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Durham University

Department of Physics

Staff profile

Publication details for Prof David Alexander

Xue, Y. Q., Luo, B., Brandt, W. N., Alexander, D. M., Bauer, F. E., Lehmer, B. D. & Yang, G. (2016). The 2 Ms Chandra Deep Field-North Survey and the 250 ks Extended Chandra Deep Field-South Survey: Improved Point-Source Catalogs. The Astrophysical Journal Supplement Series 224(2): 15.

Author(s) from Durham


We present improved point-source catalogs for the 2 Ms Chandra Deep Field-North (CDF-N) and the 250 ks Extended Chandra Deep Field-South (E-CDF-S) Surveys, implementing a number of recent improvements in Chandra source-cataloging methodology. For CDF-N/E-CDF-S, we provide a main catalog that contains 683/1003 X-ray sources detected with wavdetect at a false-positive probability threshold of 10−5 that also satisfy a binomial-probability source-selection criterion of $P\lt 0.004$/P < 0.002. Such an approach maximizes the number of reliable sources detected: a total of 196/275 main-catalog sources are new compared to the Alexander et al. CDF-N/Lehmer et al. E-CDF-S main catalogs. We also provide CDF-N/E-CDF-S supplementary catalogs that consist of 72/56 sources detected at the same wavdetect threshold and having P of 0.004–0.1/0.002–0.1 and ${K}_{s}\leqslant 22.9/{K}_{s}\leqslant 22.3$ mag counterparts. For all $\approx 1800$ CDF-N and E-CDF-S sources, including the $\approx 500$ newly detected ones (these being generally fainter and more obscured), we determine X-ray source positions utilizing centroid and matched-filter techniques; we also provide multiwavelength identifications, apparent magnitudes of counterparts, spectroscopic and/or photometric redshifts, basic source classifications, and estimates of observed active galactic nucleus and galaxy source densities around respective field centers. Simulations show that both the CDF-N and E-CDF-S main catalogs are highly reliable and reasonably complete. Background and sensitivity analyses indicate that the on-axis mean flux limits reached represent a factor of $\approx 1.5$–2.0 improvement over the previous CDF-N and E-CDF-S limits. We make our data products publicly available.