AGN feedback and star formation in the peculiar galaxy NGC 232: insights from VLT-MUSE observations

Costa-Souza, José Henrique; Riffel, Rogemar A.; Dors, Oli L.; Riffel, Rogério; da Rocha-Poppe, Paulo C.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society

Advertised on:
1
2024
Number of authors
5
IAC number of authors
1
Citations
1
Refereed citations
0
Description
We use VLT-MUSE integral field unit data to study the ionized gas physical properties and kinematics as well as the stellar populations of the Seyfert 2 galaxy NGC 232 as an opportunity to understand the role of AGN feedback on star formation. The data cover a field of view of 60 × 60 arcsec2 at a spatial resolution of ~850 pc. The emission-line profiles have been fitted with two Gaussian components, one associated to the emission of the gas in the disc and the other due to a bi-conical outflow. The spectral synthesis suggests a predominantly old stellar population with ages exceeding 2 Gyr, with the largest contributions seen at the nucleus and decreasing outwards. Meanwhile, the young and intermediate age stellar populations exhibit a positive gradient with increasing radius and a circum-nuclear star-forming ring with radius of ~0.5 kpc traced by stars younger than 20 Myr, is observed. This, along with the fact that AGN and SF dominated regions present similar gaseous oxygen abundances, suggests a shared reservoir feeding both star formation and the AGN. We have estimated a maximum outflow rate in ionized gas of ~1.26 M⊙ yr-1 observed at a distance of ~560 pc from the nucleus. The corresponding maximum kinetic power of the outflow is ~3.4 × 1041 erg s-1. This released energy could be sufficient to suppress star formation within the ionization cone, as evidenced by the lower star formation rates observed in this region.