English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The XLF of AGN offers a robust tool to study the evolution and the growth ofSMBHs over cosmic time. Owing to the limited area probed by X-ray surveys,optical surveys are routinely used to probe the accretion in the high redshiftUniverse $z\geq 3$. However, optical surveys may be incomplete because they arestrongly affected by dust redenning. In this work, we derive the XLF and itsevolution at high redshifts using a large sample of AGNs selected in differentfields with various areas and depths covering a wide range of luminosities.Additionally, we put the tightest yet constraints on the absorption function inthis redshift regime. In particular, we use more than 600 soft X-ray selectedhigh-z sources in the Chandra Deep fields, the Chandra COSMOS Legacy survey andthe XMM-XXL northern field. We derive the X-ray spectral properties for allsources via spectral fitting, using a consistent technique and model. Formodeling the parametric form of the XLF and the absorption function, we use aBayesian methodology allowing us to correctly propagate the uncertainties forthe observed X-ray properties of our sources and also the absorption effects.The evolution of XLF is in agreement with a pure density evolution modelsimilar to what is witnessed at optical wavelengths, although a luminositydependent density evolution model cannot be securely ruled out. A largefraction ($60\%)$ of our sources are absorbed by column densities of $\rm N_H\geq 10^{23} cm^{-2} $, while $17$\% of the sources are CTK. Our results favora scenario where both the ISM of the host and the AGN torus contribute to theobscuration. The derived BHAD is in agreement with the simulations, if onetakes into account that the X-ray AGN are hosted by massive galaxies, while itdiffers from the one derived using JWST data. The latter could be due to thedifferences in the AGN and host-galaxy properties.

AGN X-ray luminosity function and absorption function in the Early Universe ($3\leq z \leq 6$)