On the jet speeds of classical double radio sources
نویسندگان
چکیده
A simple integral relation is obtained for the distribution functions of jet speeds and jet-counterjet flux asymmetries of classical double radio sources. Analytic expressions relating the mean jet speed and the mean jet flux asymmetry, and their variances are derived. The results are considered in the light of orientation-based unified schemes, and an analytical equation for the critical angle separating quasars and radio galaxies is derived. The mean jet speeds of classical double radio sources are estimated using the asymmetry of jet-counterjet flux densities taken from the 3CRR and B2 samples. For FRI radio sources the mean jet speed is ∼ (0.54± 0.03)c, while for FRII low-redshift radio galaxies and intermediate redshift quasars the values found are ∼ (0.4 ± 0.06)c and ∼ 0.6c respectively.
منابع مشابه
Multiwavelength study of Cygnus A I. Precession and slow jet speeds from radio observations
We study the jet and counterjet of the powerful classical double FRII radio galaxy Cygnus A as seen in the 5, 8 and 15-GHz radio bands using the highest spatial resolution and signal-tonoise archival data available. We demonstrate that the trace of the radio knots that delineate the jet and counterjet deviates from a straight line and that the inner parts can be satisfactorily fitted with the p...
متن کاملAn asymmetric relativistic model for classical double radio sources
There is substantial observational evidence against the symmetric relativistic model of FRII radio sources. An asymmetric relativistic model is proposed which takes account of both relativistic effects and intrinsic/environmental asymmetries to explain the structural asymmetries of their radio lobes. A key parameter of the model is the jet-side of the double sources, which is estimated for 80% ...
متن کاملExtended radio emission in Mojave blazars: Challenges to unification
We present the results of a study on the kiloparsec-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud active galactic nuclei. New 1.4 GHz Very Large Array (VLA) radio images of six quasars and previously unpublished images of 21 blazars are presented, along with an analysis of the high-resolution (VLA A-array) 1.4 GHz emission for the entire samp...
متن کاملJet deflections in radio galaxies
Convincing evidence for the interaction between jets and their environments has been found inmany extragalactic radio sources. In some radio galaxies these interactions appear to cause the jet to be deflected, not completely stopped or disrupted. This paper presents a simple model which accounts for jet deflections with oblique shocks in a relativistic flow. Using the model in conjunction with ...
متن کاملBayesian inference of jet bulk-flow speeds in FRII radio sources
Radio jet and core data for a complete sample of 98 FRII sources with z < 1 are analysed with a Markov-Chain Monte Carlo (MCMC) model fitting method to obtain constraints on bulk-flow speeds in the beam. The Bayesian parameter-inference method is described and demonstrated to be capable of providing meaningful constraints on the Lorentz factor at both kiloparsec and parsec scales. For both jets...
متن کامل