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arXiv · 1801.08899

A new relativistic component of the accretion disk wind in PDS 456

James Reeves·Valentina Braito·Emanuele Nardini·Andrew Lobban·Gabriele Matzeu·Michele Costa
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Abstract

Past X-ray observations of the nearby luminous quasar PDS 456 (at $z=0.184$) have revealed a wide angle accretion disk wind (Nardini et al. 2015), with an outflow velocity of $\sim-0.25c$. Here we unveil a new, relativistic component of the wind through hard X-ray observations with NuSTAR and XMM-Newton, obtained in March 2017 when the quasar was in a low flux state. This very fast wind component, with an outflow velocity of $-0.46\pm0.02c$, is detected in the iron K band, in addition to the $-0.25c$ wind zone. The relativistic component may arise from the innermost disk wind, launched from close to the black hole at radius of $\sim10$ gravitational radii. The opacity of the fast wind also increases during a possible obscuration event lasting for 50 ks. We suggest that the very fast wind may only be apparent during the lowest X-ray flux states of PDS 456, becoming overly ionized as the luminosity increases. Overall, the total wind power may even approach the Eddington value.

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James Reeves, Valentina Braito, Emanuele Nardini, Andrew Lobban, Gabriele Matzeu, Michele Costa. 2018-01-26. A new relativistic component of the accretion disk wind in PDS 456. https://doi.org/10.3847/2041-8213/aaaae1

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