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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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Rubble of a Galactic Smashup
8 September 1997 7:30 pm
Astronomers have discovered a lonely arc of debris that may be a remnant of a high-speed galactic collision. The arc of stars and gas, which seems unattached to any galaxy, is the first of its kind to be found by astronomers but conforms to theoretical explanations of what happens when two large galaxies collide. The work is described in a paper submitted to the Monthly Notices of the Royal Astronomical Society.
Many galaxies have long "tails" of gas and stars, usually stretched out by friction from slow mergers with other galaxies. But galaxies whirling around in clusters move faster than 1000 kilometers per second--much too quick for a gentle merger. However, a violent encounter could leave something akin to the faint arc, some 260,000 light-years long, spotted by Neil Trentham of the Institute of Astronomy in Cambridge and Bahram Mobasher of Imperial College in London while searching the Coma Cluster with the University of Hawaii's 2.2-meter telescope on Mauna Kea. Says Trentham, "When two big galaxies bang together at high speeds, you should get these huge arcs of debris shooting out."
The finding is welcome news to Neil Katz, an astronomer at the University of Massachusetts, Amherst, who has modeled such high-speed galaxy encounters. "Our simulations predicted there should be a lot of debris in clusters," but previous observations were too short to pick up the faint arc.