Energetic neutral atoms from the heliosheath as an additional population of neutral hydrogen in the inner heliosphere. (arXiv:1811.09064v1 [astro-ph.SR])

Energetic neutral atoms from the heliosheath as an additional population of neutral hydrogen in the inner heliosphere. (arXiv:1811.09064v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bzowski_M/0/1/0/all/0/1">M. Bzowski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Galli_A/0/1/0/all/0/1">A. Galli</a>

Interstellar neutral hydrogen (ISN H) gas penetrates freely the heliopause.
Inside the inner heliosheath, the charge-exchange interaction of this gas with
the shocked solar wind and pickup ions creates energetic neutral atoms (ENAs).
ISN H is strongly depleted inside the termination shock but a fraction reaches
the Earth’s orbit. In these regions of the heliosphere, ISN H is the source
population for interstellar pickup ions and for the heliospheric backscatter
glow. The Globally Distributed Flux (GDF) of ENAs created in the inner
heliosheath has been sampled directly by Interstellar Boundary Explorer (IBEX).
Based on these measurements, we calculate the density of the GDF ENA population
at the Earth’s orbit. We find that this number density is between $10^{-4}$ and
$10^{-3}$ cm$^{-3}$, i.e., comparable in magnitude to the number density of ISN
H in the downwind portion of the Earth’s orbit. Half of this atom population
have energies less than $sim 80$ eV. This GDF population of neutral hydrogen
is likely to provide a significant contribution to the intensity of
heliospheric glow in the downwind hemisphere, may be the source of the inner
source of hydrogen pickup ions, and may be responsible for the excess of
production of pickup ions found in the analysis of magnetic wave events induced
by the proton pickup process in the downwind region at 1 au from the Sun.

Interstellar neutral hydrogen (ISN H) gas penetrates freely the heliopause.
Inside the inner heliosheath, the charge-exchange interaction of this gas with
the shocked solar wind and pickup ions creates energetic neutral atoms (ENAs).
ISN H is strongly depleted inside the termination shock but a fraction reaches
the Earth’s orbit. In these regions of the heliosphere, ISN H is the source
population for interstellar pickup ions and for the heliospheric backscatter
glow. The Globally Distributed Flux (GDF) of ENAs created in the inner
heliosheath has been sampled directly by Interstellar Boundary Explorer (IBEX).
Based on these measurements, we calculate the density of the GDF ENA population
at the Earth’s orbit. We find that this number density is between $10^{-4}$ and
$10^{-3}$ cm$^{-3}$, i.e., comparable in magnitude to the number density of ISN
H in the downwind portion of the Earth’s orbit. Half of this atom population
have energies less than $sim 80$ eV. This GDF population of neutral hydrogen
is likely to provide a significant contribution to the intensity of
heliospheric glow in the downwind hemisphere, may be the source of the inner
source of hydrogen pickup ions, and may be responsible for the excess of
production of pickup ions found in the analysis of magnetic wave events induced
by the proton pickup process in the downwind region at 1 au from the Sun.

http://arxiv.org/icons/sfx.gif