The Chandra Deep Wide-Field Survey: A New Chandra Legacy Survey in the Boötes Field I. X-ray Point Source Catalog, Number Counts and Multi-Wavelength Counterparts

Abstract

We present a new, ambitious survey performed with the Chandra X-ray Observatory of the 9.3 deg${}^2$ Boötes field of the NOAO Deep Wide-Field Survey. The wide field probes a statistically representative volume of the Universe at high redshift. The Chandra Deep Wide-Field Survey exploits the excellent sensitivity and angular resolution of Chandra over a wide area, combining 281 observations spanning 15 years, for a total exposure time of 3.4 Ms, and detects 6891 X-ray point sources down to limiting fluxes of $4.7\times 10^{-16}$, $1.5\times 10^{-16}$, and $9\times 10^{-16}$ erg cm${}^{-2}$ s${}^{-1}$, in the $0.5-7$ keV, $0.5-2$ keV, and $2-7$ keV bands, respectively. The robustness and reliability of the detection strategy is validated through extensive, state-of-the-art simulations of the whole field. Accurate number counts, in good agreement with previous X-ray surveys, are derived thanks to the uniquely large number of point sources detected, which resolve $65.0\pm 12.8\%$ of the cosmic X-ray background between $0.5-2$ keV and $81.0\pm 11.5\%$ between $2-7$ keV. Exploiting the wealth of multi-wavelength data available on the field, we assign redshifts to $\sim 94\%$ of the X-ray sources, estimate their obscuration and derive absorption-corrected luminosities. We provide an electronic catalog containing all the relevant quantities needed for future investigations.

Accepted for publication in ApJS. The catalogs associated to this paper can be accessed at http://www.dartmouth.edu/~hickox/cdwfs.php