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The Continuum of Quasars and Active Galactic Nuclei, and Its Time Variability

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Reviews in Modern Astronomy

Part of the book series: Reviews in Modern Astronomy ((MOD.ASTRONOMY,volume 5))

Abstract

We review the origin of the continuum emission in radio quiet quasars and Seyfert 1 galaxies with particular emphasis on the X-ray domain 1–20 keV. We also include very recent results extending to 120 keV.

We point out that the UV continuum in Seyfert 1 galaxies is not predominantly radiation emitted by an undisturbed thin accretion disk. Irradiation of the surface of the disk by a rapidly varying X-ray source, or flares in the inner unstable regions of the disk, are the likely causes for the rapid variability of the UV flux. The fitting of the optical/UV spectrum of AGN with models which do not include these important effects appears less useful than originally thought and the inferred values of M and M may be in doubt.

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Author information

Authors and Affiliations

  1. European Southern Observatory, Karl-Schwarzschild-Str. 2, W-8046, Garching b. München, Germany

    M.-H. Ulrich

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  1. M.-H. Ulrich
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Editor information

Editors and Affiliations

  1. Landessternwarte, Königstuhl, D-6900, Heidelberg 1, Fed. Rep. of Germany

    Gerhard Klare

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© 1992 Springer-Verlag Berlin Heidelberg

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Ulrich, MH. (1992). The Continuum of Quasars and Active Galactic Nuclei, and Its Time Variability. In: Klare, G. (eds) Reviews in Modern Astronomy. Reviews in Modern Astronomy, vol 5. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-77543-7_17

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  • DOI: https://doi.org/10.1007/978-3-642-77543-7_17

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-642-77545-1

  • Online ISBN: 978-3-642-77543-7

  • eBook Packages: Springer Book Archive

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