Issue |
A&A
Volume 457, Number 2, October II 2006
|
|
---|---|---|
Page(s) | 393 - 404 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20065284 | |
Published online | 12 September 2006 |
The XMM large scale structure survey: properties and two-point angular correlations of point-like sources
1
Institute of Astronomy, Madingley Road, University of Cambridge, CB3 0HA, UK e-mail: pg@ast.cam.ac.uk
2
European Southern Observatory, Casilla 19001, Santiago, Chile
3
Institut d'Astrophysique et de Géophysique, Université de Liège, Belgium
4
École Normale Supérieure, Paris, France
5
CEA/DSM/DAPNIA, Service d'Astrophysique, Saclay, 91191 Gif-sur-Yvette, France
6
INAF IASF Milano, via Bassini 15, 20133 Milano, Italy
7
Astrophysics group, Blackett Laboratory, Imperial College, London, UK
Received:
27
March
2006
Accepted:
6
July
2006
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.
Key words: X-rays: diffuse background / large-scale structure of Universe / galaxies: Seyfert
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.