![](https://www.epfl.ch/research/facilities/scitas/wp-content/uploads/2018/02/Image_Astrophysics-300x169.png)
This picture shows the early stage of the build up of a simulated very small galaxy, about 200 mega years after the Big Bang. The blue-grey colours trace the gas while the yellow one corresponds to the stars.
The numerous visible bubbles result from the explosions of the first dying stars.