Explain the anti-correlation between SS 433 jet speed and polar angle

Establish a physical mechanism that explains the observed negative correlation between variations in the polar angle of the SS 433 jet axis relative to the precession axis and variations in the jet speeds, as inferred from archival optical spectra and radio imaging of SS 433.

Background

SS 433 exhibits precessing relativistic jets whose speeds vary by about 10% around a mean near 0.26c. Analyses of archival optical spectra and radio images have shown that fluctuations in jet speed are anti-correlated with changes in the polar angle of the jet axis relative to the precession axis.

Despite extensive observational characterization—including symmetry between the two jets and nutation—no consensus physical explanation has been established for why faster jet episodes are associated with smaller polar angles. The paper proposes that flaring episodes may affect the slaving of the accretion disk, potentially producing the observed anti-correlation, but the general problem of explaining the correlation is explicitly stated as unresolved.