Some dwarf galaxies in the early universe travelled so fast that their gas was stripped from them, according to a new computer simulation.
This cosmic vanishing act could help explain a long-standing mystery: astronomers observe fewer dwarf galaxies in the "Local Group" — the collection of galaxies near the Milky Way — than what models of the universe's formation predict.
But if these galaxies are losing gas, that could explain why they don't appear as plentiful as they should.
Because these dwarf galaxies were so small when they formed, they don't have large reserves of gas to begin with. Stripping any gas away would leave these galaxies so small and dim that they would be all but invisible from Earth. [Stunning Photos of Our Milky Way Galaxy]
"This is something that came out of the simulations, and had not been anticipated, and had not been seen before. It was an interesting discovery," said Julio Navarro, a University of Victoria astronomer and co-author of a paper describing the discovery.
The study, published in the Feb. 1 issue of Astrophysical Journal Letters, was led by graduate studentAlejandro Benitez-Llambay from the University of Cordoba in Argentina. You can also watch a SPACE.com video explaining the missing dwarf galaxies.
source -- http://www.space.com/20280-vanishing-dwarf-galaxies-mystery.html