Deceleration from Entrainment in the jet of the quasar 1136-135?
  Modeling the multiwavelength emission of successive regions in the jet of the quasar PKS 1136-135 we find indication that the jet suffers deceleration near its end on a (deprojected) scale of ~400 kpc. Adopting a continuous flow approximation we discuss the possibility that the inferred deceleration from a Lorentz factor Gamma=6.5 to Gamma=2.5 is induced by entrainment of external gas. Some consequences of this scenario are discussed. 
F. Tavecchio, L. Maraschi, R.M. Sambruna, M. Gliozzi, C.C. Cheung, J.   F. C. Wardle, C. M. Urry