Relativistic Components of the Ultra-fast Outflow in the Quasar PDS 456 from Chandra/HETGS, NuSTAR, and XMM-Newton Observations

We present the spectral analysis of Chandra/High Energy Transmission Grating Spectrometer (HETGS) and NuSTAR observations of the quasar PDS 456 from 2015, and XMM-Newton and NuSTAR archival data from 2013 to 2014, together with Chandra/HETGS data from 2003. We analyzed these three different epochs in a consistent way, looking for absorption features corresponding to highly ionized blueshifted absorption lines from H-like and He-like ions of iron (and nickel), as well as of other elements (O, Ne, Si, and S) in the soft band. We confirm the presence of a persistent ultra-fast outflow (UFO) with a velocity of v _out = -0.24 to -0.29 c, that has previously been detected. We also report the detection of an additional faster component of the UFO with a relativistic velocity of v _out = -0.48 c. We implemented photoionization modeling, using XSTAR analytic model warmabs, to characterize the physical properties of the different kinematic components of the UFO and of the partially covering absorber detected in PDS 456. These two relativistic components of the UFO observed in the three epochs analyzed in this paper are powerful enough to impact the host galaxy of PDS 456 through feedback from active galactic nuclei.