Cygnus X-3 Revisited: 10 Years of Muon and Radio Observations

Abstract

The Soudan 2 deep underground tracking calorimeter has recorded cosmic ray muon tracks from the direction of the galactic x-ray binary Cygnus X-3 on most transits during the interval 1989-1998. We analyze these events in the context of previous reports of Cygnus X-3-related muon flux during major radio flares of that source. We find some evidence for excess flux during a small number of transits coincident with major radio flares. We also find an indication that these events may be distributed around the source with a Gaussian point spread function with $\sigma =1.3^{\circ }$, larger than the instrumental angular spread of $\le 0.3^{\circ }$, verified by observation of the shadow of the moon.