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The radio jets in B2 0755+379 |
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| Authors: | M Bondi P Parma H de Ruiter R Fanti R A Laing E B Fomalont |
| Institution: | Istituto di Radioastronomia, Via Gobetti 101, I-40129, Bologna, Italy; Osservatorio Astronomico, Bologna, Italy; Dipartimento di Fisica, Universitàdi Bologna, Bologna, Italy; University of Oxford, Department of Astrophysics, Nuclear and Astrophysics Laboratory, Keble Road, Oxford OX1 3RH; Space Science and Technology Department, CLRC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX; National Radio Astronomy Observatory, Charlottesville, VA22903, USA |
| Abstract: | We present and discuss observations of the radio galaxy 0755+379 made with the VLA at 1.4 and 5.0 GHz and with MERLIN at 1.7 GHz. These data allow us to image the radio jets over two orders of magnitude in linear size and to investigate the hypothesis that jets in low-luminosity radio galaxies start with velocities close to c and then slow down to subrelativistic speeds. We apply a model for an adiabatically expanding relativistic jet to the observed surface brightness and derive velocity profiles along the jet for various assumed starting conditions. We show that these profiles are consistent with the observed jet/counter-jet brightness ratios provided that the angle to the line of sight θ ?27°. The inferred velocity at a distance of 0.5 kpc from the nucleus is ?0.9 c . Finally, we show that the predicted velocity at 10 kpc from the nucleus is consistent with that obtained independently from energy-balance arguments. |
| Keywords: | galaxies: active galaxies: individual: 0755+379 galaxies: jets radio continuum: galaxies |