The faint X-ray Source Population near 3C 295

Abstract

We present a statistical analysis of the Chandra observation of the source field around the 3C 295 galaxy cluster (z=0.46) aimed at the search for clustering of X-ray sources. We applied three different methods of analysis, all suggesting a strong clustering in the field on scales of a few arcmin. In particular 1) the logN-logS computed separately for the four ACIS-I chips reveals that there is a significant (3.2 sigma in the 0.5-2 keV, 3.3 sigma in the 2-10 keV and 4.0 sigma in the 0.5-10 keV band) excess of sources to the North-North East and a void to the South of the central cluster. 2) the two point, two-dimensional Kolmogorov-Smirnov (KS) test, shows the probability that the sources are uniformly distributed is only a few percent. 3) a strong spatial correlation emerges from the study of the angular correlation function of the field: the angular correlation function (ACF) shows a clear signal on scales of 0.5 - 5 arcmin, correlation angle in the 0.5-7 keV band theta = 8.5^{+6.5}_{-4.5}, 90% confidence limit (assuming a power law ACF with slope gamma=1.8). This correlation angle is 2 times higher than that of a sample of 8 ACIS-I field at the 2.5 sigma confidence level. The above scales translate to 0.2 - 2 Mpc at the cluster redshift, higher than the typical cluster core radius, and more similar to the size of a ``filament'' of the large scale structure.

12 pages, 20 .ps figures, accepted for pubblication in A&A

References in corpus (21)

• The Chandra Deep Field South: the 1 Million Second
• First Results from the X-ray and Optical Survey of the Chandra Deep Field South
• Halo Properties in Cosmological Simulations of Self-Interacting Cold Dark Matter
• Chandra Discovery of a Tree in the X-ray Forest towards PKS 2155-304: the Local Filament?
• New Results from the X-ray and Optical Survey of the Chandra Deep Field South: The 300ks Exposure
• Clustering Segregation With UV Luminosity in Lyman-Break Galaxies at z~3 and Its Implications
• Tracing the Warm-Hot Intergalactic Medium at Low Redshift: X-ray Forest Observations Towards H1821+643
• The X-ray -- radio alignment in the z = 2.2 radio galaxy PKS 1138--262
• The coincidence and angular clustering of Chandra and SCUBA sources
• An Unexpectedly High AGN Fraction in Red Cluster Galaxies
• The Spatial Clustering of Distant, z~1, Early-Type Galaxies
• Chandra study of an overdensity of X-ray sources around two distant (z~0.5) clusters
• Imaging Large Scale Structure in the X-ray Sky
• The evolution of the galaxy luminosity function in the rest frame blue band up to z=3.5
• Detection of the Angular Correlation of Faint X-ray Sources
• Warm-hot intergalactic baryons revealed
• Chandra Observations of Unresolved X-ray Sources around two Clusters of Galaxies
• The Evolution of the Luminosity Function in Deep Fields: A Comparison with CDM Models
• Micro-Jy radio sources in the z=0.83 cluster MS1054-03
• Missing baryons and the soft X-ray background
• Probing the warm Inter-Galactic Medium through absorption against Gamma Ray Bursts X-ray afterglows

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