The Origin of the Nuclear Star-forming Ring in NGC 3182

Abstract

We investigate the stellar and ionized gas kinematics, and stellar populations of NGC 3182 galaxy using integral field spectrograph data from the Calar Alto Legacy Integral Field Area survey. We try to clarify the nature of the ring structure in NGC 3182. We find a negative stellar age gradient out to the ring, while [ α /Fe] considerably enhanced in the ring. The stellar metallicity shows a smooth negative gradient. From the line-ratio diagnostic diagrams, we confirm that NGC 3182 is a Seyfert galaxy from emission-line flux ratio, while the gas in the inner ring is ionized mostly by young stars. However, any obvious feature of outflows is not found in its gas kinematics. In the ring, star formation seems to have recently occurred and the gas metallicity is slightly enhanced compared to the center. From our results, we conclude that star formation has occurred in the circumnuclear region within a short period and this may result from a positive feedback by active galactic nucleus radiation pressure.