Strength of the Termination Shock Inferred from the Globally Distributed Energetic Neutral Atom Flux from IBEX

Abstract In this study, we estimate the heliospheric termination shock (HTS) compression ratio at multiple directions in sky from a quantitative comparison of observed and simulated inner heliosheath (IHS) energetic neutral atom (ENA) fluxes. We use 3D steady-state simulation heliosphere to simulate ENA fluxes by postprocessing MHD plasma using multi-Maxwellian distribution for protons IHS. The are compared with time exposure–averaged IBEX-Hi data first 3 yr mission. is performed calculating fractional difference spectral slope between range ratios, where spectrum varied as function downstream pickup ion temperature ratio. estimated particular direction determined minimum value slope. Our study shows that method close agreement large-scale Voyager 2 its travel direction. Also, other near ecliptic plane similar weakest found be on port side (27°, 15°). This HTS IBEX data.