You need certain density to start formation progress. Then you get more density as it drags more stuff via gravity from intergalactic void. So new stars form at edges when there is finally enough stuff pulled by gravity of whole galaxy to there for the formation to happen.
It seems that you need quite large concentrations(as in scale of whole universe average) to actually get to star formation. Otherwise stars would be uniform trough the universe.
> You need certain density to start formation progress.
Aren't fluids (such as a hydrogen gas cloud) densest at the bottom of a gravity well? It would be expected that the nearer one is to the galactic center, the denser the intergalactic medium would be.
It seems that you need quite large concentrations(as in scale of whole universe average) to actually get to star formation. Otherwise stars would be uniform trough the universe.
Then again I am not astronomer.