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AGN Properties and Their Contribution to the Cosmic X-Ray Background

Published online by Cambridge University Press:  12 April 2016

M. Matsuoka
M. Matsuoka*
Affiliation:
The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01, Japan

Abstract

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We have investigated the characteristics of AGN using data from ASCA X-ray observations and considered their contribution to the CXB. There are mainly four specific topics that need to be considered: (1) the absorption edges due to warm gas, (2) the complex spectra of Seyfert 2 galaxies, (3) the broad iron emission line, and (4) the soft X-ray excess.

The CXB can be explained by superposing AGN spectra according to cosmological distance, but so far the distant quasars (z > 1) that have been observed show spectra in the 2–10 keV band that are steeper than the spectrum of the CXB. Recent observations have been more clearly defining the properties of the AGN one by one. We have more than 80 high-quality AGN spectra, but their properties are not well-balanced due to poor sampling of low-luminosity AGN. A large number of lowluminosity AGN might be the main contributors to the CXB.

Type
X. Unification of Active Galaxies and Other Global Issues
Information
International Astronomical Union Colloquium , Volume 159: Emission Lines in Active Galaxies: New Methods and Techniques , 1997 , pp. 487 - 488
Copyright
Copyright © Astronomical Society of the Pacific 1997

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