Most people think of the giant galaxies as islands of stars, gas and dust that block our universe with its light. Theory, however, predicts that there are other types of galaxies, devoid of stars, and consisting mainly of dense gas. These "dark" galaxies you can not see on the black background of the universe.
Now an international team of astronomers has found a few bright galaxies, watching the glow of hydrogen these galaxies, UV-induced nearby quasar HE0109-3518.
The study of dark galaxies may help scientists better understand the evolution of, for example, our Milky Way galaxy. Researchers believe that the predecessor of the Milky Way was a small bright galaxy that merged with the nearby dark galaxies serve her sources of gas for the formation of a large number of stars.
Observations of galaxies were made using very large telescope in Chile, and the Digital Sky Survey 2.