@proceedings{13023, author = {Mitchell Begelman}, editor = {Hermann-Josef Röser and Klaus Meisenheimer}, title = {Velocity and confinement of large-scale jets}, abstract = {

I consider several issues connected with the velocities and confinement properties of kpc-scale jets in FRII sources. There is considerable evidence that large-scale jets are at least mildly relativistic. I discuss whether the Doppler-beaming interpretation of one-sidedness can be reconciled with Barthel s unified scheme, and consider modifications to the Doppler beaming formula due to the directionality of the magnetic field. The synchrotron-emitting regions of many FRII jets appear to be overpressured with respect to their surroundings, and yet seem to be effectively confined. I consider several possible confinement mechanisms, and discuss the implications of a small volume filling factor in the synchrotron emissivity. Finally, I argue that most lobe asymmetry could be due to environmental effects, and show that even a small asymmetry in the ambient intergalactic medium can lead to a large asymmetry in lobe/core separation.

}, year = {1993}, volume = {421}, pages = {145-156}, month = {1993-01}, publisher = {Springer Berlin Heidelberg}, address = {Berlin, Heidelberg}, isbn = {978-3-540-47925-3}, doi = {10.1007/3-540-57164-7_91}, }