Simulating a Dynamic Solar Cycle and Its Effects on the Interstellar Boundary Explorer Ribbon
Monday, 15 December 2014
Over the last 5 years, the Interstellar Boundary EXplorer (IBEX) has made continuous measurements of hydrogen energetic neutral atoms (ENAs) created by the solar wind-local interstellar medium (SW-LISM) interaction. In particular, this includes observations of the IBEX "ribbon," a feature of enhanced flux encircling the sky. With a half solar cycle of observations, IBEX has shown the ribbon is a strong and dynamic feature of the measurements. This suggests a relatively local generation mechanism for the ribbon, such as the "secondary ENA" mechanism, where primary ENAs from inside the heliosphere undergo multiple charge-exchange events outside the heliopause, creating secondary ENAs that may be detected at 1 AU. We will present time-dependent simulation results of IBEX measurements, particularly the ribbon flux simulated using the secondary ENA mechanism. These results are computed by implementing a dynamic solar cycle in our 3D, time-dependent, MHD/kinetic code. We show results of the ribbon flux simulated between 2009 and 2017. While IBEX has provided us with key observations over the past 5 years, future measurements by the Interstellar Mapping and Acceleration Probe (IMAP) will allow us to look at the evolution of the ribbon over an extended period with higher resolution, which may finally enable us to determine the origin of the ribbon.