Evidence for a radiatively driven disc-wind in PDS 456?
Tombesi, F.; Reeves, J. N.; Braito, V.; Nardini, E.; Matzeu, G. A.; Costa, M. T.; McLaughlin, D. E.; Lobban, A. P.
Italy, United Kingdom, United States
Abstract
We present a newly discovered correlation between the wind outflow velocity and the X-ray luminosity in the luminous (Lbol ∼ 1047erg s - 1) nearby (z = 0.184) quasar PDS 456. All the contemporary XMM-Newton, NuSTAR and Suzaku observations from 2001-2014 were revisited and we find that the centroid energy of the blueshifted Fe K absorption profile increases with luminosity. This translates into a correlation between the wind outflow velocity and the hard X-ray luminosity (between 7 and 30 keV) where we find that v_w/c∝ L_{7-30}^{γ } where γ = 0.22 ± 0.04. We also show that this is consistent with a wind that is predominately radiatively driven, possibly resulting from the high Eddington ratio of PDS 456.