title: The response of relativistic outflowing gas to the inner accretion disk of a black hole.
abstract: The brightness of an active galactic nucleus is set by the gas falling onto it from the galaxy, and the gas infall rate is regulated by the brightness of the active galactic nucleus; this feedback loop is the process by which supermassive black holes in the centres of galaxies may moderate the growth of their hosts. Gas outflows (in the form of disk winds) release huge quantities of energy into the interstellar medium, potentially clearing the surrounding gas. The most extreme (in terms of speed and energy) of these-the ultrafast outflows-are the subset of X-ray-detected outflows with velocities higher than 10,000 kilometres per second, believed to originate in relativistic (that is, near the speed of light) disk winds a few hundred gravitational radii from the black hole. The absorption features produced by these outflows are variable, but no clear link has been found between the behaviour of the X-ray continuum and the velocity or optical depth of the outflows, owing to the long timescales of quasar variability. Here we report the observation of multiple absorption lines from an extreme ultrafast gas flow in the X-ray spectrum of the active galactic nucleus IRAS 13224-3809, at 0.236 ± 0.006 times the speed of light (71,000 kilometres per second), where the absorption is strongly anti-correlated with the emission of X-rays from the inner regions of the accretion disk. If the gas flow is identified as a genuine outflow then it is in the fastest five per cent of such winds, and its variability is hundreds of times faster than in other variable winds, allowing us to observe in hours what would take months in a quasar. We find X-ray spectral signatures of the wind simultaneously in both low- and high-energy detectors, suggesting a single ionized outflow, linking the low- and high-energy absorption lines. That this disk wind is responding to the emission from the inner accretion disk demonstrates a connection between accretion processes occurring on very different scales: the X-ray emission from within a few gravitational radii of the black hole ionizing the disk wind hundreds of gravitational radii further away as the X-ray flux rises.
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Parker
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Ciro
authors.initials: C
authors.lastname: Pinto
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Fabian
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Lohfink
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Douglas J K
authors.initials: DJ
authors.lastname: Buisson
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: William N
authors.initials: WN
authors.lastname: Alston
authors.affiliation: Department of Astronomy, University of Maryland, College Park, Maryland 20742-2421, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Kara
authors.affiliation: Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, USA.
authors.forename: Edward M
authors.initials: EM
authors.lastname: Cackett
authors.affiliation: Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, USA.
authors.forename: Chia-Ying
authors.initials: CY
authors.lastname: Chiang
authors.affiliation: Remeis Observatory and ECAP, Universitat Erlangen-Nurnberg, Sternwartstrasse 7, 96049 Bamberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dauser
authors.affiliation: Max-Planck-Institut fur extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: De Marco
authors.affiliation: Department of Astronomy and Physics, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia B3H 3C3, Canada.
authors.forename: Luigi C
authors.initials: LC
authors.lastname: Gallo
authors.affiliation: Space Radiation Laboratory, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, California 91125, USA.
authors.forename: Javier
authors.initials: J
authors.lastname: Garcia
authors.affiliation: Space Radiation Laboratory, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, California 91125, USA.
authors.forename: Fiona A
authors.initials: FA
authors.lastname: Harrison
authors.affiliation: Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, California 94305, USA.
authors.forename: Ashley L
authors.initials: AL
authors.lastname: King
authors.affiliation: School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Middleton
authors.affiliation: Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, Michigan 48109, USA.
authors.forename: Jon M
authors.initials: JM
authors.lastname: Miller
authors.affiliation: Centro de Astrobiologia (CSIC-INTA), Departimento de Astrofsica, ESAC, PO Box 78, 28691 Villanueva de la Caada, Madrid, Spain.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Miniutti
authors.affiliation: Department of Astronomy, University of Maryland, College Park, Maryland 20742-2421, USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Reynolds
authors.affiliation: Astronomical Institute Anton Pannekoek, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam, The Netherlands.
authors.forename: Phil
authors.initials: P
authors.lastname: Uttley
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Vasudevan
authors.affiliation: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: Dominic J
authors.initials: DJ
authors.lastname: Walton
authors.affiliation: Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, California 94305, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Wilkins
authors.affiliation: Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, Michigan 48109, USA.
authors.forename: Abderahmen
authors.initials: A
authors.lastname: Zoghbi