Submm-bright QSOs at z~2: signposts of co-evolution at high z

TL;DR

This study analyzes five z~2 QSOs that are both X-ray and submm luminous, revealing they are undergoing intense star formation and black hole growth, providing insights into galaxy and AGN co-evolution at high redshift.

Contribution

It presents a combined analysis of AGN and star formation contributions in z~2 QSOs, confirming intense star formation and estimating their covering factors, advancing understanding of galaxy-AGN co-evolution.

Findings

Star formation rates between 500-2000 solar masses per year.

Covering factors estimated between 30% and 90%.

All three components (disk, torus, star formation) are necessary to fit the SEDs.

Abstract

We have assembled a sample of 5 X-ray and submm-luminous z~2 QSOs which are therefore both growing their central black holes through accretion and forming stars copiously at a critical epoch. Hence, they are good laboratories to investigate the co-evolution of star formation and AGN. We have performed a preliminary analysis of the AGN and SF contributions to their UV-to-FIR SEDs, fitting them with simple direct (disk), reprocessed (torus) and star formation components. All three are required by the data and hence we confirm that these objects are undergoing strong star formation in their host galaxies at rates 500-2000 Msun/y. Estimates of their covering factors are between about 30 and 90%. In the future, we will assess the dependence of these results on the particular models used for the components and relate their observed properties to the intrinsice of the central engine and the SF material, as well as their relevance for AGN-galaxy coevolution.