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AGN Variability

Published online by Cambridge University Press:  25 May 2016

Toshihiro Kawaguchi  and
Shin Mineshige
Toshihiro Kawaguchi
Affiliation:
Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
Shin Mineshige
Affiliation:
Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan

Abstract

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A number of monitoring observations of continuum emission from Active Galactic Nuclei (AGNs) have been made in optical-X-ray bands. The results obtained so far show (i) random up and down on timescales longer than decades, (ii) no typical timescales of variability on shorter timescales and (iii) decreasing amplitudes as timescales become shorter. The second feature indicates that any successful model must produce a wide variety of shot-amplitudes and -durations over a few orders in their light curves. In this sense, we conclude that the disk instability model is favored over the starburst model, since fluctuations on days are hard to produce by the latter model.

Inter-band correlations and time lags also impose great constraints on models. Thus, constructing wavelength and time dependent models remains as future work.

Type
IV. AGN Related Phenomena
Information
Symposium - International Astronomical Union , Volume 194: Activity in Galaxies and Related Phenomena , 1999 , pp. 356 - 363
Copyright
Copyright © Astronomical Society of the Pacific 1999 

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