For a long time, astronomers had no explanation for the deep space phenomenon they called a quasar. Discovered after the advent of radio telescopes in the 50s, these objects were a complete mystery. All scientists knew is that somewhere out in deep space some sort of thing that could be as big as a solar system was emitting an enormous amount of energy. They also had very strange spectral lines, were extremely power dense, and were smaller than our solar system. Scientists called them quasi-stellar objects, but soon they came to be known as quasars. The current theory for these objects is that they are supermassive black holes. Here’s more from Astronomy Now:
Quasars are extremely active supermassive black holes emitting torrents of energy as they consume surrounding gas and dust. Finding a double quasar just 3 billion years after the Big Bang may shed light on how galaxies came together in the early universe to form ever larger structures. Not to mention how supermassive black holes grow through mergers.
“We don’t see a lot of double quasars at this early time in the universe. And that’s why this discovery is so exciting,” said graduate student Yu-Ching Chen of the University of Illinois at Urbana-Champaign, lead author of a study published in the journal Nature.
“Knowing about the progenitor population of black holes will eventually tell us about the emergence of supermassive black holes in the early universe, and how frequent those mergers could be,” he added.