We report on XMM-Newton spectroscopic observations of the luminous , radio-quiet quasar PDS 456 .
The hard X-ray spectrum of PDS 456 shows a deep absorption trough ( constituting 50 % of the continuum ) at energies above 7 keV in the quasar rest frame , which can be attributed to a series of blue-shifted K-shell absorption edges due to highly ionized iron .
The higher resolution soft X-ray RGS spectrum exhibits a broad absorption line feature near 1 keV , which can be modeled by a blend of L-shell transitions from highly ionized iron ( Fe xvii – xxiv ) .
An extreme outflow velocity of \sim 50000 km s ^ { -1 } is required to model the K and L shell iron absorption present in the XMM-Newton data .
Overall , a large column density ( N _ { H } = 5 \times 10 ^ { 23 } cm ^ { -2 } ) of highly ionized gas ( log \xi = 2.5 ) is required in PDS 456 .
A high mass outflow rate of \sim 10 ~ { } M _ { \odot } year ^ { -1 } ( assuming a conservative outflow covering factor of 0.1 steradian ) is derived , which is of the same order as the overall mass accretion rate in PDS 456 .
The kinetic energy of the outflow represents a substantial fraction ( \sim 10 % ) of the quasar energy budget , whilst the large column and outflow velocity place PDS 456 towards the extreme end of the broad absorption line quasar population .