Dwarf Spheroidals or dark galaxies are those small galaxies that are composed mainly of dark matter.
Such galaxies are usually satellites of other large galaxies like the Milky Way and Andromeda galaxies.
Scientists now believe that these dark galaxies were once gas rich but when they became as satellites of other large galaxies all their visible matter was stripped off them.
Scientists used computer simulations to uncover what might have happened some 10 billion years ago when a gas-dominated dwarf galaxy might have hurtled into the orbit of another giant galaxy. They found that a drag force was created and then the force stripped away all the visible matter of the smaller galaxy.
Astronomers from the Stanford University have stated that:
“This is one step toward a more complete understanding of the formation of structure in the Universe, which is one of the fundamental goals of astrophysics.”
Via: BBC
