Universe's early galaxies grew massive through collisions

It has long puzzled scientists that there were enormously massive galaxies that were already old and no longer forming new stars in the very early universe, approximately 3 billion years after the Big Bang. Now new research shows that these massive galaxies were formed by explosive star formation that was set in motion by the collision of galaxies a few billion years after the Big Bang.

Fuente : http://feeds.sciencedaily.com/~r/sciencedaily/~3/b...