Constraining the Spin of the Black Hole in Fairall 9 with Suzaku
Fabian, A. C.; Miller, J. M.; Reynolds, C. S.; Miniutti, G.; Gallo, L. C.; Brenneman, L. W.; Cackett, E.; Volonteri, M.; Schmoll, S.
United States, United Kingdom, Germany, France, Spain, Canada
Abstract
We report on the results of spectral fits made to data obtained from a 168 ks Suzaku observation of the Seyfert 1 galaxy Fairall 9. The source is clearly detected out to 30 keV. The observed spectrum is fairly simple; it is well described by a power law with soft excess and disk reflection. A broad iron line is detected, and easily separated from distinct narrow components owing to the resolution of the CCDs in the X-ray Imaging Spectrometer (XIS). The broad line is revealed to be asymmetric, consistent with a disk origin. We fit the XIS and Hard X-ray Detector spectra with relativistically blurred disk reflection models. With the assumption that the inner disk extends to the innermost stable circular orbit, the best-fit model implies a black hole spin parameter of a = 0.60 ± 0.07 and excludes extremal values at a high level of confidence. We discuss this result in the context of Seyfert observations and models of the cosmic distribution of black hole spin.