Neutral atom distributions in the direction of the ribbon from global simulations

The mysterious ribbon of enhanced energetic neutral atom (ENA) flux observed by NASA's IBEX mission continues to confound modelers. Consensus is growing around so-called "secondary ENA" models, though the exact physics involved is still open to debate. In this poster I will present our latest results from an investigation of the neutral atom properties along a line of sight towards the ribbon near the nose of the heliosphere, based on our MHD-neutral modeling that treats neutral Hydrogen as particles. In addition to the usual moment properties, we present a breakdown according to source region, and show the phase-space distributions that would result if all primary ENAs (i.e. those from the heliosphere) were ionized. To facilitate modeling of the pick-up ions that give rise to secondary ENAs, we present fitting functions to their phase-space distributions.