AEGIS-X: Deep Chandra imaging of the Central Groth Strip
astro-ph.HE
/ Authors
K. Nandra, E. S. Laird, J. A. Aird, M. Salvato, A. Georgakakis, G. Barro, P. G. Perez Gonzalez, P. Barmby, R. -R. Chary, A. Coil
and 15 more authors
M. C. Cooper, M. Davis, M. Dickinson, S. M. Faber, G. G. Fazio, P. Guhathakurta, S. Gwyn, L. -T. Hsu, J. -S. Huang, R. J. Ivison, D. C. Koo, J. A. Newman, C. Rangel, T. Yamada, C. Willmer
/ Abstract
We present the results of deep \chandra\ imaging of the central region of the Extended Groth Strip, the AEGIS-X Deep (AEGIS-XD) survey. When combined with previous \chandra\ observations of a wider area of the strip, AEGIS-X Wide (AEGIS-XW; Laird et~al. 2009), these provide data to a nominal exposure depth of 800ks in the three central ACIS-I fields, a region of approximately $0.29$~deg$^{2}$. This is currently the third deepest X-ray survey in existence, a factor $\sim 2-3$ shallower than the Chandra Deep Fields (CDFs) but over an area $\sim 3$ times greater than each CDF. We present a catalogue of 937 point sources detected in the deep \chandra\ observations. We present identifications of our X-ray sources from deep ground-based, Spitzer, GALEX and HST imaging. Using a likelihood ratio analysis, we associate multi band counterparts for 929/937 of our X-ray sources, with an estimated 95~\% reliability, making the identification completeness approximately 94~\% in a statistical sense. Reliable spectroscopic redshifts for 353 of our X-ray sources are provided predominantly from Keck (DEEP2/3) and MMT Hectospec, so the current spectroscopic completeness is $\sim 38$~per cent. For the remainder of the X-ray sources, we compute photometric redshifts based on multi-band photometry in up to 35 bands from the UV to mid-IR. Particular attention is given to the fact that the vast majority the X-ray sources are AGN and require hybrid templates. Our photometric redshifts have mean accuracy of $σ=0.04$ and an outlier fraction of approximately 5\%, reaching $σ=0.03$ with less than 4\% outliers in the area covered by CANDELS . The X-ray, multi-wavelength photometry and redshift catalogues are made publicly available.