Demography of High-Redshift AGN

الملخص EN

High-redshift AGN holds the key to understanding early structure formation and to probe the Universe during its infancy.

We review the latest searches for high-z AGN in the deepest X-ray field so far, the Chandra Deep Field South (CDFS) 4 Msecond exposure.

We do not confirm the positive detection of a signal in the stacked Chandra images at the position of z~6 galaxies recently reported by Treister and collaborators (2011).

We present z>3 X-ray sources number counts in the 0.5–2 keV band, obtained joining CDFS faint detections (see Fiore et al.

(2011)), with Chandra-COSMOS and XMM-COSMOS detections.

We use these number counts to make predictions for surveys with three mission concepts: Athena, WFXT, and a Super-Chandra.