We present arguments indicating that radio jets are heavy (i.e. mainly composed of an electron-proton plasma), and that the non-thermal emitting particle distribution has a low-energy cut-off at about 50 MeV. The arguments are based on the comparison of physical properties of parsec-scale radio jets with values estimated on widely different scales, ranging from the central source supplying the jet to extended kpc-Mpc radio lobes. In particular, we use published VLBI size measures and spectral information on a large sample of sources and, applying the standard synchrotron self-Compton emission model, we estimate the bulk kinetic energy and the number flux of emitting particles in parsec-scale jets. The comparison of the former with the kinetic luminosity on extended scales and with the radiative luminosity supports the picture of stable jets efficiently supplying kinetic power to the extended structures. The requirement that, at the same time, the particle flux is supplied from the central, compact source allows us to constrain the matter content of jets and the energy distribution of the emitting particles.
|Titolo:||The kinetic power and luminosity of parsec-scale radio jets; an argument for heavy jets|
|Autori:||Celotti A; Fabian A.C.|
|Data di pubblicazione:||1993|
|Appare nelle tipologie:||1.1 Journal article|