The Extended Chandra Deep Field–South Survey: Chandra Point‐Source Catalogs

We present Chandra point-source catalogs for the Extended Chandra Deep Field-South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250 ks Chandra observations covering an approximately square region of total solid angle ≈0.3 deg 2 , which flank the existing ≈1 Ms Chandra Deep Field-South (CDF-S). The survey reaches sensitivity limits of ≈1.1 × 10 -16 and ≈6.7 × 10 -16 ergs cm -2 s -1 for the 0.5-2.0 and 2-8 keV bands, respectively. We detect 762 distinct X-ray point sources within the E-CDF-S exposure; 589 of these sources are new (i.e., not previously detected in the ≈1 Ms CDF-S). This brings the total number of X-ray point sources detected in the E-CDF-S region to 915 (via the E-CDF-S and ≈1 Ms CDF-S observations). Source positions are determined using matched-filter and centroiding techniques; the median positional uncertainty is ≈0 35. The basic X-ray and optical properties of these sources indicate a variety of source types, although absorbed active galactic nuclei (AGNs) seem to dominate. In addition to our main Chandra catalog, we constructed a supplementary source catalog containing 33 lower significance X-ray point sources that have bright optical counterparts ( R < 23). These sources generally have X-ray-to-optical flux ratios expected for normal and starburst galaxies, which lack a strong AGN component. We present basic number-count results for our main Chandra catalog and find good agreement with the ≈1 Ms CDF-S for sources with 0.5-2.0 and 2-8 keV fluxes greater than 3 × 10 -16 and 1 × 10 -15 ergs cm -2 s -1 , respectively. Furthermore, three extended sources are detected in the 0.5-2.0 keV band, which are found to be likely associated with galaxy groups or poor clusters at z ≈ 0.1-0.7; these have typical rest-frame 0.5-2.0 keV luminosities of (1-5) × 10 42 ergs s -1 .