Constraining Black Hole Spin with XMM-Newton and Suzaku

Laura Brenneman, ORAU/NASA's GSFC

Relativistically broad iron lines in active galactic nuclei (AGN) provide a powerful diagnostic probe of the inner accretion flow onto supermassive black holes, allowing observers to test the predictions of General Relativity in the strong-field limit. The extent of the broadening seen in the red wing of the Fe-K line, in particular, enables us to place a lower limit on black hole spin in a given source. X-ray instruments with large collecting areas such as XMM-Newton and Suzaku are now allowing us to obtain high-resolution spectra of the Fe-K line region in many AGN. We present black hole spin constraints from a recent XMM survey of nine AGN with broad iron lines and our current spectral fitting of this sample with archival Suzaku data.