Structure and Magnetic Fields in the Precessing Jet System SS 433. II. Intrinsic Brightness of the Jets

Deep Very Large Array imaging of the binary X-ray source SS 433, also classified as a microquasar, has been used to study the intrinsic brightness distribution and evolution of its radio jets. The intrinsic brightness of the jets as a function of age at emission of the jet material {tau} is recovered by removal of the Doppler boosting and projection effects. We find that, intrinsically, the two jets are remarkably similar when compared for equal {tau}, and that they are best described by Doppler boosting of the form D {sup 2+{alpha}}, as expected for continuous jets. The intrinsic brightnesses of the jets as functions of age behave in complex ways. In the age range 60 days < {tau} < 150 days, the jet decays are best represented by exponential functions of {tau}, but linear or power-law functions are not statistically excluded. This is followed by a region out to {tau} {approx_equal} 250 days during which the intrinsic brightness is essentially constant. At later times, the jet decay can be fit roughly as exponential or power-law functions of {tau}.