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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

X-ray extragalactic surveys are ideal laboratories for the study of theevolution and clustering of active galactic nuclei (AGN). The XXL Survey spanstwo fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton,occupying the parameter space between deep surveys and very wide area surveys;at the same time it benefits from a wealth of ancillary data. This paper marksthe first release of the XXL point source catalogue selected in the 2-10 keVenergy band with limiting flux$F_{2-10keV}=4.8\cdot10^{-14}\rm{erg\,s^{-1}\,cm^{-2}}$. We use both public andproprietary data sets to identify the counterparts of the X-ray point-likesources and improved upon the photometric redshift determination for AGN byapplying a Random Forest classification trained to identify for each object theoptimal photometric redshift model library. We also assign a probability toeach source to be a star or an outlier. We model with Bayesian analysis theX-ray spectra assuming a power-law model with the presence of an absorbingmedium. We find an average unabsorbed photon index of $\Gamma=1.85$ and averagehydrogen column density $\log{N_{H}}=21.07 cm^{-2}$. We find no trend of$\Gamma$ or $N_H$ with redshift and a fraction of 26% absorbed sources ($\logN_{H}>22$). We show that the XXL-1000-AGN number counts extended the numbercounts of the COSMOS survey to higher fluxes and are fully consistent with theEuclidean expectation. We constrain the intrinsic luminosity function of AGN inthe 2-10 keV energy band where the unabsorbed X-ray flux is estimated from theX-ray spectral fit up to z=3. Finally, we demonstrate the presence of asupercluster size structure at redshift 0.14, identified by means ofpercolation analysis of the XXL-1000-AGN sample. The XXL survey, reaching amedium flux limit and covering a wide area is a stepping stone between currentdeep fields and planned wide area surveys.

The XXL Survey: VI. The 1000 brightest X-ray point sources