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Description
This table contains the observed-frame optical, near-infrared, and mid-infrared properties of X-ray-selected active galactic nuclei (AGN) in the Lockman Hole. Using a likelihood ratio method on optical, near-infrared or mid-infrared catalogs, the authors assigned counterparts to 401 out of the 409 X-ray sources of the XMM-Newton catalog (Brunner et al. 2008, A&A, 479, 283). Accurate photometry was collected for all the sources from U to 24 microns. The authors used X-ray and optical criteria to remove any normal galaxies, galactic stars, or X-ray clusters among them and studied the multi-wavelength properties of the remaining 377 AGN in their paper. They used a mid-IR colour-colour selection to understand the AGN contribution to the optical and infrared emission. Using this selection, they identified different behaviours of AGN-dominated and host-dominated sources in X-ray-optical-infrared color-color diagrams. More specifically, the AGN-dominated sources show a clear trend in the f<sub>x</sub>/f<sub>RC</sub> vs. R<sub>C</sub> - K and f<sub>24um</sub>/f<sub>RC</sub> vs. R<sub>C</sub> - K diagrams, while the hosts follow the behaviour of non-X-ray detected galaxies. In the optical-near-infrared color-magnitude diagram, the known trend of redder objects to be more obscured in X-rays is seen to be stronger for AGN-dominated than for host-dominated systems. This is an indication that the trend is more related to the AGN, which contaminate the overall colors, than to any evolutionary effects, the authors believe. Finally, the authors find that a significant fraction (~30%) of the reddest AGN are not obscured in X-rays. The X-ray observations of the Lockman Hole took place between April 2000 and December 2002 with XMM-Newton. The optical observations of the Lockman Hole were conducted with the Large Binocular Telescope (U, B, V bands) and the Subaru Telescope (R<sub>C</sub>, I<sub>C</sub>, z' bands). The LBT observations were taken from February 2007 to March 2009. The R<sub>C</sub>, I<sub>C</sub>, and z' bands have been observed with the Suprime-Cam of the Subaru telescope between November 2001 and April 2002. This table contains the properties of the counterparts to all 409 X-ray sources listed in the Lockman Hole XMM-Newton source catalog of Brunner et al. (2008, A&A, 479, 283), including the 377 AGN and also the 32 objects classified as Galactic stars, galaxy clusters or galaxies. For 8 (2%) of the 409 X-ray sources no optical or IR counterparts were found. These 8 objects are listed in this table with null positional values. This table was created by the HEASARC in January 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/529/A135">CDS Catalog J/A+A/529/A135</a> file table2.dat. This is a service provided by NASA HEASARC .
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