# Type 2 AGN host galaxies in the Chandra-COSMOS Legacy Survey: No Evidence of AGN-driven Quenching

## TL;DR

This study analyzes the star formation in approximately 2300 X-ray-selected Type 2 AGN host galaxies up to redshift 3, finding no significant evidence that AGN activity influences star formation rates.

## Contribution

It provides a comprehensive multi-wavelength SED analysis of Type 2 AGN hosts, revealing their star formation properties and challenging the idea that AGNs quench or enhance star formation.

## Key findings

- Type 2 AGN hosts have similar SFRs to normal star-forming galaxies.
- No significant evidence of AGN-driven quenching or enhancement.
- Host galaxies are massive, with stellar masses between 10^9 and 10^12 solar masses.

## Abstract

We investigate the star formation properties of a large sample of ~2300 X-ray-selected Type 2 Active Galactic Nuclei (AGNs) host galaxies out to z~3 in the Chandra COSMOS Legacy Survey in order to understand the connection between the star formation and nuclear activity. Making use of the existing multi-wavelength photometric data available in the COSMOS field, we perform a multi-component modeling from far-infrared to near-ultraviolet using a nuclear dust torus model, a stellar population model and a starburst model of the spectral energy distributions (SEDs). Through detailed analysis of SEDs, we derive the stellar masses and the star formation rates (SFRs) of Type 2 AGN host galaxies. The stellar mass of our sample is in the range 9 < log M_{stellar}/M_{\odot} < 12 with uncertainties of ~0.19 dex. We find that Type 2 AGN host galaxies have, on average, similar SFRs compared to the normal star-forming galaxies with similar M_{stellar} and redshift ranges, suggesting no significant evidence for enhancement or quenching of star formation. This could be interpreted in a scenario, where the relative massive galaxies have already experienced substantial growth at higher redshift (z>3), and grow slowly through secular fueling processes hosting moderate-luminosity AGNs.