Absorption Properties and Evolution of Active Galactic Nuclei

Understand

Intrinsic absorption is a fundamental physical property to understand the evolution of active galactic nuclei (AGN).

• Here a sample of 1290 AGN, selected in the 2-10 keV band from different flux-limited surveys with very high optical identification completeness is studied.
• The AGN are grouped into two classes, unabsorbed (type-1) and absorbed (type-2), depending on their optical spectroscopic classification and X-ray absorption properties, using hardness ratios.
• Utilizing the optical to X-ray flux ratios, a rough correction for the ~8% redshift incompleteness still present in the sample is applied.