Optically thick super-Eddington winds in Galactic superluminal sources

A model of major ejection events in Galactic superluminal sources GRO J 165 5-40 and GRS 1915-105 is proposed, in which episodes of e(-)e(+) pair creat ion give rise to the formation of optically thick outflows accelerating pro tons to the limiting Lorentz factor of order 2-3. Probable source of e(-)e( +) pairs is pion production in nucleon collisions. Subsequent deceleration of ejecta and formation of radio jets is analyzed in detail within a shock deceleration model. The detailed data available for GRO J 1655-40 are shown to be in good agreement with proposed scenario.