Suzaku Observations of Three FeLoBAL QSOs, SDSS J0943+5417, J1352+4239, and J1723+5553

Abstract

We present Suzaku observations of three iron low-ionization broad absorption line quasars (FeLoBALs). We detect J1723+5553 (3\sigma) in the observed 2--10 keV band, and constrain its intrinsic nh column density to nh > 6\times10^{23} \cmsq by modeling its X-ray hardness ratio. We study the broadband spectral index, aox, between the X-ray and UV bands by combining the X-ray measurements and the UV flux extrapolated from 2MASS magnitudes, assuming a range of intrinsic column densities, and then comparing the aox values for the three FeLoBALs with those from a large sample of normal quasars. We find that the FeLoBALs are consistent with the spectral energy distribution (SED) of normal quasars if the intrinsic nh column densities are nh > 7\times10^{23} \cmsq for J0943+5417, nh > 2\times10^{24} \cmsq for J1352+4293, and 6\times10^{23} < \nh < 3\times10^{24} \cmsq for J1723+5553. At these large intrinsic column densities, the optical depth from Thomson scattering can reach \sim6, which will significantly modulate the UV flux. Our results suggest that the X-ray absorbing material is located at a different place from the UV absorbing wind, likely between the X-ray and UV emitting regions. We find a significant kinetic feedback efficiency for FeLoBALs, indicating that the outflows are an important feedback mechanism in quasars.