Stellar flares cannot explain the Galactic 511 keV emission

Saurabh Mittal, Thomas Siegert, Francesca Calore +12

The origin of the 511 keV line signal in the Milky Way remains unresolved despite decades of observations. The measured flux of $\sim 3 \times 10^{-3}\,\mathrm{ph\,cm^{-2}\,s^{-1}}…