Microstructure of the Heliospheric Termination Shock: Implications for Energetic Neutral Atom Observations

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

15

Acceleration Of Particles, Ism: Atoms, Plasmas, Shock Waves, Stars: Winds, Outflows

Scientific paper

The Voyager 2 plasma observations of the proton distribution function downstream of the quasi-perpendicular heliospheric termination shock (TS) showed that upstream thermal solar wind ions played little role in the shock dissipation mechanism, being essentially transmitted directly through the shock. Instead, the hot supra-thermal pickup ion (PUI) component is most likely responsible for the dissipation at the TS. Consequently, the downstream proton distribution function will be a complicated superposition of relatively cool thermal solar wind protons and hot PUIs that have experienced either direct transmission or reflection at the TS cross-shock potential. We develop a simple model for the TS microstructure that allows us to construct approximate proton distribution functions for the inner heliosheath. The distribution function models are compared to κ-distributions, showing the correspondence between the two. Since the interpretation of energetic neutral atom (ENA) fluxes measured at 1 AU by IBEX will depend sensitively on the form of the underlying proton distribution function, we use a three-dimensional MHD-kinetic global model to model ENA spectra at 1 AU and ENA skymaps across the IBEX energy range. We consider both solar minimum and solar maximum-like global models, showing how ENA skymap structure can be related to global heliospheric structure. We suggest that the ENA spectra may allow us to probe the directly the microphysics of the TS, while the ENA skymaps reveal heliospheric structure and, at certain energies, are distinctly different during solar minimum and maximum.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Microstructure of the Heliospheric Termination Shock: Implications for Energetic Neutral Atom Observations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Microstructure of the Heliospheric Termination Shock: Implications for Energetic Neutral Atom Observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microstructure of the Heliospheric Termination Shock: Implications for Energetic Neutral Atom Observations will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1888938

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.