|
Description
This table contains optical spectroscopic identifications of X-ray sources in ~3 square degrees of the XMM-Large Scale Structure survey (XMM-LSS), also covered by the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS), which were obtained with the AAOmega instrument at the 3.9-m Anglo-Australian Telescope during the nights of 2006 September 25-27 and 2007 September 11-13. In a flux-limited sample of 829 point-like sources in the optical band with g' <= 22 magnitudes and the 0.5-2 keV flux (f_0.5-2keV) > 10<sup>-15</sup> erg/cm<sup>2</sup>/s, the authors observed 693 objects and obtained reliable spectroscopic identification for 487 sources, approximately 59% of the overall sample. The authors therefore have increased the number of identifications in this field by a factor close to 5. Galactic stellar sources represent about 15% of the total (74/487). About 54% (265/487) are broad-line active galactic nuclei (AGN) spanning redshifts between 0.15 and 3.87 with a median value of 1.68. The optical-to-X-ray spectral index (alpha_ox) of the broad-line AGN is 1.47 +/- 0.03, typical of optically selected type I quasars, and is found to correlate with the rest-frame X-ray and optical monochromatic luminosities at 2 keV and 2500 Angstroms, respectively. Consistent with previous studies, the authors find that alpha_ox is not correlated with z. In addition, 32 and 116 X-ray sources are, respectively, absorption- and emission-line galaxies at z < 0.76. From a line ratio diagnostic diagram, it is found that in about 50% of these emission-line galaxies, the emission lines are powered significantly by the AGN. 30 of the XMM sources are detected at one or more radio frequencies (see Table 5 in the published paper). In addition, 24 sources (listed in table 4 of the published paper) have ambiguous identification: in eight cases, two XMM sources have a single optical source within 6 arcsec of each of them, whereas two and 14 XMM sources have, respectively, three and two possible optical sources within 6 arcsec of each of them. Spectra of multiple possible counterparts were obtained in such ambiguous cases. This HEASARC table contains the 487 sources which were reliably spectroscopically identified. This table was created by the HEASARC in July 2010 based on the CDS Catalog J/MNRAS/401/294 file table2.dat. This is a service provided by NASA HEASARC .
|
