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Durham University

Department of Physics

Staff profile

Publication details for Professor Ian Smail

Luo, B., Brandt, W.N., Xue, Y.Q., Lehmer, B., Alexander, D.M., Bauer, F.E., Vito, F., Yang, G., Basu-Zych, A.R., Comastri, A., Gilli, R., Gu, Q.-S., Hornschemeier, A.E., Koekemoer, A., Liu, T., Mainieri, V., Paolillo, M., Ranalli, P., Rosati, P., Schneider, D.P., Shemmer, O., Smail, I., Sun, M., Tozzi, P., Vignali, C. & Wang, J.-X. (2017). The Chandra Deep Field-South Survey: 7 Ms Source Catalogs. The Astrophysical Journal Supplement Series 228(1): 2.

Author(s) from Durham


We present X-ray source catalogs for the ≈7 Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2 arcmin2. Utilizing wavdetect for initial source detection and ACIS Extract for photometric extraction and significance assessment, we create a main source catalog containing 1008 sources that are detected in up to three X-ray bands: 0.5–7.0 keV, 0.5–2.0 keV, and 2–7 keV. A supplementary source catalog is also provided, including 47 lower-significance sources that have bright (${K}_{s}\leqslant 23$) near-infrared counterparts. We identify multiwavelength counterparts for 992 (98.4%) of the main-catalog sources, and we collect redshifts for 986 of these sources, including 653 spectroscopic redshifts and 333 photometric redshifts. Based on the X-ray and multiwavelength properties, we identify 711 active galactic nuclei (AGNs) from the main-catalog sources. Compared to the previous ≈4 Ms CDF-S catalogs, 291 of the main-catalog sources are new detections. We have achieved unprecedented X-ray sensitivity with average flux limits over the central ≈1 arcmin2 region of ≈1.9 × 10−17, 6.4 × 10−18, and 2.7 × 10−17 erg cm−2 s−1 in the three X-ray bands, respectively. We provide cumulative number-count measurements observing, for the first time, that normal galaxies start to dominate the X-ray source population at the faintest 0.5–2.0 keV flux levels. The highest X-ray source density reaches ≈50,500 deg−2, and 47% ± 4% of these sources are AGNs (≈23,900 deg−2).