FRAMEx. IV. Mechanical Feedback from the Active Galactic Nucleus in NGC 3079

Abstract

Using the Very Long Baseline Array, we observed the active galactic nucleus (AGN) in NGC 3079 over a span of six months to test for variability in the two main parsec-scale radio components, A and B , which lie on either side of the AGN. We found evidence for positional differences in the positions of A and B over the six months consistent with the apparent motion of these components extrapolated from older archival data, finding that their projected rate of separation, (0.040 ± 0.003) c , has remained constant since ∼2004 when a slowdown concurrent with a dramatic brightening of source A occurred. This behavior is consistent with an interaction of source A with the interstellar medium (ISM), as has previously been suggested in the literature. We calculated the amount of mechanical feedback on the ISM for both the scenario in which A is an expulsion of material from the central engine and the scenario in which A is a shock front produced by a relativistic jet, the latter of which is favored by several lines of evidence we discuss. We find that the cumulative mechanical feedback on the ISM is between 2 × 10 ^44 and 1 × 10 ^48 erg for the expulsion scenario or between 3 × 10 ^50 and 1 × 10 ^52 erg for the jet scenario. Integrated over the volume-complete Fundamental Reference AGN Monitoring Experiment (FRAMEx) sample, our results imply that jet-mode mechanical feedback plays a negligible role in the energetics of AGNs in the local Universe.

Keywords

• Active galactic nuclei
• X-ray active galactic nuclei
• Radio active galactic nuclei
• Radio jets
• Very long baseline interferometry