Hostname: page-component-77c89778f8-fv566 Total loading time: 0 Render date: 2024-07-18T10:37:00.815Z Has data issue: false hasContentIssue false
  • English
  • Français

Soft X-ray Variability and the Covering Fraction of Active Galactic Nuclei

Published online by Cambridge University Press:  07 August 2017

Michael A. Strauss ,
Kenneth W. Wachter  and
Alexei V. Filippenko
Michael A. Strauss
Affiliation:
Department of Astronomy, University of California, Berkeley, CA 94720 U.S.A.
Kenneth W. Wachter
Affiliation:
Department of Astronomy, University of California, Berkeley, CA 94720 U.S.A.
Alexei V. Filippenko
Affiliation:
Department of Astronomy, University of California, Berkeley, CA 94720 U.S.A.

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The variability of soft X-rays (0.2 – 2 keV) in some low-luminosity type 1 Seyferts may partly be due to an extrinsic mechanism: dense clouds of gas in the broad-line region, opaque to soft X-rays, move across our line of sight to the X-ray emitting portions of the accretion disk (Reichert, Mushotzky, and Holt 1986; Lawrence and Elvis 1982; Halpern 1984). As the clouds move, the covering fraction changes stochastically. Evidence for partial covering of the X-ray source in low-luminosity AGNs has been seen in soft X-ray spectra by Holt et al. (1980) and Reichert et al. (1985).

Type
Part 2: BLR and Variability
Information
Symposium - International Astronomical Union , Volume 134: Active Galactic Nuclei , 1989 , pp. 118 - 119
Copyright
Copyright © Kluwer 1989 

References

Halpern, J. P. 1984, Ap. J., 281, 90.Google Scholar
Holt, S. S. et al. 1980, Ap. J. (Letters), 241, L13.Google Scholar
Lawrence, A., and Elvis, M. 1982, Ap. J., 256, 410.CrossRefGoogle Scholar
Reichert, G. A., Mushotzky, R. F., and Holt, S. S. 1986, Ap. J., 303, 87.CrossRefGoogle Scholar
Reichert, G. A., Mushotzky, R. F., Petre, R., and Holt, S. S. 1985, Ap. J., 296, 69.Google Scholar
Shakura, N. I., and Sunyaev, R. A. 1973, Astr. Ap., 24, 337.Google Scholar
Wachter, K.W., Strauss, M.A., and Filippenko, A.V. 1988, Ap. J., 330, 91.Google Scholar