Evidence for a New Component of High-Energy Solar Gamma-Ray Production

Understand

The observed multi-GeV gamma-ray emission from the solar disk --- sourced by hadronic cosmic rays interacting with gas, and affected by complex magnetic fields --- is not understood.

• Utilizing an improved analysis of the Fermi-LAT data that includes the first resolved imaging of the disk, we find strong evidence that this emission is produced by two separate mechanisms.
• Between 2010-2017 (the rise to and fall from solar maximum), the gamma-ray emission is dominated by a polar component.
• Between 2008-2009 (solar minimum) this component remains present, but the total emission is instead dominated by a new equatorial component with a brighter flux and harder spectrum.