2013/02/07 by G. Lanzuisi, F. Civano, M. Elvis +17 · 74 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Cosmos (plant) #Galaxies: Formation, Evolution, Phenomena #Optics #Physics #Sample (material) #Spectral line #Stellar, planetary, and galactic studies #X-ray #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stt222
published in Monthly Notices of the Royal Astronomical Society 431(1), 978-996 (Oxford University Press) · 20 pages, 16 figures. Accepted for Pubblication in MNRAS, 2013 February 5
arxiv created 2013/02/07 · openalex publication_date 2013/03/09 · arxiv updated 2015/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present the X-ray spectral analysis of the 390 brightest extragalactic sources in the Chandra-Cosmic Evolution Survey catalogue, showing at least 70 net counts in the 0.5–7 keV band. This sample has a 100 per cent completeness in optical–infrared identification, with ∼75 per cent of the sample having a spectroscopic redshift and ∼25 per cent a photometric redshift. Our analysis allows us to accurately determine the intrinsic absorption, the broad-band continuum shape (Γ) and intrinsic L2–10 distributions, with an accuracy better than 30 per cent on the spectral parameters for 95 per cent of the sample. The sample is equally divided in type 1 (49.7 per cent) and type 2 active galactic nuclei (48.7 per cent) plus few passive galaxies at low z. We found a significant difference in the distribution of Γ of type 1 and type 2, with small intrinsic dispersion, a weak correlation of Γ with L2−10 and a large population (15 per cent of the sample) of high luminosity, highly obscured (QSO2) sources. The distribution of the X-ray/Optical flux ratio (Log(FX/Fi)) for type 1 is narrow (0 < X/O < 1), while type 2 are spread up to X/O = 2. The X/O correlates well with the amount of X-ray obscuration. Finally, a small sample of Compton-thick candidates and peculiar sources is presented. In the appendix, we discuss the comparison between Chandra and XMM–Newton spectra for 280 sources in common. We found a small systematic difference, with XMM–Newton spectra that tend to have softer power laws and lower obscuration.