Global Observations of the Interstellar Interaction from the Interstellar Boundary Explorer (IBEX)

TLDR

The Sun’s supersonic solar wind carves a heliosphere as it moves through the local interstellar medium. IBEX mapped the heliosphere’s boundary by imaging energetic neutral atoms across the sky. IBEX revealed an unexpected bright ribbon of ENA emission, aligned with the local interstellar magnetic field and modulated by solar wind and motion, showing the galactic environment strongly imprints the heliosphere.

Abstract

The Sun moves through the local interstellar medium, continuously emitting ionized, supersonic solar wind plasma and carving out a cavity in interstellar space called the heliosphere. The recently launched Interstellar Boundary Explorer (IBEX) spacecraft has completed its first all-sky maps of the interstellar interaction at the edge of the heliosphere by imaging energetic neutral atoms (ENAs) emanating from this region. We found a bright ribbon of ENA emission, unpredicted by prior models or theories, that may be ordered by the local interstellar magnetic field interacting with the heliosphere. This ribbon is superposed on globally distributed flux variations ordered by both the solar wind structure and the direction of motion through the interstellar medium. Our results indicate that the external galactic environment strongly imprints the heliosphere.