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Magnetic Fields Help Black Holes Pull In Matter

Even though the gravity from black holes is so strong that light can’t even escape, we can see the radiation from the superheated matter that’s about to be consumed. Until now, scientists haven’t been able to explain how all this matter continuously falls into the black hole – it should just orbit, like planets going around a star. New data from the Chandra X-Ray Observatory shows that a black hole’s powerful magnetic field creates a turbulence in surrounding matter that helps drive it inward to be consumed.

Black holes are lighting up the Universe, and now astronomers may finally know how. New data from NASA’s Chandra X-ray Observatory show for the first time that powerful magnetic fields are the key to these brilliant and startling light shows.

It is estimated that up to a quarter of the total radiation in the Universe emitted since the Big Bang comes from material falling towards supermassive black holes, including those powering quasars, the brightest known objects. For decades, scientists have struggled to understand how black holes, the darkest objects in the Universe, can be responsible for such prodigious amounts of radiation.


“By intergalactic standards J1655 is in our backyard, so we can use it as a scale model to understand how all black holes work, including the monsters found in quasars,” said Jon M. Miller of the University of Michigan, Ann Arbor, whose paper on these results appears in this week’s issue of Nature.


Scientists have long thought that magnetic turbulence could generate friction in a gaseous disk and drive a wind from the disk that carries angular momentum outward allowing the gas to fall inward.

Using Chandra, Miller and his team provided crucial evidence for the role of magnetic forces in the black hole accretion process. The X-ray spectrum, the number of X-rays at different energies, showed that the speed and density of the wind from J1655’s disk corresponded to computer simulation predictions for magnetically-driven winds. The spectral fingerprint also ruled out the two other major competing theories to winds driven by magnetic fields.

“In 1973, theorists came up with the idea that magnetic fields could drive the generation of light by gas falling onto black holes,” said co-author John Raymond of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “Now, over 30 years later, we finally may have convincing evidence.”


“Just as a doctor wants to understand the causes of an illness and not merely the symptoms, astronomers try to understand what causes phenomena they see in the Universe,” said co-author Danny Steeghs also of the Harvard-Smithsonian Center for Astrophysics. “By understanding what makes material release energy as it falls onto black holes, we may also learn how matter falls onto other important objects.”



Additional information and images can be found at:
http://chandra.harvard.edu and http://chandra.nasa.gov

Original Source: Chandra News Release



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