The Chandra Deep Protocluster Survey : Point - Source Catalogs for a 400 ks Observation of the z = 3 . 09 Protocluster in SSA

We present X-ray point-source catalogs for a deep ≈400 ks Chandra ACIS-I exposure of the SSA22 field. The observations are centred on a z = 3.09 protocluster, which is populated by Lyman break galaxies (LBGs), Lyα emitters (LAEs), and extended Lyα-emitting blobs (LABs). The survey reaches ultimate (3 count) sensitivity limits of ≈5.7 ×10 ergs cm s and ≈3.0 ×10 ergs cm s for the 0.5–2 keV and 2–8 keV bands, respectively (corresponding to L2−10 keV ≈ 5.7 × 10 and L10−30 keV ≈ 2.0× 10 43 ergs s at z = 3.09, respectively, for an assumed photon index of Γ = 1.4). These limits make SSA22 the fourth deepest extragalactic Chandra survey yet conducted, and the only one focused on a known high redshift structure. In total, we detect 297 X-ray point sources and identify one obvious bright extended X-ray source over a ≈330 arcmin region. In addition to our X-ray catalogs, we provide all available optical spectroscopic redshifts and near-infrared and mid-infrared photometry available for our sources. The basic X-ray and infrared properties of our Chandra sources indicate a variety of source types, although absorbed active galactic nuclei (AGNs) appear to dominate. In total, we have identified 12 X-ray sources (either via optical spectroscopic redshifts or LAE selection) at z = 3.06–3.12 that are likely to be associated with the SSA22 protocluster. These sources have X-ray and multiwavelength properties that suggest they are powered by AGN with 0.5–8 keV luminosities in the range of ≈10–10 ergs s. We have analysed the AGN fraction of sources in the protocluster as a function of local LAE source density and find suggestive evidence for a correlation between AGN fraction and local LAE source density (at the ≈96 per cent confidence level), implying that supermassive black hole growth at z ≈ 3 is strongest in the highest density regions.