The Many Faces of Monster Galaxies

The earliest galaxies in the universe earned the nickname “monster galaxies” for good reason, they formed stars at rates hundreds of times faster than the Milky Way, growing rapidly after the dawn of time. Astronomers using ALMA and the James Webb Space Telescope have now revealed that three such monsters each achieved their extraordinary growth through completely different mechanisms. By comparing where stars are forming today with where they formed in the past, researchers discovered that galaxy collisions, internal instability, and minor mergers can all trigger these growth spurts, fundamentally changing our understanding of how the universe’s most massive galaxies came to be.