On the arcmin structure of the X-ray Universe

TL;DR

This study analyzes the clustering of X-ray sources from a large dataset, revealing significant AGN clustering at redshift ~1 and providing insights into their dark matter halo environments and lifetimes.

Contribution

It presents the largest and most accurate clustering analysis of X-ray sources, offering new measurements of AGN spatial distribution and dark matter halo associations.

Findings

Significant clustering detected in soft and hard X-ray bands.

AGN at z~1 reside in dark matter halos of ~10^12.6 M_sun.

AGN activity lasts approximately 300-500 million years.

Abstract

We present the angular correlation function of the X-ray population of 1063 XMM-Newton observations at high Galactic latitudes, comprising up to ~30000 sources over a sky area of ~125 sq. degrees in the energy bands: soft (0.5-2 keV) and hard (2-10 keV). This is the largest sample of serendipitous X-ray sources ever used for clustering analysis purposes to date and the results have been determined with unprecedented accuracy. We detect significant clustering signals in the soft and hard bands (~10 sigma and ~5 sigma, respectively). We deproject the angular correlation function via Limber's equation and calculate the typical spatial lengths. We infer that AGN at redshifts ~1 are embedded in dark matter halos with typical masses of log M ~ 12.6/h Msol and lifetimes in the range ~3-5 x 10^8 years, which indicates that AGN activity is a transient phase in the life of galaxies.