Lunch talk on Mar. 25, 2024

The AGN impact over galaxy evolution: a Near-Infrared perspective with the AGNIFS sample

Speaker: Luis Hahn (SHAO)

Venue: SWIFAR Building 2111

Time: 12:30 PM, Monday, Mar. 25, 2024

Abstract: 

One of the biggest discoveries in modern astrophysics, is that galaxies evolve, from active and star-forming galaxies, to quenched and dead ones. However, the physical mechanisms behind this quenching are still a matter of debate. In modern models and simulations of galaxy evolution, the star  formation  of massive galaxies is regulated by active galactic nuclei (AGN) feedback processes. However, the physics and the extension of such effects on the evolution of galaxies is still unclear. In order to shed some light in the AGN effects over this scenario, we have analysed in the past 10 years the gas and stellar content of the inner 3x3 arcseconds of a large sample composed of 36 Seyfert galaxies. This analysis was performed using Near-Infrared Integral Field Spectroscopy, with a spatial resolution of up to 0.1 arcseconds, achieved through adaptive optics. A few important results that we obtained include: (i) the X-ray luminosity correlates with the kinematical disturbances in discs; (ii) ionized gas is more concentrated in the center, whereas molecular gas is mostly extended, and associated with the disk; (iii) also, the kinematics of the molecular gas is mostly associated with rotation, while ionized gas is a very good tracer for outflows. In some rare cases, however, the molecular gas can trace inflows; (iv) most galaxies show disks dominated by young and intermediate-age stellar populations, which are triggered by the same gas feeding the AGN. These results shed some light on the intricate connection between stellar evolution and nuclear activity. First, the inflowing gas triggers a starburst. Then, it ignites the AGN, which in turn heats and swipes the remaining gas, thus quenching the ongoing star-formation processes.