Spectral Components of SS 433

Abstract

We present results from new optical and UV spectroscopy of the unusual binary system SS 433, and we discuss the relationship of the particular spectral components we observe to the properties of the binary. (1) The continuum spectrum which we associate with flux from the super-Eddington accretion disk and the dense part of its wind. (2) H-alpha moving components which are formed far from the binary orbital plane in the relativistic jets. (3) H-alpha and He I "stationary" emission lines which we suggest are formed in the disk wind in a volume larger than the dimensions of the binary. (4) A weak "stationary" emission feature we identify as a C II 7231,7236 blend that attains maximum radial velocity at the orbital quadrature of disk recession. (5) Absorption and emission features from outflowing clumps in the disk wind (seen most clearly in an episode of blue-shifted Na I emission). (6) We found no clear evidence of the absorption line spectrum of the optical star, although we point out the presence of He I absorption features (blended with the stationary emission) with the expected radial velocity trend at the orbital and precessional phases when the star might best be seen. (7) A rich interstellar absorption spectrum of diffuse interstellar bands. The results suggest that the binary is embedded in an expanding thick disk (detected in recent radio observations) which is fed by the wind from the super-Eddington accretion disk.