Multi-wavelength Properties of Type 1 and Type 2 AGN Host Galaxies in the Chandra-COSMOS Legacy Survey

Suh, Hyewon; Civano, Francesca; Hasinger, Günther; Lusso, Elisabeta; Marchesi, Stefano; Schulze, Andreas; Onodera, Masato; Rosario, David J.; Sanders, David B.

Abstract

We investigate the multi-wavelength properties of host galaxies of 3701 X-ray-selected active galactic nuclei (AGNs) out to z ~ 5 in the Chandra-COSMOS Legacy Survey. Thanks to the extensive multi-wavelength photometry available in the COSMOS field, we derive AGN luminosities, host stellar masses, and star formation rates (SFRs) via a multi-component SED fitting technique. Type 1 and Type 2 AGNs follow the same intrinsic L 2–10 keV–L 6 μm relation, suggesting that mid-infrared emission is a reasonably good measure of the AGN accretion power regardless of obscuration. We find that there is a strong increase in Type 1 AGN fraction toward higher AGN luminosity, possibly due to the fact that Type 1 AGNs tend to be hosted by more massive galaxies. The AGN luminosity and SFR are consistent with an increase toward high stellar mass, while the M stellar dependence is weaker toward the high-mass end, which could be interpreted as a consequence of quenching both star formation and AGN activity in massive galaxies. AGN host galaxies tend to have SFRs that are consistent with normal star-forming galaxies, independent of AGN luminosities. We confirm that black hole accretion rate and SFR are correlated up to z ~ 5, when forming stars. The majority (~73%) of our AGN sample are faint in the far-infrared, implying that the moderate-luminosity AGNs seem to be still active after the star formation is suppressed. It is not certain whether AGN activity plays a role in quenching the star formation. We conclude that both AGN activity and star formation might be more fundamentally related to host stellar mass.

Citation

Suh, H., Civano, F., Hasinger, G., Lusso, E., Marchesi, S., Schulze, A., Onodera, M., Rosario, D. J., & Sanders, D. B. (2019). Multi-wavelength Properties of Type 1 and Type 2 AGN Host Galaxies in the Chandra-COSMOS Legacy Survey. Astrophysical Journal, 872(2), Article 168. https://doi.org/10.3847/1538-4357/ab01fb

• Journal Article Type: Article
• Acceptance Date: Jan 25, 2019
• Online Publication Date: Feb 20, 2019
• Publication Date: Feb 20, 2019
• Deposit Date: Mar 7, 2019
• Publicly Available Date: Mar 7, 2019
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 872
• Issue: 2
• Article Number: 168
• DOI: https://doi.org/10.3847/1538-4357/ab01fb
• Public URL: https://durham-repository.worktribe.com/output/1306765