# Do AGN outflows quench or enhance star formation?

## TL;DR

This study uses idealised simulations to explore how AGN outflows influence star formation, revealing a complex interplay where outflows can both suppress and trigger star formation depending on luminosity and gas shielding.

## Contribution

The paper introduces a set of idealised simulations examining the dual role of AGN outflows in either quenching or enhancing star formation based on outflow luminosity and gas shielding effects.

## Key findings

- AGN outflows of sufficient luminosity suppress gas fragmentation during activity.
- Gas compression after AGN switches off triggers a burst of star formation.
- A critical AGN luminosity maximizes gas fragmentation rates.

## Abstract

AGN outflows can remove large quantities of gas from their host galaxy spheroids, potentially shutting off star formation. On the other hand, they can compress this gas, potentially enhancing or triggering star formation, at least for short periods. We present a set of idealised simulations of AGN outflows affecting turbulent gas spheres, and investigate the effect of the outflow and the AGN radiation field upon gas fragmentation. We show that AGN outflows of sufficient luminosity shut off fragmentation while the nucleus is active, but gas compression results in a burst of fragmentation after the AGN switches off. Self-shielding of gas against the AGN radiation field allows some fragmentation to occur during outbursts, but too much shielding results in a lower overall fragmentation rate. For our idealised simulation setup, there is a critical AGN luminosity which results in the highest fragmentation rate, with outflows being too efficient at removing gas when $L > L_{\rm crit}$ and not efficient enough to compress the gas to high densities otherwise. These results, although preliminary, suggest that the interaction between AGN and star formation in their host galaxies is particularly complex and requires careful study in order to interpret observations correctly.