Antimatter sources E flux sensitivity

We provide parametric limits as a function of the closest antistar mass, velocity, and surrounding matter density. We also employ a novel Monte~Carlo method to set limits for a few hypotheses about the antistar population. For a population with properties equivalent to those of regular stars concentrated in the Galactic disk we obtain f_bar*_<2.5x10^-6^ at 95% confidence level, which is 20 times more constraining than limits previously available.

For a primordial population of antistars distributed in the Galactic halo we obtain new local upper limits which decrease as a function of antistar mass M from f_bar*_<0.2 at 95% confidence level for M=1M_{sun}_ to f_bar*_<1.6x10^-4^ at 95% confidence level for M=10M_{sun}_. By combining these limits with existing microlensing constraints for lighter objects in the Magellanic clouds, we infer that a primordial population of halo antistars must have a density lower than O (10^-5^pc^-3^) to O (10^-2^pc^-3^) depending on their masses.

Our limits can constrain models for the origin and propagation of antinuclei in cosmic rays.