ESA | Science & Technology | XMM-Newton | 2016 July 12
Black Hole Makes Material Wobble Around It
NASA | JPL-Caltech | NuSTAR | 2016 July 12
[img3="This artist's impression depicts the accretion disc surrounding a black hole, in which the inner region of the disc precesses. (Credit: ESA/ATG medialab)"]http://photojournal.jpl.nasa.gov/figure ... 7_fig1.jpg[/img3][hr][/hr]The European Space Agency's orbiting X-ray observatory, XMM-Newton, has proved the existence of a "gravitational vortex" around a black hole. The discovery, aided by NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission, solves a mystery that has eluded astronomers for more than 30 years, and will allow them to map the behavior of matter very close to black holes. It could also open the door to future investigations of Albert Einstein's general relativity.
Matter falling into a black hole heats up as it plunges to its doom. Before it passes into the black hole and is lost from view forever, it can reach millions of degrees. At that temperature it shines X-rays into space.
In the 1980s, pioneering astronomers using early X-ray telescopes discovered that the X-rays coming from stellar-mass black holes in our galaxy flicker. The changes follow a set pattern. When the flickering begins, the dimming and re-brightening can take 10 seconds to complete. As the days, weeks and then months progress, the period shortens until the oscillation takes place 10 times every second. Then, the flickering suddenly stops altogether.
The phenomenon was dubbed the Quasi Periodic Oscillation (QPO). ... During the 1990s, astronomers had begun to suspect that the QPOs were associated with a gravitational effect predicted by Einstein's general relativity: that a spinning object will create a kind of gravitational vortex. ...
A quasi-periodic modulation of the iron line centroid energy in the black hole binary H 1743-322 - Adam Ingram et al
- Monthly Notices of the RAS 461(2):1967 (2016 Sep 11) DOI: 10.1093/mnras/stw1245
arXiv.org > astro-ph > arXiv:1607.02866 > 11 Jul 2016