Galaxies, like spiral and barred spiral galaxies, have regions where stars are born from clouds of hydrogen gas.
Early galaxies had a lot of this star-forming gas, but they could have used it up quickly, creating lots of stars and then dying out.
However, galaxies seem to have a way of regulating their star formation by using supermassive black holes at their centers.
These black holes act like hearts, pulsing and releasing energy that slows down the rate at which gas is used up for star formation, giving galaxies a longer lifespan.
