TeV Solar Gamma Rays as a Probe for the Solar Internetwork Magnetic Fields

Recently, solar gamma rays produced by cosmic rays interacting with the solar atmosphere have been detected in the GeV to TeV energy range, revealing that cosmic rays are significantly affected by magnetic fields in the solar atmosphere. However, much of the observations remain unexplained by existing physical models. Using a semianalytic model, we demonstrate that magnetic fields at and below the photosphere with a large horizontal component could account for the approximately 1 TeV solar gamma rays observed by HAWC. This suggests that high-energy solar gamma rays could serve as a novel probe for magnetic fields beneath the photosphere, which in the future could help improve the understanding of solar magnetism, the key driver of space weather.