View Full Version : Superluminal jet swing in a Quasar!

2007-Nov-12, 05:12 AM
I've been trying to catch up on my astro-ph e-mails. I noticed this short observational paper, which I thought I'd share since it was so nifty. I didn't see it posted elsewhere on BAUT, but if I've been Toseeked, please link it.

Superluminal non-ballistic jet swing in the quasar NRAO 150 revealed by mm-VLBI (http://arxiv.org/abs/0710.5435), by Agudo et. al (to be published in A&A).

Looking at the paper, it appears that this is by no means the first observation of jet swing. But it's the first example I've seen of this type of motion. Their images of the jet at 43 GHz (7mm) show changes in the flux levels, jet structure and position angle over nearly 10-years, at very high resolution. Of course, we still don't fully understand what is causing these swings, but there are a number of possibilities (including a binary supermassive black hole sysem!).

There was some discussion in an earlier thread (another astro-ph posting regarding Eddington's 1919 eclipse results) about possible VLBI observations of quasar proper motions (http://www.bautforum.com/1068853-post22.html). Well, here's an example of a quasar jet rotating through a large angle over the course of several years! And it looks like the peak flux location shifts around quite a bit.

Also, for those BAUT posters who often say that electricity and magnetism are ignored in mainstream astronomy (you know who you are!):

The results suggest that the magnetic field could play an important role in the dynamics of the jet in NRAO 150, which is supported by the large values of the magnetic field strength obtained from our first estimates.