ScienceDaily (Oct. 12, 2010) — Galaxies like our own Milky Way formed easily and have also been the largest spiral galaxies in the universe for almost 4 billion years.
This is shown in a new study by associate professor Kambiz Fathi of the Department of Astronomy at Stockholm University. The study is now published in the scientific journal The Astrophysical Journal Letters.
Astronomers believe that galaxies are formed by a complex interplay between the processes that affect not only the stars and gas but also to supermassive black holes and possibly also the mysterious dark matter that surrounds every galaxy and whose nature remains unexplained.
"Galaxy formation history may be telling us something about the places in the universe where life can form," says Kambiz Fathi. Large galaxies like the Milky Way swim in a sea of many smaller galaxies, and in this process assimilate the small galaxies, sort of in the same fashion as "mergers and acquisitions" in the financial world.
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http://www.sciencedaily.com/releases/2010/10/101011090227.htm