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TeV Solar Gamma Rays as a Probe for the Solar Internetwork Magnetic Fields
Kenny C Y Ng1, Andrew Hillier2, Shin'ichiro Ando3,4
1The Chinese University of Hong Kong, Department of Physics, Shatin, New Territories, Hong Kong, China.
Physical Review Letters
|October 5, 2025
Summary
High-energy solar gamma rays detected by HAWC suggest strong magnetic fields beneath the Sun's surface. This finding offers a new way to study solar magnetism and its impact on space weather.
Area of Science:
- * Astrophysics
- * Solar Physics
- * Plasma Physics
Background:
- * Recent detection of GeV to TeV solar gamma rays indicates cosmic rays are influenced by solar atmospheric magnetic fields.
- * Existing physical models struggle to explain these high-energy gamma-ray observations.
- * Solar magnetism is a primary driver of space weather phenomena.
Purpose of the Study:
- * To explain the origin of approximately 1 TeV solar gamma rays observed by the HAWC observatory.
- * To investigate the role of sub-photospheric magnetic fields in solar gamma-ray production.
- * To establish high-energy solar gamma rays as a novel tool for probing solar magnetism.
Main Methods:
- * Development and application of a semianalytic model.
- * Simulation of cosmic ray interactions within the solar atmosphere.
- * Analysis of magnetic field configurations at and below the photosphere.
Main Results:
- * Demonstrated that magnetic fields with a significant horizontal component beneath the photosphere can explain the observed ~1 TeV solar gamma rays.
- * Identified a potential mechanism for the production of high-energy gamma rays.
- * Showed consistency between model predictions and HAWC observations.
Conclusions:
- * Sub-photospheric magnetic fields, particularly those with large horizontal components, are crucial for understanding high-energy solar gamma-ray emission.
- * High-energy solar gamma rays provide a unique opportunity to probe the Sun's hidden magnetic field.
- * This research enhances our understanding of solar magnetism and its influence on space weather.
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