Dust buster eyes fireworks in nearby galaxy.Ten million light-years from Earth lies the nearest galaxy with a heart of fire. Powered by a central black hole that sucks in stars and gas, the giant, radio-emitting galaxy Centaurus A Centaurus A (also known as NGC 5128) is a lenticular galaxy about 14 million light-years away in the constellation Centaurus. It is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers got a further jolt several hundred million years ago when it swallowed a disk-shaped galaxy. With such an example of cosmic violence close to home, astronomers should have a field day studying black holes and galactic mergers. However, a stripe of dust girdling Girdling, also called ring barking or ring-barking, is the process of completely removing a strip of bark (consisting of Secondary Phloem tissue, cork cambium, and cork) around a tree's outer circumference, causing its death. the galaxy has clouded efforts to observe the maelstrom Maelstrom, whirlpool, Norway: see Moskenstraumen. . Partially penetrating the dust with a near-infrared camera, the Hubble Space Telescope Hubble Space Telescope (HST), the first large optical orbiting observatory. Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble) was expected to provide the clearest view yet obtained of the universe. has now recorded the first detailed portrait of the galaxy's nucleus. Images unveiled this week show that a disk of gas extending 130 light-years in diameter and coming within 7 light-years of the center encircles the black hole. Curiously, the disk is tilted with respect to the black hole's axis, like a loose wheel around an axle. The axis is defined by a jet shooting from the core. The newly found disk may be linked to an unseen, inner disk of gas that is aligned with the axis and fuels the black hole, notes study collaborator Ethan J. Schreier of the Space Telescope Science Institute The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST; in orbit since 1990) and for the James Webb Space Telescope (JWST; scheduled to be launched in 2013). in Baltimore. He and his colleagues presented the images May 14 at a briefing in Washington, D.C. They describe their study in the June 1 Astrophysical Journal Letters. If there are disks aligned in different directions, "it may mean that the gravitational grav·i·ta·tion n. 1. Physics a. The natural phenomenon of attraction between physical objects with mass or energy. b. The act or process of moving under the influence of this attraction. 2. pull of the ... galaxy is stronger than the gravitational pull of the black hole," says Schreier. If that's the case, the black hole, estimated to weigh as much as I billion suns, may have slightly less mass than predicted. An analysis of images taken by the Infrared Space Observatory Infrared Space Observatory: see infrared astronomy. Infrared Space Observatory (ISO) European Space Agency satellite that from 1995 to 1998 observed astronomical sources of infrared radiation. The satellite, which carried a 60-cm (24-in. may bolster that interpretation. Although the observatory, which ended its mission in April, had a lower-resolution telescope than Hubble, it recorded emissions at longer infrared wavelengths, which penetrate dust more easily. The images indicate that most of the radiation comes from the birth of stars rather than from material spiraling into the galaxy's black hole, notes I. Felix Mirabel of the Centre D'Etudes de Saclay in Gif-sur-Yvette, France. |
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