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Title: XMM Newton Observations of Red AGNs
Authors: Wilkes, J. B.
Pounds, Kenneth Alwyne
Schmidt, G. D.
Smith, P. S.
Cutri, R. M.
Ghosh, H.
Nelson, B.
Hines, D. C.
First Published: 20-Nov-2005
Publisher: IOP Publishing, American Astronomical Society
Citation: Astrophysical Journal, 2005, 634 (1), pp. 183-192
Abstract: XMM-Newton spectra of five red 2MASS active galactic nuclei (AGNs), selected from a sample observed by Chandra to be relatively X-ray bright and to cover a range of hardness ratios, confirm the presence of substantial absorbing material in three sources with optical classifications ranging from type 1 to type 2. A flat (hard) power-law continuum is observed in the other two. The combination of X-ray absorption and broad optical emission lines suggests either a small (nuclear) absorber or a favored viewing angle so as to cover the X-ray source but not the broad emission-line region (BELR). A soft excess is detected in all three type 1 sources. We speculate that this may arise in an extended region of ionized gas, perhaps linked to the polarized (scattered) optical light present in these sources. The spectral complexity revealed by XMM-Newton emphasizes the limitations of the low-S/N Chandra data. The new results strengthen our earlier conclusions that the observed X-ray continua of red AGNs are unusually hard at energies gsim2 keV. Their observed spectra are consistent with contributing significantly to the missing hard or absorbed population of the cosmic X-ray background (CXRB), although their intrinsic power-law slopes are typical of broad-line (type 1) AGNs (Γ ~ 1.7-1.9). This suggests that the missing X-ray-absorbed CXRB population may include type 1 AGNs or QSOs in addition to the type 2 AGNs generally assumed.
DOI Link: 10.1086/444555
ISSN: 0004-637X
eISSN: 1538-4357
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2005. The American Astronomical Society. All rights reserved. Deposited with reference to the publisher’s archiving policy available on the SHERPA/RoMEO website.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

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