|15th of May 2015|
|VLBI observations of the nearby giga-hertz peaked spectrum source PKS 2254-367|
|by Phil Edwards (CASS)|
|PKS 2254-367 was identified as a member of
the class of GHz-peaked spectrum (GPS) galaxy in earlier ATCA observations,
and is of particular interest as it is one of the closest GPS galaxies known.
At a distance of "only" 20 mega-parsecs, we are able to study the galaxy at
higher linear resolution, i.e., in finer detail, than more distant sources.
We used the Very Long Baseline Array to image the parsec-scale structure of
the galaxy at four frequencies. These images reveal the galaxy can be further
categorised as a compact symmetric object, with a bright radio core (which
we believe is co-located with the supermassive black hole at the heart of the
galaxy) and fainter, symmetric jets of radio-emitting plasma on either side.
The many similarities between PKS 2254-367 and another nearby GPS galaxy,
NGC 1052, lead us to speculate that a sub-class of GPS radio sources, with
low luminosity and with jet-dominated morphologies, exists and would be
largely absent from existing radio source surveys. |
Reference: Tingay & Edwards 2015, MNRAS, 448, 252