The Origin of High Energy Solar Gamma Radiation

by Prof. James M. Ryan (U. New Hampshire)

Friday Jan 20, 2023, 3:30 PM → 5:00 PM Pacific/Honolulu

112 (Watanabe Hall)

For almost forty years, the Sun has been known to emit GeV photons for hours on end, following some comparatively “short-lived” solar flares.  The radiation is clearly of hadronic origin, but how, when and where the progenitor solar protons are created or accelerated and how they are transported to the Sun to radiate constitutes a set of thorny questions.  We review the observations in several data channels and the disparate interpretations and models and how the redeployment of a neutron monitor on Haleakala can contribute to the resolution of the controversy.

 

Dr. Ryan has been in the business of cosmic rays, solar physics and gamma-ray astronomy since the 1970s.  He was a Co-Investigator on the Solar Maximum Mission and the UNH Principal Investigator on the COMPTEL experiment on the Compton Observatory.  He is PI on the UNH neutron monitor program and has developed a number of neutron imaging instruments for solar and terrestrial physics and domestic applications.  He was the chair of the Division of Astrophysics and is an APS Fellow.

Video - Prof. J. Ryan