The remarkable X-ray jet in the quasar 4C 20.24

Abstract

The Chandra X-ray telescope has observed a jet in 4C 20.24 (= PKS B1055+201) for which the de-projected length is inferred to be greater than 1 Mpc. The arcsec scale X-ray and 1.46 GHz jets initially follow the direction of the VLBA jet emanating N from the 0.2 mas core, but then curve to the NNW through a total change in angle of about 45 degrees. The 22 arcsec length of the jet gives us one of the best opportunities to study independent spatial elements, in order to infer how the magnetic field and relativistic beaming factor change with distance from the core. We find a constant Doppler factor of about 6, up until the radio structure bends through two 90 degree turns. The remarkable feature of this jet is that we detect extended X-ray emission of about 14 arcsec full width, symmetric about the jet. Furthermore, a similar extended X-ray feature extends to the south, where no radio or X-ray jet is visible, terminating just before the south radio lobe. At the redshift z=1.11 of this quasar, the extended X-ray emission has a luminosity 3E44 ergs per second, comparable to a luminous X-ray cluster. This system gives us a laboratory where we can observe both the jet, and the medium with which it is interacting. Show more