Quantify the dependence of gamma-ray detectability on red-supergiant wind velocity

Evaluate quantitatively how the red-supergiant wind velocity affects gamma-ray flux and detectability by performing self-consistent kinetic-magnetohydrodynamic simulations that account for its effects on circumstellar density, cosmic-ray acceleration, magnetic-field amplification, and free-free cooling.

Background

The circumstellar density depends on the red-supergiant wind velocity, but changing that velocity in a self-consistent model also changes cosmic-ray acceleration, magnetic-field amplification, and free-free cooling. Consequently, the gamma-ray flux cannot be reliably inferred by applying a simple density rescaling to the fiducial model. The paper identifies dedicated kinetic-magnetohydrodynamic simulations with different wind velocities as necessary for resolving this dependence.

References

Therefore, the dependence of the gamma-ray flux and detectability on $v_{\rm wind}$ cannot be fully evaluated by a simple density scaling alone. A quantitative evaluation of the wind-velocity dependence requires kinetic-MHD simulations with different values of $v_{\rm wind}$, and is left for future work.

— Detectability of 100 TeV Gamma Rays from PeV Cosmic Rays Accelerated in the Early Phase of a Supernova Shock Wave  (2609.18226 - Nishikawa et al., 16 Sep 2026) in Section Discussion