The XMM deep survey in the CDF-S II. a 9-20 keV selection of heavily obscured active galaxies at z>1.7

2012/09/05 by K. Iwasawa, R. Gilli, C. Vignali +15
Physics and Astronomy · #Active galactic nucleus #Adaptive optics and wavefront sensing #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Chandra Deep Field South #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Luminosity function #Physics #Quasar #Redshift #Rest frame #Spectral line #Stars #astro-ph.CO

paper · pdf · doi:10.1051/0004-6361/201220036

9 pages, 7 figures. Accepted for publication in A&A

arxiv created 2012/09/05 · openalex publication_date 2012/09/05 · arxiv updated 2015/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We present results on a search of heavily obscured active galaxies z>1.7 using the rest-frame 9-20 keV excess for X-ray sources detected in the deep XMM-CDFS survey. Out of 176 sources selected with the conservative detection criteria (>8 sigma) in the first source catalogue of Ranalli et al., 46 objects lie in the redshift range of interest with the median redshift z~2.5. Their typical rest-frame 10-20 keV luminosity is 1e+44 erg/s, as observed. Among optically faint objects that lack spectroscopic redshift, four were found to be strongly absorbed X-ray sources, and the enhanced Fe K emission or absorption features in their X-ray spectra were used to obtain X-ray spectroscopic redshifts. Using the X-ray colour-colour diagram based on the rest-frame 3-5 keV, 5-9 keV, and 9-20 keV bands, seven objects were selected for their 9-20 keV excess and were found to be strongly absorbed X-ray sources with column density of nH > 0.6e+24 cm-2, including two possible Compton thick sources. While they are emitting at quasar luminosity, ~3/4 of the sample objects are found to be absorbed by nH > 1e+22 cm-2. A comparison with local AGN at the matched luminosity suggests an increasing trend of the absorbed source fraction for high-luminosity AGN towards high redshifts.

Citations

• A Physical Model for the Origin of Quasar Lifetimes
• Do nuclear starbursts obscure the X-ray background?
• IDENTIFICATIONS AND PHOTOMETRIC REDSHIFTS OF THE 2 Ms CHANDRA DEEP FIELD-SOUTH SOURCES
• The Blast Wave Model for AGN Feedback: Effects on AGN Obscuration
• Matplotlib: A 2D Graphics Environment
• The obscuration by dust of most of the growth of supermassive black holes
• The Evolution of Obscuration in Active Galactic Nuclei
• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• C-GOALS:Chandraobservations of a complete sample of luminous infrared galaxies from the IRAS Revised Bright Galaxy Survey
• X-ray spectra transmitted through Compton-thick absorbers
• H I in the Galaxy
• DISCOVERY OF STRONG IRON Kα EMITTING COMPTON THICK QUASARS AT z = 2.5 AND 2.9
• The XMM-Newton and BeppoSAX view of the Ultra Luminous Infrared Galaxy MKN 231
• Bootstrap Methods: Another Look at the Jackknife
• The great observatories origins deep survey
• Local supermassive black holes, relics of active galactic nuclei and the X-ray background
• A PUBLIC, K -SELECTED, OPTICAL-TO-NEAR-INFRARED CATALOG OF THE EXTENDED CHANDRA DEEP FIELD SOUTH (ECDFS) FROM THE MULTIWAVELENGTH SURVEY BY YALE-CHILE (MUSYC)
• The Chandra Deep Field–South: Optical Spectroscopy. I.
• On characterizing the variability properties of X-ray light curves from active galaxies
• Absorption properties and evolution of active galactic nuclei
• The Great Observatories Origins Deep Survey
• The XMM Deep Survey in the CDF-S
• XMM-Newton observations of the Lockman Hole
• The HELLAS2XMM survey
• The XMM deep survey in the CDF-S