Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-04-14
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
6 pages, 2 figures. Invited talk at the conference "X-ray Astronomy 2009: Present status, multiwavelength approach and future
Scientific paper
Our current understanding of the evolution of obscured accretion onto supermassive black holes is reviewed. We consider the literature results on the relation between the fraction of moderately obscured, Compton-thin AGN and redshift, and discuss the biases which possibly affect the various measurements. Then, we discuss a number of methods - from ultradeep X-ray observations to the detection of high-ionization optical emission lines - to select the population of the most heavily obscured, Compton-thick AGN, whose cosmological evolution is basically unknown. The space density of heavily obscured AGN measured through different techniques is discussed and compared with the predictions by current synthesis models of the X-ray background. Preliminary results from the first half of the 3 Ms XMM observation of the Chandra Deep Field South (CDFS) are also presented. The prospects for population studies of heavily obscured AGN with future planned or proposed X-ray missions are finally discussed.
Comastri Andrea
Gilli Roberto
Iwasawa Kashuzi
Ranalli Piero
Vignali Christian
No associations
LandOfFree
The evolution of obscured accretion does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The evolution of obscured accretion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The evolution of obscured accretion will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-527940