The response of relativistic outflowing gas to the inner accretion disk of a black hole

• Published in: Nature (London) 2017-03, Vol.543 (7643), p.83-86
• Main Authors: Parker, Michael L., Pinto, Ciro, Fabian, Andrew C., Lohfink, Anne, Buisson, Douglas J. K., Alston, William N., Kara, Erin, Cackett, Edward M., Chiang, Chia-Ying, Dauser, Thomas, De Marco, Barbara, Gallo, Luigi C., Garcia, Javier, Harrison, Fiona A., King, Ashley L., Middleton, Matthew J., Miller, Jon M., Miniutti, Giovanni, Reynolds, Christopher S., Uttley, Phil, Vasudevan, Ranjan, Walton, Dominic J., Wilkins, Daniel R., Zoghbi, Abderahmen
• Format: Article
• Language: English
• Subjects: 639/33/34/863; 639/33/34/864; Absorption; Accretion; Accretion disks; Black holes; Black holes (Astronomy); Emissions; Humanities and Social Sciences; letter; multidisciplinary; Observations; Optical analysis; Relativism; Science; Spectrum analysis; Velocity; Wind
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature21385

X-ray detection of an ultrafast outflow of gas is strongly linked with energy emission from the inner accretion disk of a black hole, suggesting that X-rays ionize the outflowing disk wind. Gas outflow responds to a black hole's inner disk (Parker 21385, Physics Letter, Leslie Sage) Supermassive black holes in the centres of galaxies may moderate the growth of their hosts by a feedback loop involving the brightness of the active galactic nucleus and the amount of gas falling into it from the galaxy. Gas outflows release huge quantities of energy into the interstellar medium, potentially clearing the surrounding gas. Michael Parker et al . report the observation of multiple absorption lines from an ultrafast gas flow in the X-ray spectrum of the active galactic nucleus IRAS 13224 3809, where the absorption is strongly anti-correlated with the emission from the inner regions of the accretion disk. Signatures of the wind are consistent with a single ionized outflow, linking the two phenomena. The detection of the wind responding to the emission from the inner disk demonstrates a connection between accretion processes occurring on very different scales, with the X-rays from within a few gravitational radii of the black hole ionizing the fast outflowing gas as the X-ray flux rises. 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 1 . Gas outflows (in the form of disk winds) release huge quantities of energy into the interstellar medium 2 , 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 3 . The absorption features produced by these outflows are variable 4 , 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 13224−3