THE OPTICAL JETS OF SS-433 - PHYSICAL PARAMETERS

The Balmer decrements of the emission Lines of the SS 433 jets are der ived using data from the Special Astrophysical Observatory 6-m telesco pe. The Balmer decrements for the two jets are very similar. Like the intensities of the moving lines, they vary with precessional phase and are significantly different at the phases of minimum and maximum movi ng line intensity. Their mean values-H-alpha/H-beta 1.3 and H-gamma/H- beta = 0.8-suggest the gas density is roughly 10(13) cm(-3). The physi cal parameters of the gas and the gaseous clouds in the jets are deriv ed. The kinetic luminosity of the jets is of the order of 10(39) erg/s , and the clouds are optically thick in the H-alpha line and have size s of about 10(8) cm. The clouds may group in clusters with size 10(12) cm. The behavior of the Balmer decrements and moving Line intensities provides evidence that the optical depth of the emitting gas layer to ward the observer decreases near precessional phase 0.8. This may be c aused by a nonspherical shape of the gas clouds or brightening of the gas by shock waves. A determining factor in the cloud dynamics and the formation of the jet emission is the interaction of the jets with the gas from a slow accretion disk wind, This interaction occurs to a dis tance from the source of about 3 x 10(15) cm, where the jets sweep out the impinging gas. Further, an expansion zone forms in the jets, to a distance of approximately 4 x 10(15) cm. In this region, the jets pro pagate through a gas-free space, and the gas clouds rapidly expand, fi lling the entire jet volume. This gives rise to a zone of synchrotron emission brightening at a distance of about 4 x 10(15) cm.