Traces of co-evolution in high z X-ray selected and submm-luminous QSOs

TL;DR

This study analyzes the spectral energy distributions of five high-redshift, X-ray selected, submillimeter-bright QSOs to explore their star formation and black hole growth, revealing high SFRs, massive hosts, and potential links between AGN activity and star formation.

Contribution

It provides a detailed SED analysis of high-z QSOs with new Herschel data, estimating black hole masses, luminosities, and SFRs, and suggests a possible correlation between ionized gas column density and star formation rate.

Findings

High SFRs of 400-1400 solar masses per year.

Black hole masses between 10^9 and 10^10 solar masses.

Evidence of a correlation between ionized gas column density and SFR.

Abstract

We present a detailed study of a X -ray selected sample of 5 submillimeter bright QSOs at $z\sim2$, where the highest rates of star formation (SF) and further growth of black holes (BH) occur. Therefore, this sample is a great laboratory to investigate the co-evolution of star formation and AGN. We present here the analysis of the spectral energy distributions (SED) of the 5 QSOS, including new data from Herschel PACS and SPIRE. Both AGN components (direct and reprocessed) and like Star Formation (SF) are needed to model its SED. From the SED and their UV-optical spectra we have estimated the mass of the black hole ($M_{BH} = 10^9 - 10^{10} M_{SUN}$) and bolometric luminosities of AGN ($L_{BOL} = (0.8-20) \times 10^{13} L_{SUN}$). These objects show very high luminosities in the far infrared range (at the H/ULIRG levels) and very high rates of SF (SFR = 400-1400 $M_{SUN}$/y). Known their current SFR and their BH masses, we deduce that their host galaxies must be already very massive, or would not have time to get to the local relation between BH mass and bulge. Finally, we found evidence of a possible correlation between the column density of ionized gas detected in X-rays ($NH_{ion}$) and SFR, which would provide a link between AGN and SF processes.