| 25th of September 2017 |
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| VLBI images of active galactic nuclei |
| (by Müller et al.) |
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TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond
Interferometry) is a multiwavelength project to monitor relativistic
jets in active galactic nuclei (AGN) of the Southern Sky.
In particular, TANAMI is targetting active galaxies which have been
detected at gamma-ray energies by NASA's Fermi satellite.
The team's second paper, containing high angular resolution images of the centres of
39 active galaxies, has recently been accepted for publication.
TANAMI Very Long Baseline Interferometry (VLBI) observations at 8.4 GHz are made with
Southern-Hemisphere radio telescopes located in Australia, Antarctica,
Chile, New Zealand, and South Africa.
The image above is of the relatively nearby galaxy PKS 1343-601, also
known as Centaurus B. The brightest part of the radio image is at
top left, and this the core of the galaxy, where the super-massive
black hole (that powers the radio jet) resides. The jet appears in the
image to be one-sided, however it is believed that it is intrinsically
two-sided, with the visible jet directed close to our line of sight
and the relativistic speed of the jet resulting in it being strongly
boosted. In contrast, the other side is directed in the opposite
direction and is strongly boosted in that direction, rendering it
invisible at the sensitivity limit of this image.
PKS 1343-601 is an example of a jet which contains some hotspots
but which is otherwise continuous over its length, in contrast
to the jets of other sources, as will be illustrated over the next few days.
More details are given in the pre-print of the paper by Müller et al. |