Wide-band X-ray spectral and timing analysis of AGNs
Abstract
X-ray spectra of AGNs contain conplex features such as the continuum, emission line, ab-sorption, reflection component, high energy cut-off. These features are thought to reflect the material structure around AGN, and X-ray studies can clarify a physical geometry of AGNs. Especially, the hard X-ray observation above 10 keV is important to measure the reflection component. So far, hard X-ray studies of time variation of AGN spectra have been limited because of high background rate. Suzaku HXD achieve the highest S/N ratio by an effective background rejection. Combining the data with the XIS soft X-ray date, we can study the AGN X-ray spectra in more detail than ever. Here, we report the spectral and timing analysis of 14 Seyfert galaxies observed with Suzaku, in order to decompose each spectral component. The reflection component via a torus is considered to be less variable, while the varible component is considered to come from the central engine directly. Using this consideration, we tried to decompose a direct component and a reflection component. We compared the spectral parameters obtained by spectral fitting with direct nuclear plus reflection with those obtained from the difference spectra between high and low state. In particular, we forcus attention on the power-law index, reflection fraction, and the Fe-Ka line. As a result, the photon index, the Fe line intensity, and the refrection component is almost the same between high and low state. However, some of them are not the case, and the equivalent width of Fe-Ka line against the best-fit reflection component is unreasonable for some objects. These indicate that two-component model is valid for most of Seyfert galaxies, but the behavior of some Seyfert galaxies cannot be explained by two-conmponent model. Highly ionized Fe-K lines are observed as both emission and absorption, and some objects show a time variability of these lines. We will report this matter.
- Publication:
-
38th COSPAR Scientific Assembly
- Pub Date:
- 2010
- Bibcode:
- 2010cosp...38.2255H