Sleeping monster from the early days of the universe

At first glance, XMM-2599 appears to be a rather boring galaxy (because it’s dying). But an international research team has recently discovered that it’s really a sleeping monster. XMM-2599 formed more than 12 billion years ago, when the universe was still very young, only 1.8 billion years old. At first the galaxy was extremely active. “Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultramassive galaxy,” says...