Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-09-28
The Astrophysical Journal 706 (2009) 1253-1268
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
17 pages, 11 figures, 1 table, accepted by the Astrophysical Journal
Scientific paper
10.1088/0004-637X/706/2/1253
We discuss acceleration measurements for a large sample of extragalactic radio jets from the MOJAVE program which studies the parsec-scale jet structure and kinematics of a complete, flux-density-limited sample of Active Galactic Nuclei (AGN). Accelerations are measured from the apparent motion of individual jet features or "components" which may represent patterns in the jet flow. We find that significant accelerations are common both parallel and perpendicular to the observed component velocities. Parallel accelerations, representing changes in apparent speed, are generally larger than perpendicular acceleration that represent changes in apparent direction. The trend for larger parallel accelerations indicates that a significant fraction of these changes in apparent speed are due to changes in intrinsic speed of the component rather than changes in direction to the line of sight. We find an overall tendency for components with increasing apparent speed to be closer to the base of their jets than components with decreasing apparent speed. This suggests a link between the observed pattern motions and the underlying flow which, in some cases, may increase in speed close to the base and decrease in speed further out; however, common hydro-dynamical processes for propagating shocks may also play a role. About half of the components show "non-radial" motion, or a misalignment between the component's structural position angle and its velocity direction, and these misalignments generally better align the component motion with the downstream emission. Perpendicular accelerations are closely linked with non-radial motion. When observed together, perpendicular accelerations are usually in the correct direction to have caused the observed misalignment.
Homan Daniel C.
Kadler Matthias
Kellermann Kenneth I.
Kovalev Yu. Yu.
Lister Matthew L.
No associations
LandOfFree
MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. VII. Blazar Jet Acceleration does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. VII. Blazar Jet Acceleration, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. VII. Blazar Jet Acceleration will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-235163