Hubble Spots Mysterious Dark Matter ‘Core’
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This composite image shows the distribution of dark matter, galaxies, and hot gas in merging galaxy cluster Abell 520.
Image Credit: NASA, ESA, CFHT, CXO, Jee, and Mahdavi
Astronomers are left scratching their heads over a new observation of a “clump” of dark matter apparently left behind after a massive merger between galaxy clusters.
What is so puzzling about the discovery is that the dark matter collected into a “dark core” which held far fewer galaxies than expected. The implications of this discovery present challenges to current understandings of how dark matter influences galaxies and galaxy clusters.
Initially, the observations made in 2007 were dismissed as bad data. New data obtained by the Hubble Space Telescope in 2008 confirmed the previous observations of dark matter and galaxies parting ways.
The new evidence is based on observations of a distant merging galaxy cluster named Abell 520. At this point, astronomers have a challenge ahead of them in order to explain why dark matter isn’t behaving as expected.
Read the full article over at Universe Today
Ray Sanders is a Sci-Fi geek, astronomer and blogger. Currently researching variable stars at Arizona State University, he writes for Universe Today, The Planetary Society blog, and his own blog, Dear Astronomer
2012-12-04 08:07:24
Source: http://www.dearastronomer.com/2012/03/02/hubble-spots-mysterious-dark-matter-core/
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