Open AccessOn possible ‘cosmic ray cocoons’ of relativistic jets
Author(s) -
Ostrowski Michał
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03146.x
Subject(s) - physics , cosmic ray , astrophysics , radius , jet (fluid) , astrophysical jet , ultra high energy cosmic ray , acceleration , particle acceleration , radiative transfer , cosmic cancer database , astronomy , active galactic nucleus , classical mechanics , galaxy , mechanics , optics , computer security , computer science
We consider effects on an (ultra)relativistic jet and its ambient medium caused by high‐energy cosmic rays accelerated at the jet side boundary. As illustrated by simple models, during the acceleration process a flat cosmic ray distribution can be created, with gyro‐radii for the highest particle energies reaching scales comparable to the jet radius or energy density comparable to the pressure of the ambient medium. In the case of efficient radiative losses, a high‐energy bump in the spectrum can dominate the cosmic ray pressure. In extreme cases, the cosmic rays are able to push the ambient medium off, providing a ‘cosmic ray cocoon’ separating the jet from the surrounding medium. The considered cosmic rays provide an additional jet braking force and lead to a number of consequences for the jet structure and its radiative output. In particular, the dynamic and acceleration time‐scales involved are in the range observed in variable active galactic nuclei.