The optical jets of SS433: Anisotropy of the emission

Spectral data on hydrogen emission lines from the jets of SS433 obtained on the SAO 6-m telescope are presented, together with the results of multicolor photometry of this object. The dependences of the fluxes in the U, B, and R filters on the V flux are obtained. The dependence of the intensity of the moving lines in a co-moving coordinate system on the precession phase is found using these data and data from the literature. The maximum jet emission occurs at a phase of about 0.8. The observed precession intensity curves can be understood if the directional pattern for the jet emission has two maxima placed approximately symmetrically with respect to the center, with the lead maximum having a small angle to the jet velocity vector, towards the direction of the precessional motion. In an empirical model of the directional pattern, the leading part of the gas cloud surface in the jets is a factor of 1.5-2.0 brighter than the trailing part. Two models in which this anisotropic jet emission forms in (1) individually optically thick clouds and (2) the opaque jet as a whole (or in clusters of clouds) are discussed. These models assume that the origin for the emission anisotropy is a non-spherical shape for the emission source or the brightening of gas in shock waves propagating in the jet. It is proposed that the anisotropy of the emission of SS433 is caused by the dynamic interaction of the precessing jets with the slow wind from an accretion disk.