TITLE:  Remote Sensing of the Properties and the Structure of the Outer Heliosheath

ABSTRACT:  The dynamics, the structure, and the interplay of the physical processes in and outside of the heliosphere are largely unknown. The IBEX spacecraft has delivered unprecedented data that allow us to investigate these unexplored regions. The IBEX spacecraft consists of two single pixel cameras remotely probing the heliospheric boundaries by measuring neutral atoms at Earth’s orbit. While the IBEX-Hi camera covers the high energy range, the IBEX-Lo camera covers the lower energy range but allows species identification.  Both cameras provide us with sky maps “painted” by neutrals originating from interstellar space.  Due to the Sun’s motion relative to the interstellar medium (ISM), the ISM plasma is deflected around the heliosphere that is an obstacle for interstellar plasma. Neutral atoms can enter the heliosphere, but some undergo charge-exchange between perturbed ISM plasma particles and ISM neutral atoms outside of the heliopause (secondary population).  While interstellar neutrals provide information on the interstellar medium, neutrals that were created by charge-exchange carry information of the deflected plasma because these neutrals were originally part of deflected interstellar plasma. From these neutral particle distributions, therefore, we can determine the flow velocity and temperature. With the help of analytic considerations and numerical models we may be able to address the flow pattern around the heliosphere and its shape.  In this talk I discuss current approaches to address the structure of the outer heliopause and the results obtained.