Temporal variation of the IBEX Ribbon

Abstract:

We present a study of the time variation over half a solar cycle of the ENA flux composing the IBEX Ribbon, with the goal of determining how closely the Ribbon's temporal variation matches that of the adjacent globally distributed ENA flux (GDF). A high degree of similarity implies that the Ribbon flux originates in the same heliospheric regions as the GDF, presumably the inner heliosheath. If the Ribbon flux shows a separate time history, then it likely originates elsewhere, possibly in the outer heliosheath or beyond. Determining the source region places strong constraints on Ribbon formation theories. Prior Ribbon studies have either treated the Ribbon and the GDF as static over the mission, or have not attempted to separate the GDF from the Ribbon when looking at time variation.