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News Release 707 of 1044

October 27, 1999 02:00 PM (EDT)

News Release Number: STScI-1999-43

Very Long Baseline Array Reveals Formation Region of Giant Cosmic Jet Near a Black Hole

October 27, 1999: Astronomers have seen the exhaust products of black hole "engines": narrow beams of material traveling at nearly the speed of light. But they could only speculate where and how those beams were created. Now astronomers have gained their first glimpse at the mysterious region near a black hole at the heart of a distant galaxy where those columns of material are formed. Images of this phenomenon, taken by radio telescopes in Europe and the U.S., are the most detailed ever of the center of the galaxy M87, some 50 million light-years from Earth.

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Q & A: Understanding the Discovery

  1. 1. What causes the beams?

  2. Material at the center of M87 is drawn inward by the black hole's strong gravitational grip. This material forms a rapidly spinning flat disk, called an accretion disk. Astronomers believe that some material escapes along the poles of this disk, forming a wide jet. Magnetic fields in the disk may pinch the jet into narrow beams. Black holes are compact, dense powerhouses at the core of galaxies.

  3. 2. What does this finding mean?

  4. Astronomers always had speculated that the jet had to be made by some mechanism relatively near the black hole, but as they looked closer to the center, they kept seeing an already-formed beam. Now astronomers have shown that M87's jet is formed within a few tenths of a light-year of the galaxy's core, presumed to be a black hole three billion times more massive than the Sun. This new information will help scientists decipher how these powerful "engines" work.

    These three images - two by radio telescopes, one by the Hubble telescope — pinpoint the region close to the black hole where the narrow jets of material are formed.

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Credit: NASA, National Radio Astronomy Observatory/National Science Foundation, and John Biretta (STScI/JHU)