source comment

Comment on J0457-2324

The source exhibits a mas-scale structure which, according to the USNO multi-epoch monitoring at 2.3 and 8.4 GHz over the period from 1994 July through 1998 April, undergoes considerable changes in the brightness distribution and positions of the major structural features. Our image is qualitatively consistent with the structural pattern of the source. Notably, the ~4 mas SW extension visible in our image is aligned with the 2.3 GHz extension detected at several epochs by the USNO monitoring. The single epoch 15 GHz observation by the USNO group indicates a secondary structure at a distance of ~1 mas towards the SE which is consistent with the model fitting of our data. We note a difference of ~90° in position angles of secondary components in our image and the 5 GHz VLBI image by Shen et al. (1998). Albeit relatively large, this difference could be attributed to the structural variability in the source (the images obtained are separated by 3 years).

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Last modified: 16 Oct 2000