@inproceedings{abc638ffbac44feebb8fc4171a391f27,
title = "Resolving the X-ray background",
abstract = "We have stacked the X-ray emission from X-ray-detected sources in ∼ 3.8 Ms of Chandra Deep Field and XMM-Newton Lockman Hole observations. The fraction of the X-ray background which can be resolved into point sources is ∼ 70-90\% up to 4 keV. In the 6-8 keV band this fraction decreases to ∼ 50-70\% and XMM-Newton indicates only ∼ 40-60\% in the 8-12 keV range. The unresolved fraction is consistent with an undiscovered population of highly obscured AGN. To attempt to uncover this population we proceeded to stack the X-ray emission from the X-ray-undetected optical sources in the Chandra Deep Fields, using Hubble source positions from the Great Observatories Origins Deep Survey. In the 0.5-6 keV range the stacked-source emission corresponds to the remaining 10-20\% of the X-ray background. In the 6-8 keV band we find upper limits to the stacked X-ray flux consistent with the remaining ∼ 40\% of the background, but the errors are too large to claim a detection of the obscured AGN population.",
author = "Worsley, \{M. A.\} and Fabian, \{A. C.\} and Alexander, \{D. M.\} and Bauer, \{F. E.\} and Brandt, \{W. N.\} and G. Hasinger and Lehmer, \{B. D.\}",
year = "2005",
month = nov,
day = "22",
doi = "10.1063/1.2141832",
language = "English (US)",
isbn = "0735402906",
series = "AIP Conference Proceedings",
pages = "51--56",
booktitle = "Astrophysical Sources of High Energy Particles and Radiation",
note = "Astrophysical Sources of High Energy Particles and Radiation ; Conference date: 20-06-2005 Through 24-06-2005",
}