A lower limit on the pair density ratio (z+) in an electron‐positron pair wind

We derive a constraint on the pair density ratio, z+=n+/np in an electron‐positron pair wind flowing away from the central region of an accretion disk around a compact object under the assumption of a coupling between electrons, positrons, and protons. The observed annihilation flux per unit volume is used to determine a minimum mass loss rate per unit area, M*, for a given pair density ratio at the base of the streamline. The requirement that M*