<i>Fermi</i>LARGE AREA TELESCOPE OBSERVATIONS OF BLAZAR 3C 279 OCCULTATIONS BY THE SUN

Observations of occultations of bright <i>γ</i>-ray sources by the Sun may reveal predicted pair halos around blazars and<i>/</i>or new physics, such as, e.g., hypothetical light dark matter particles-axions. We use <i>Fermi Gamma-Ray Space Telescope</i> (<i>Fermi</i>) data to analyze four occultations of blazar 3C 279 by the Sun on October 8 each year from 2008 to 2011. A combined analysis of the observations of these occultations allows a point-like source at the position of 3C 279 to be detected with significance of ≈3<i>σ</i>, but does not reveal any significant excess over the flux expected from the quiescent Sun. The likelihood ratio test rules out complete transparency of the Sun to the blazar <i>γ</i>-ray emission at a 3<i>σ</i> confidence level.