in the constellation Leo
260 million light-years
Unknown 0 times the mass of the Sun
The likely supermassive black hole at the core of NGC 3862 is doing a bad job of hiding. Although astronomers have not yet measured the black hole's mass or its gravitational influence on the stars around it, they know the black hole is there because it produces a powerful "jet" of energy -- one of the most powerful yet detected from any black hole.
Jets probably form in the inner regions of a black hole's accretion disk, which consists of superhot plasma (a state of matter in which the electrons in atoms are stripped away from the atoms' nuclei) that is spiraling toward the black hole. The disk spins so fast that it generates a powerful magnetic field. At the inner edge of the disk, the magnetic field funnels some of the particles back into space at a right angle to the disk itself. As the particles spiral off into space, they emit radio waves.
This mechanism actually produces two jets -- one from each of the black hole's poles. In many cases, though, only one jet is easily visible, either because it aims more directly at Earth, or because the other is obscured by gas and dust.
That's the case with NGC 3862. Astronomers have measured one jet from the galaxy's core, on the side of the core that faces Earth. There are hints of a second jet on the opposite side of the core, but no definitive detection.
The single jet is not only one of the most powerful yet discovered, it's also one of the most intensely studied. It forms a narrow beam for hundreds of light-years, then it begins to spread out like a cone. At distances of almost 1,000 light-years, it begins to form clumps, perhaps because it runs into a ring of dust around the galaxy's center.
Continued observations of the jet, combined with other studies of NGC 3862, should eventually produce a more complete dossier on the galaxy's supermassive black hole.
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This document was last modified: January 20, 2011.