Bibcode
Scarpa, R.; Urry, C. M.
Referencia bibliográfica
American Astronomical Society, 194th AAS Meeting, #20.05; Bulletin of the American Astronomical Society, Vol. 31, p.857
Advertised on:
5
1999
Número de citas
0
Número de citas referidas
0
Descripción
We discuss the energy budget of AGN jets, based on available data for
all 14 having detected optical synchrotron emission. Assuming
equipartition between magnetic field and particle energy, these jets
transport enough kinetic energy to power a typical extended radio lobe
only if the bulk motion of the jet plasma is at least moderately
relativistic (v>0.75c). This suggests that, like the M87 jet, all
optical jets could be be relativistic on kiloparsec scales, generalizing
what has already been found for parsec scales based on radio data alone.
In several cases, the jets are longer, by up to two orders of magnitude,
than implied by electron lifetimes, unless there is particle
reacceleration along the jet. Alternatively, if the magnetic field
strength is an order of magnitude below the equipartition value, and the
jets are still moderately relativistic, their lengths are commensurate
with the intrinsic radiative lifetimes of the electrons. In this case,
relativistic particles carrying most of the energy, roughly 10(3-10^4)
times the energy density of the magnetic field. These optical data,
though sparse, greatly improve constraints on the intrinsic physical
conditions in jets.