Recently, astronomers used several powerful telescopes to look into the past and observe some galaxies from a time when the Universe was very young. (To learn about how astronomers can look at galaxies from the past, click here.) 

Some of these galaxies are especially interesting to astronomers and they have been highlighted in red in this new space picture. When the Universe was very young, the galaxies that have been highlighted were in a star-making frenzy, which is called a starburst. These starbursts didn’t last long and this is what astronomers are interested in: What put a stop to this rapid star production?

Astronomers now have a possible explanation. The idea is that, while starburst galaxies worked quickly, they also created a lot of mess as they made new stars. This mess was then gobbled up by ‘space monsters’ that are found at the centre of galaxies, which are called super-massive black holes. And feeding these monsters released powerful jets of energy that blew away or destroyed the ingredients that the galaxies needed to create more stars. So, no more starbursts!

“In short, the galaxies’ glory days of intense star formation also doom them by feeding the giant black hole at their centre,” says astronomer David Alexander.