The 174 ks Chandra Advanced CCD Imaging Spectrometer exposure of the Large Area Lyman Alpha Survey ( LALA ) Cetus field is the second of the two deep Chandra images on LALA fields .
In this paper we present the Chandra X-ray sources detected in the Cetus field , along with an analysis of X-ray source counts , stacked X-ray spectrum , and optical identifications .
A total of 188 X-ray sources were detected : 174 in the 0.5 – 7.0 keV band , 154 in the 0.5 – 2.0 keV band , and 113 in the 2.0 – 7.0 keV band .
The X-ray source counts were derived and compared with LALA Boötes field ( 172 ks exposure ) .
Interestingly , we find consistent hard band X-ray source density , but 36 \pm 12 % higher soft band X-ray source density in Cetus field .
The weighted stacked spectrum of the detected X-ray sources can be fitted by a powerlaw with photon index \Gamma = 1.55 .
Based on the weighted stacked spectrum , we find that the resolved fraction of the X-ray background drops from 72 \pm 1 % at 0.5 – 1.0 keV to 63 \pm 4 % at 6.0 – 8.0 keV .
The unresolved spectrum can be fitted by a powerlaw over the range 0.5 – 7 keV , with a photon index \Gamma = 1.22 .
We also present optical counterparts for 154 of the X-ray sources , down to a limiting magnitude of r ’ = 25.9 ( Vega ) , using a deep r ’ band image obtained with the MMT .