X-RAY SPECTRAL VARIABILITY IN NGC 3783
- Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)
- Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom)
- Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
- Harvard-Smithsonian CfA, 60 Garden Street MS-67, Cambridge, MA 02138 (United States)
- MIT Kavli Institute for Astrophysics, Cambridge, MA 02139 (United States)
NGC 3783 was observed for approximately 210 ks by Suzaku and in this time showed significant spectral and flux variability at both short (20 ks) and long (100 ks) timescales. The full observation is found to consist of approximately six 'spectral periods' where the behavior of the soft (0.3-1.0 keV) and hard (2-10 keV) bands are somewhat distinct. Using a variety of methods we find that the strong warm absorber present in this source does not change on these timescales, confirming that the broadband variability is intrinsic to the central source. The time-resolved difference-spectra are well modeled with an absorbed power law below 10 keV, but show an additional hard excess at Almost-Equal-To 20 keV in the latter stages of the observation. This suggests that, in addition to the variable power law, there is a further variable component that varies with time but not monotonically with flux. We show that a likely interpretation is that this further component is associated with variations in the reflection fraction or possibly ionization state of the accretion disk a few gravitational radii from the black hole.
- OSTI ID:
- 22011948
- Journal Information:
- Astrophysical Journal, Vol. 745, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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