Suzaku wide-band observations of black-hole binaries and AGNs: Continuum and Fe-K lines

Suzaku has enabled us to study wide-band spectral and timing properties of black-hole binaries and AGNs more accurately than ever, and revealed how the continuum definition can affect Fe-Kline profiles. We have reproduced 0.5-300 keV spectra of Cyg X-1 and GRO J1655-40 in terms of thermal Comptonization in highly inhomogeneous coronae. In both objects, R_in was constrained by the Fe-K line profile and soft excess as ∼10 R_g, as opposed to the relativistic Fe-K line reported in the literature. We also re-analyzed the 0.7-300 keV Suzaku spectra of GX 339-4, and found that a careful modeling of the continuum leads to R_in>R_g(Yamada et al. 2009), again in disagreement with Miller et al. (2008). Furthermore, through a systematic analysis of AGNs, we discovered a hard spectral component in the HXD-PIN band, which varies independently of the powerlaw. Taking this into account, the time-averaged spectra of MCG-6-30-15 have been explained by invoking neither a large refection fraction, nor an extreme broad Fe-K line. The essence here is that the hard X-ray (20-40 keV) bump may be partially explained as an additional Comptonization component. Our results indicate that the extremely relativistic Fe-K line reported for some objects is not a unique solution, and depends in many cases on the continuum modeling.