http://arxiv.org/abs/2304.13159
We present an extensive and well-characterized Chandra X-ray Galaxy Catalog (CGC) of 8557 galaxy candidates in the redshift range z ~ 0.04 – 0.7, optical luminosity 1010 – 1011 Lro, and X-ray luminosity (0.5-7 keV) LX = 2×1040 – 2×1043 erg s-1. We estimate ~5% false match fraction and contamination by QSOs. The CGC was extracted from the Chandra Source Catalog version 2 (CSC2) by cross-correlating with optical and IR all-sky survey data, including SDSS, PanSTARRS, DESI Legacy, and WISE. Our selection makes use of two main criteria that we have tested on the subsample with optical spectroscopical identification. (1) A joint selection based on X-ray luminosity (LX) and X-ray to optical flux ratio (FXO), which recovers 63% of the spectroscopically classified galaxies with a small contamination fraction (7%), a significant improvement over methods using LX or FXO alone (< 50% recovery). (2) A joint W1-W2 (W12) WISE color and LX selection that proves effective in excluding QSOs and improves our selection by recovering 72% of the spectroscopically classified galaxies and reducing the contamination fraction (4%). Of the CGC, 24% was selected by means of optical spectroscopy; 30% on the basis of LX, FXO, and W12; and 46% by using either the LX-FXO or the LX-W12 selection criteria. We have individually examined the data for galaxies with z < 0.1, which may include more than one CSC2 X-ray source, leading to the exclusion of 110 local galaxies. Our catalog also includes near-IR and UV data and galaxy morphological types.
D. Kim, A. Cassity, B. Bhatt, et. al.
Thu, 27 Apr 23
54/78
Comments: submitted ApJS, 35 pages, 11 figures
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