2 ms·

Quasars are bright because they are surrounded by material that accretes and shines. If they are isolated then they are just quiet black holes.

• pbhjpbhj 2y ago
  Well, the accretion disk surely runs out at some point, and just before that point, shouldn't it look like a quasar in surprisingly empty space?
  • saagarjha 2y ago
    The brightness comes from the accretion disk.
    • pbhjpbhj 2y ago
      Yes, I understand that, but what is the failure mode - is it gradual or rapid? If it is rapid, then the system keeps shining even when it appears almost empty. If gradual, then I probably need to revisit what I learned of quasars done decades ago...
      • saagarjha 2y ago
        Let me know what you find ;)