Quasar 3C 454
Movie (0.9 MB, AVI) of the evolution of the parsec-scale
jet of the quasar 3C 454.3. 1 mas = 7.5 parsecs for a Hubble constant of 65
km/s/Mpc. The red contours show total intensity (starting at 64% of the peak
and decreasing by factors of 2), while the colored image corresponds to linearly
polarized intensity. The white sticks show the direction of the electric vector;
the magnetic field is perpendicular to the electric vector except perhaps in
the most compact components, which might be opaque. The lavender vector on the
right shows the 230 GHz polarization of the entire object as measured by the
James Clerk Maxwell Telescope. The inset shows the brightness (flux density)
as measured by the JCMT, with the red arrow showing the current date of the
animation and green arrows showing epochs of actual observations. The movie
is made by linear interpolation of the data. The jet is quite broad, apparently
because the direction of ejection of moving components is not constant. There
is an unresolved stationary feature on the left (eastern) end, customarily called
the "core" that was strangely absent in 1995. There is a second, larger stationary
component about 0.6 mas west of the core. During the movie, a bright spot (elegantly
termed a "blob" by experts) moves through and past this stationary feature,
while a new blob emerges from the core. The blobs travel down the jet at an
apparent speed of 14c. The core seems to be polarized only when it is "giving
birth" to a new blob. The blobs and the stationary component 0.6 mas from the
core usually have magnetic fields that lie at 90 degrees to the jet direction,
as expected for plane-wave shocks. This movie was made by Svetlana Jorstad from
data analyzed by her and Alan Marscher, in collaboration with T. Cawthorne,
A. Stirling, M. Lister, W. Gear, J. Stevens, D. Gabuzda, E.I. Robson, J.R. Forster,
and P. Smith.