We present a statistical analysis of the Chandra observation of the source field around the 3C 295 galaxy cluster (z=0.46). The logN-logS of this field is in good agreement with that computed for the Chandra Deep Field South in this work and in previous ones. Nevertheless, the logN-logS computed separately for the four ACIS-I chips reveals that there is a significant excess of sources to the North-North East and a void to the South of the central cluster. Such an asymmetric distribution is confirmed by the two-dimensional Kolmogorov-Smirnov test, which excludes (P~3%) a uniform distribution. In addition, a strong spatial correlation emerges from the study of the angular correlation function of the field: the angular correlation function is above that expected for X-ray sources on a few arcmin scales. In synthesis, the present analysis may indicate a filament of the large scale structure of the Universe toward 3C 295. This kind of study may open-up a new way to map (with high efficiency) high-density peaks of large scale structures at high redshift.
D'Elia, V., Fiore, F., Elvis, M., Cappi, M., Mathur, S., Mazzotta, P., et al. (2004). X-ray sources overdensity around the 3C 295 galaxy cluster. NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS, 132, 54-57 [10.1016/j.nuclphysbps.2004.04.007].
X-ray sources overdensity around the 3C 295 galaxy cluster
MAZZOTTA, PASQUALE;
2004-01-01
Abstract
We present a statistical analysis of the Chandra observation of the source field around the 3C 295 galaxy cluster (z=0.46). The logN-logS of this field is in good agreement with that computed for the Chandra Deep Field South in this work and in previous ones. Nevertheless, the logN-logS computed separately for the four ACIS-I chips reveals that there is a significant excess of sources to the North-North East and a void to the South of the central cluster. Such an asymmetric distribution is confirmed by the two-dimensional Kolmogorov-Smirnov test, which excludes (P~3%) a uniform distribution. In addition, a strong spatial correlation emerges from the study of the angular correlation function of the field: the angular correlation function is above that expected for X-ray sources on a few arcmin scales. In synthesis, the present analysis may indicate a filament of the large scale structure of the Universe toward 3C 295. This kind of study may open-up a new way to map (with high efficiency) high-density peaks of large scale structures at high redshift.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
