arXiv:astro-ph/0209234astro-ph
The Central Parsecs of the Bright Quasar PKS 1921 - 293
Early discovery. Linked by one identifiable commenter. This paper is outside the main ranking; a mention is not an endorsement.
Abstract
We report on a VLBA imaging study of the nearby bright southern blazar PKS 1921 - 293 (OV - 236). High resolution VLBA observations, made at four frequencies (5, 12, 15, and 43 GHz) over the period 1994 - 2000, have revealed a strongly curved jet extending out to about 50 parsecs from the presumed central engine. Two epoch VLBA observations, each simultaneously carried out at both 5 and 43 GHz, show a large position angle difference of 51 - 67 degrees between the jet emission at 5 and 43 GHz. Although the core of PKS 1921 - 293 has one of the highest brightness temperatures measured in any compact radio source, unlike other bright blazars it is not a source of gamma-ray emission. However, there is evidence in these images for superluminal motion within the central region (a few parsecs from the core) and within the north-east diffuse emission region. In all six-epoch 43 GHz images, two equally compact bright components within the central parsec are seen.
They've used the blazar J1924-2914 to calibrate[1] for Sagittarius A*. From the paper[2]: It can be seen from Table 1 and Figure 4 that the inner jet structure determined by 1.3 mm VLBI agrees well with the reported inner jet orientation at lower frequencies (e.g., Shen et al.…
magicalhippoView on HNParent context