2006/07/07 by P. Gandhi, O. Garcet, Ludovic Disseau +11 · 2 citations
Mathematics · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Correlation function (quantum field theory) #Detector #Galaxies: Formation, Evolution, Phenomena #Mathematics #Optics #Physics #Point source #Poisson distribution #Quantum mechanics #Sampling (signal processing) #Scale (ratio) #Sky #Statistics #astro-ph
paper · pdf · doi:10.1051/0004-6361:20065284
published as Astron.Astrophys.457:393-404,2006 · A&A in press; High resolution version at http://www-xray.ast.cam.ac.uk/~pg/publications.html
arxiv created 2006/07/07 · openalex publication_date 2006/08/04 · arxiv updated 2014/10/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyze X-ray sources detected over 4.2 pseudo-contiguous sq. deg. in the 0.5–2 keV and 2–10 keV bands down to fluxes of and erg s-1 cm-2 respectively, as part of the XMM-Newton Large Scale Structure Survey. The log N–log S in both bands shows a steep slope at bright fluxes, but agrees well with other determinations below ~ erg s-1 cm-2. The detected sources resolve close to 30 per cent of the X-ray background in the 2–10 keV band. We study the two-point angular clustering of point sources using nearest neighbours and correlation function statistics and find a weak, positive signal for ~1130 sources in the 0.5–2 keV band, but no correlation for ~400 sources in the 2–10 keV band below scales of 100 arcsec. A sub-sample of ~200 faint sources with hard X-ray count ratios, that is likely to be dominated by obscured AGN, does show a positive signal with the data allowing for a large angular correlation length, but only at the ~2 (3)σ level, based on re-sampling (Poisson) statistics. We discuss possible implications and emphasize the importance of wider, complete surveys in order to fully understand the large scale structure of the X-ray sky.