Abstract
Studying of solar ionizing environment for the interstellar plasma
inside the heliosphere is an unavoidable aspect of the interpretation of
the full solar cycle of IBEX observations. We present a recent revision
of the observation-based model of the ionization rates inside the
heliosphere discussed by Sokół et al. 2020 (ApJ 897:179). The solar wind
(SW) and the extreme ultraviolet (EUV) radiation affect fluxes of
interstellar atoms inside the heliosphere both in time and in space. We
present a Sun–Heliosphere Observation-based Ionization Rates (SHOIR)
model based on the SW and EUV data available in solar cycle 24. We
revised the in-ecliptic variation of the SW parameters, the latitudinal
structure of the SW speed and density, and the photoionization rates.
The revision most affects the SW out of the ecliptic plane during solar
maximum and the estimate of the photoionization rates, the latter
because of a change of the reference data. The changes are not constant
and vary in time and in latitude. Our study shows that the polar SW is
slower and denser during the solar maximum of solar cycle 24, and that
the current estimates of the total ionization rates are higher than the
previous ones for H, O, and Ne, and lower for He. The changes for the
in-ecliptic total ionization rates are less than 10% for H and He, up
to 20% for O, and up to 35% for Ne compared to the previous estimates.