From Heart Of Darkness
Black hole jets in HD
JUMBO JETCombined X-ray, microwave and visible-light data reveal jets emanating from the central black hole of Centaurus
Astronomers have produced the sharpest images ever of twin jets racing outward from the vicinity of a galaxy's central black hole. Using the combined power of nine radio telescopes arrayed across the Southern Hemisphere, the images reveal features just 15 light-days across in the heart of the nearby galaxy Centaurus A, 12 million light-years away. At its core, the galaxy contains a black hole as massive as 55 million suns. The new images home in on a region around the black hole less than 4.2 light-years across smaller than the distance between the sun and its nearest star, says Roopesh Ojha of NASA's Goddard Space Flight Center in Greenbelt, Md. Ojha and his colleagues describe their findings in the June Astronomy & Astrophysics. To obtain the high-resolution radio images, the team combined data from an array of radio telescopes with resolution equivalent to a single superdish about 80 percent of Earth's diameter. The images reveal for the first time just how close to a black hole a jet can form, a constraint that must now be incorporated into models of how such jets are generated, Ojha says. The jets are thought to arise as matter approaches and falls onto the black hole, fueling the beast and radiating energy in the process. But the exact details are unknown, Ojha notes.
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