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Active Galactic Nuclei: Variability at Many Wavelengths

Published online by Cambridge University Press:  14 August 2015

Thierry J.-L. Courvoisier
Thierry J.-L. Courvoisier*
Affiliation:
INTEGRAL Science Data Centres16, ch. d’Ecogia CH-1290 VersoixSwitzerland and Observatoire de GenèveCH-1290 SAUVERNYSwitzerland

Extract

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Active Galactic Nuclei (AGN) are thought to be powered by accretion onto a massive black hole. Understanding how gravitational energy freed by the infall of matter into the black hole is transferred to the radiating regions of the nucleus is one of the main challenges of AGN research. The question is made very complex by the presence of several cooling mechanisms with very diverse physical properties: We observe synchrotron radiation, thermal emission from hot dust, possibly thermal optical and ultraviolet emission and Comptonization processes in the X-ray domain. For each component the radiation is a signature of the cooling process rather than of the heating process. It is our hope that by observing the links and correlations between the emission of the different components we will be able to understand how they are interrelated and how they get their energy supply from the accretion process.

Type
II. Joint Discussions
Information
Highlights of Astronomy , Volume 11 , Issue 2: Highlights of Astronomy. As presented at the XXIIIrd General Assembly of the IAU (Part B), 1997 , 1998 , pp. 808 - 811
Copyright
Copyright © Kluwer 1998

References

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