Galactic Building Blocks

The current view of galactic formation is that galaxies form from a "bottom-up" method.

In this picture, small dwarf galaxies, full of metal poor stars, were attracted by dark matter halos in the early universe which merged into larger galaxies. Many of those metal poor stars can still be seen today in the halo of the galaxy, but it was thought that the building blocks from which the galaxies were constructed were long gone or had evolved on their own and would no longer resemble the primord [...]

Full story at http://spacefellowship.com/news/art17479/galactic-building-blocks.html