AEGIS-X: Deep Chandra imaging of the central groth strip

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, 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. IvisonD. C. Koo, J. A. Newman, C. Rangel, T. Yamada, C. Willmer

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56 Citations (Scopus)


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), these provide data to a nominal exposure depth of 800 ks in the three central ACIS-I fields, a region of approximately 0.29 deg2. This is currently the third deepest X-ray survey in existence; a factor shallower than the Chandra Deep Fields (CDFs), but over an area ∼3 times greater than each CDF. We present a catalog of 937 point sources detected in the deep Chandra observations, along with identifications of our X-ray sources from deep ground-based, Spitzer, GALEX, and Hubble Space Telescope imaging. Using a likelihood ratio analysis, we associate multiband 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 available predominantly from Keck (DEEP2/3) and MMT Hectospec, so the current spectroscopic completeness is ∼38%. For the remainder of the X-ray sources, we compute photometric redshifts based on multiband 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 active galactic nuclei and require hybrid templates. Our photometric redshifts have mean accuracy of and an outlier fraction of approximately 5%, reaching with less than 4% outliers in the area covered by CANDELS . The X-ray, multiwavelength photometry, and redshift catalogs are made publicly available.

Original languageEnglish
Article number10
JournalAstrophysical Journal, Supplement Series
Issue number1
Publication statusPublished - 2015 Sep 1


  • galaxies: active
  • galaxies: nuclei
  • surveys

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Nandra, K., Laird, E. S., Aird, J. A., Salvato, M., Georgakakis, A., Barro, G., Perez-Gonzalez, P. G., Barmby, P., Chary, R. R., Coil, A., Cooper, M. C., Davis, M., Dickinson, M., Faber, S. M., Fazio, G. G., Guhathakurta, P., Gwyn, S., Hsu, L. T., Huang, J. S., ... Willmer, C. (2015). AEGIS-X: Deep Chandra imaging of the central groth strip. Astrophysical Journal, Supplement Series, 220(1), [10].