* They're not uniformly hot: A quasar is a supermassive black hole actively feeding on surrounding gas and dust. The accretion disk around the black hole is where the heat originates, and it's incredibly hot – estimated to be billions of degrees Kelvin. However, this extreme heat is localized within the accretion disk.
* Different emissions: Quasars emit a wide spectrum of radiation, from radio waves to gamma rays. Each type of radiation has a different temperature associated with it.
* Difficult to measure: Directly measuring the temperature of a quasar's accretion disk is extremely challenging due to its vast distance and the intense radiation it emits.
Comparisons to other celestial objects:
* Stars: Even the hottest stars, like blue supergiants, have surface temperatures of around 50,000 K. This is dwarfed by the billions of degrees Kelvin found in a quasar's accretion disk.
* Neutron stars: Neutron stars are incredibly dense objects with surface temperatures reaching millions of degrees Kelvin, but this is still significantly cooler than a quasar's accretion disk.
* Supernovae: Supernova explosions release immense amounts of energy and have extremely high temperatures, potentially reaching billions of degrees Kelvin. However, these temperatures are localized and short-lived compared to the sustained heat of a quasar's accretion disk.
In essence, quasars are among the hottest objects known in the universe, with temperatures exceeding those of stars, neutron stars, and even supernovae. But the heat is concentrated within the accretion disk and varies significantly depending on the type of radiation being emitted.
