New Image Shows Galactic Serial Killer
New Image Shows Galactic Serial Killer
April 2, 2014
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Image Credit: This new image from the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile shows a
contrasting pair of galaxies: NGC 1316, and its smaller companion NGC 1317 (right). Although NGC 1317 seems to have
had a peaceful existence, its larger neighbour bears the scars of earlier mergers with other galaxies. Credit: ESO
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This new image from the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile shows two contrasting galaxies: NGC 1316, and its smaller neighbor NGC 1317. These two are quite close to each other in space, but they have very different histories. The small spiral NGC 1317 has led an uneventful life, but NGC 1316 has engulfed several other galaxies in its violent history and shows the battle scars.
Several clues in the structure of NGC 1316 reveal that its past was turbulent. For instance, it has some unusual dust lanes embedded within a much larger envelope of stars, and a population of unusually small globular star clusters. These suggest that it may have already swallowed a dust-rich spiral galaxy about three billion years ago.
Also seen around the galaxy are very faint tidal tails — wisps and shells of stars that have been torn from their original locations and flung into intergalactic space. These features are produced by complex gravitational effects on the orbits of stars when another galaxy comes too close. All of these signs point to a violent past during which NGC 1316 annexed other galaxies and suggest that the disruptive behavior is continuing.
NGC 1316 is located about 60 million light-years away from Earth in the southern constellation of Fornax (The Furnace). It also bears the name Fornax A, reflecting the fact that it is the brightest source of radio emission in the constellation — and in fact the fourth brightest radio source in the entire sky. This radio emission is driven by material falling into the supermassive black hole at the center of the galaxy and has probably been provided with extra fuel by the interactions with other galaxies.
More:
http://www.redorbit.com/news/space/1113111302/galactic-serial-killer-040214/#4uOtbiRjqBgzCmuv.99