Quasars are the brightest objects in the universe and among the most energetic. They outshine entire galaxies of billions of stars. A supermassive black hole lies at the heart of every quasar, but not every black hole is a quasar. Only the black holes that are feeding most voraciously can power a quasar. Material falling into the supermassive black hole heats up, and causes a quasar to fiercely shine across the universe like a lighthouse beacon.
![](https://scx1.b-cdn.net/csz/news/tmb/2020/8-simulationss.jpg)
Source:
https://phys.org/news/2020-10-simulations-webb-telescope-reveal-distant.html