  We simulated the signal due to neutral He atoms, observed by Interstellar
Boundary Explorer (IBEX), assuming that charge exchange collisions between
neutral He atoms and He+ ions operate everywhere between the heliopause and a
distant source region in the local interstellar cloud, where the neutral and
charged components are in thermal equilibrium. We simulated several test cases
of the plasma flow within the outer heliosheath and investigated the signal
generation for plasma flows both in the absence and in the presence of the
interstellar magnetic field. We found that a signal in the portion of IBEX data
identified as due to the Warm Breeze does not arise when a homogeneous plasma
flow in front of the heliopause is assumed, but it appears immediately when any
reasonable disturbance in its flow due to the presence of the heliosphere is
assumed. We obtained a good qualitative agreement between the data selected for
comparison and the simulations for a model flow with the velocity vector of the
unperturbed gas and the direction and intensity of magnetic field adopted from
recent determinations. We conclude that direct-sampling observations of neutral
He atoms at 1~AU from the Sun are a sensitive tool for investigating the flow
of interstellar matter in the outer heliosheath, that the Warm Breeze is indeed
the secondary population of interstellar helium, as it was hypothesized
earlier, and that the WB signal is consistent with the heliosphere distorted
from axial symmetry by the interstellar magnetic field.
