Gas outflows in Seyfert galaxies: effects of star formation versus AGN feedbacks

TL;DR

This study uses high-resolution hydrodynamical simulations to investigate how star formation and AGN feedback influence gas outflows in Seyfert galaxies, revealing star formation's dominant role at nuclear scales.

Contribution

It provides new insights into the relative impacts of star formation and AGN jets on gas outflows in Seyfert galaxies through detailed simulations.

Findings

Star formation alone can drive outflows within 1 kpc.

AGN jets can accelerate gas clumps but do not cause massive outflows.

Star formation is the primary driver of nuclear outflows.

Abstract

Large scale, weakly collimated outflows are very common in galaxies with large infrared luminosities. In complex systems in particular, where intense star formation (SF) coexists with an active galactic nucleus (AGN), it is not clear yet from observations whether the SF, the AGN, or both are driving these outflows. Accreting supermassive black holes (SMBHs) are expected to influence their host galaxies through kinetic and radiative feedback processes, but in a Seyfert galaxy where the energy emitted in the nuclear region is comparable to that of the body of the galaxy, it is possible that stellar activity is also playing a key role in these processes. In order to achieve a better understanding of the mechanisms driving the gas evolution specially at the nuclear regions of these galaxies, we have performed high-resolution three-dimensional hydrodynamical simulations with radiative cooling considering the feedback from both star formation regions including supernova (type I and II) explosions and an AGN jet emerging from the central region of the active spiral galaxy. We computed the gas mass lost by the system, separating the role of each of these injection energy sources on the galaxy evolution and found that at scales within one kiloparsec an outflow can be generally established considering intense nuclear star formation only. The jet alone is unable to drive a massive gas outflow, although it can sporadically drag and accelerate clumps of the underlying outflow to very high velocities.