obtain the solution for the electron pressure as a
function of the streamline coordinate $s$ from the pressure transport equation
and demonstrate that, connected with this pressure, one obtains an expression
for the entropy of the electron fluid which can also be derived as a streamline
function. We show that the heliosheath electron fluid can essentially be
characterized as an isobaric and isentropic flow. These results allow to
generally conclude that astrotail plasma flows are characterized as such flows.
