Opacity in parsec-scale jets of active galactic nuclei: VLBA study from 1.4 to 15 GHz

Kovalev, Y. Y.; Pushkarev, A. B.; Lobanov, A. P.; Sokolovsky, K. V.

Opacity in parsec-scale jets of active galactic nuclei: VLBA study from 1.4 to 15 GHz

Authors

Description

In extragalactic jets, the apparent position of the bright/narrow end (the core) depends on the observing frequency, owing to synchrotron self-absorption and external absorption. The effect must be taken into account in order to achieve unbiased results from multi-frequency VLBI data on AGN jets. Multi-frequency core shift measurements supplemented by other data enable estimating the absolute geometry and a number of fundamental physical properties of the jets and their environment. We have previously measured the shift between 13 and 3.6 cm in a sample of 29 AGNs to range between 0 and 1.4 mas. In these proceedings, we present and discuss first results of our follow-up study using VLBA between 1.4 and 15.4 GHz.
6 pages, 3 figures, to appear in Proceedings of Science, Proceedings of The 9th European VLBI Network Symposium on The role of VLBI in the Golden Age for Radio Astronomy and EVN Users Meeting