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An accretion disk laboratory in the Seyfert 1.9 galaxy NGC 2992

Published online by Cambridge University Press:  01 August 2006

Tahir Yaqoob
Affiliation:
Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt Rd., Greenbelt, MD 20771, USA
Kendrah D. Murphy
Affiliation:
Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt Rd., Greenbelt, MD 20771, USA
Yuichi Terashima
Affiliation:
Department of Physics, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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Abstract

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Over twenty five years of X-ray observations of the Seyfert 1.9 galaxy NGC 2992 show that it is a promising test-bed for severely constraining accretion disk models. The previous interpretation of the historical activity of NGC 2992 in terms of the accretion disk slowly becoming dormant over many years and then ‘re-building’ itself is not supported by new data. A recent year-long monitoring campaign with RXTE showed that the X-ray continuum varied by more than an order of magnitude on a timescale of weeks. During the large-amplitude flares the centroid energy of the Fe K emission-line complex became significantly redshifted, indicating that the violent activity was occurring close to the putative central black hole where gravitational energy shifts can be sufficiently large. For the continuum, the Compton-y parameter remains roughly constant despite the large-amplitude luminosity variability, with (kT) τ ∼ 20–50.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2007

References

Gilli, R., Maiolino, R., Marconi, A. et al. 2000, A&A, 355, 485Google Scholar
Iwasawa, K., Fabian, A. C., Young, A. J. et al. 1999, MNRAS, 306, L19CrossRefGoogle Scholar
Keel, W. C. 1996, ApJS, 106, 27CrossRefGoogle Scholar
Piccinotti, G., Mushotzky, R. F., Boldt, E. A. et al. 1982 ApJ, 253, 485CrossRefGoogle Scholar
Titarchuk, L. 1994, ApJ, 434, 570CrossRefGoogle Scholar
Weaver, K. A., Nousek, J., Yaqoob, T. et al. 1996, ApJ, 458, 160CrossRefGoogle Scholar
Woo, J.-H. & Urry, C. M. 2002, ApJ, 579, 530CrossRefGoogle Scholar
Yaqoob, T., Murphy, K. D., Griffiths, R. E. et al. 2007, PASJ, 59S, 283CrossRefGoogle Scholar