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Revealing the Location and Structure of the Accretion Disk Wind in PDS 456

Gofford, J.; Reeves, J.N.; Braito, V.; Nardini, E; Costa, M.T.; Matzeu, G.A.; O'Brien, P.; Ward, M.; Turner, T.J.; Miller, L.

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J. Gofford

J.N. Reeves

V. Braito

E Nardini

M.T. Costa

G.A. Matzeu

P. O'Brien

T.J. Turner

L. Miller


We present evidence for the rapid variability of the high-velocity iron K-shell absorption in the nearby (z = 0.184) quasar PDS 456. From a recent long Suzaku observation in 2013 (~1 Ms effective duration), we find that the equivalent width of iron K absorption increases by a factor of ~5 during the observation, increasing from <105 eV within the first 100 ks of the observation, toward a maximum depth of ~500 eV near the end. The implied outflow velocity of ~0.25 c is consistent with that claimed from earlier (2007, 2011) Suzaku observations. The absorption varies on timescales as short as ~1 week. We show that this variability can be equally well attributed to either (1) an increase in column density, plausibly associated with a clumpy time-variable outflow, or (2) the decreasing ionization of a smooth homogeneous outflow which is in photo-ionization equilibrium with the local photon field. The variability allows a direct measure of absorber location, which is constrained to within r = 200-3500 r g of the black hole. Even in the most conservative case, the kinetic power of the outflow is gsim 6% of the Eddington luminosity, with a mass outflow rate in excess of ~40% of the Eddington accretion rate. The wind momentum rate is directly equivalent to the Eddington momentum rate which suggests that the flow may have been accelerated by continuum scattering during an episode of Eddington-limited accretion.


Gofford, J., Reeves, J., Braito, V., Nardini, E., Costa, M., Matzeu, G., …Miller, L. (2014). Revealing the Location and Structure of the Accretion Disk Wind in PDS 456. Astrophysical Journal, 784(1), Article 77.

Journal Article Type Article
Publication Date Mar 20, 2014
Deposit Date May 29, 2014
Publicly Available Date Jun 23, 2014
Journal Astrophysical Journal
Print ISSN 0004-637X
Electronic ISSN 1538-4357
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 784
Issue 1
Article Number 77
Keywords Black hole physics, Quasars: individual (PDS456), X-rays: galaxies.


Published Journal Article (1 Mb)

Copyright Statement
© 2014. The American Astronomical Society. All rights reserved.

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