Measuring the jet power of flat spectrum radio quasars
  We use frequency-dependent position shifts of flat spectrum radio cores to estimate the kinetic power of AGN jets. We find a correlation between the derived jet powers and AGN narrow-line luminosity, consistent with the well-known relation for radio galaxies and steep spectrum quasars. This technique can be applied to intrinsically weak jets even at high redshift. 
Stanislav Shabala, Jesse Santoso, Leith Godfrey
astro-ph.CO