http://arxiv.org/abs/2301.01610
The Seyfert galaxy NGC 2639 is known to exhibit three episodes of AGN jet/lobe activity. We present here the upgraded Giant Metrewave Radio Telescope (uGMRT) 735 MHz image of NGC 2639 showing a fourth episode as witnessed by the discovery of $\sim9$ kpc radio lobes misaligned with the previously known $\sim1.5$ kpc, $\sim360$ parsec, and $\sim3$ parsec jet features detected through the Karl G. Jansky Very Large Array (VLA) and the Very Long Baseline Array (VLBA), respectively. Using the spectral ageing software BRATS, we derive the ages of the $\sim9$ kpc, $\sim1.5$ kpc, and $\sim360$ parsec episodes to be, respectively, $34^{+4}{-6}$ Myr, $11.8^{+1.7}{-1.4}$ Myr, and $2.8^{+0.7}_{-0.5}$ Myr, and conclude that minor mergers occurred 9-22 Myr apart. NGC 2639 shows a deficit of CO(1-0) molecular gas in its central $\sim6$ kpc region. The GALEX NUV image also shows a clear deficiency of recent star-formation in the same region, while the star formation rate (SFR) surface density in NGC 2639 is lower by a factor of $5-18$ compared to the global Schmidt law of star-forming galaxies. This makes NGC 2639 a rare case of a radio-quiet AGN showing episodic jet activity and possible signatures of negative AGN feedback.
V. Rao, P. Kharb, R. Khatun, et. al.
Thu, 5 Jan 23
14/51
Comments: 9 pages, 6 figures, 3 tables, resubmitted to MNRAS after incorporating the referee’s comments