Energetic particles beyond the heliospheric shock: Anomalous Cosmic Rays (ACRs), Pick-Up Ions (PUIs) and the associated energetic neutral atoms (ENAs)

The Voyager 1 spacecraft is expected to encounter the heliospheric termination shock within the next decade. Besides the ongoing discussion how to possibly predict the time of this encounter, there is a growing interest into a more detailed description of the region beyond the heliospheric shock, i.e., the heliosheath. Refinements of the so far rather crude models will facilitate interpretation of forthcoming data. We report on results obtained with our model of the transport of ACRs in the heliosheath. In improvement of earlier approaches it is based on a solar wind background flow computed with a self-consistent large-scale model of the heliosphere. Besides these downstream ACR spectra, which will become accessible for in situ observation as soon as the Voyager spacecraft will have crossed the heliospheric shock, we study the potential of observations of the flux of ENAs to remotely explore the structure of the heliosheath. In particular, as part of a comparison of the various ENA sources, we will address the significance of the contribution of those ENAs resulting from a de-charging of PUIs