2000ApJ...530L..25K

We consider possible evolutionary models for SS 433. We assume that common envelope evolution is avoided if radiation pressure is able to expel most of a super-Eddington accretion flow from a region smaller than the accretor's Roche lobe. This condition is satisfied, at least initially, for largely radiative donors with masses in the range 4-12 M_☉. For donors more massive than about 5 M_☉, moderate mass ratios q=M₂/M₁≳1 are indicated, thus tending to favor black hole accretors. For lower mass donors, evolutionary considerations do not distinguish between a neutron star or black hole accretor. In all cases the mass transfer (and mass-loss) rates M{dot}_tr∼7x10^–6 to 4x10^–4 M_☉ _.yr^–1 are much larger than the likely mass-loss rate M{dot}_jet∼10^–6 M_☉.yr^–1 in the precessing jets. Almost all of the transferred mass is expelled at radii considerably larger than the jet acceleration region, producing the ``stationary'' Hα line and the infrared luminosity and accounting for the low X-ray luminosity.