Hottest Place in the Universe

A quasar, which stands for “quasi-stellar radio source,” is an extremely luminous astronomical object found at the center of some distant galaxies. They are among the most brilliant and energetic objects in the universe. Here are some key points about quasars:

1. Supermassive Black Holes: At the heart of a quasar is a supermassive black hole, often with a mass ranging from millions to billions of times that of the Sun.
2. Accretion Disk: Surrounding the black hole is an accretion disk, which is a rotating disk of gas and dust. As material from this disk spirals into the black hole, it heats up to extremely high temperatures, emitting vast amounts of light and radiation. As material from the disk falls inwards, 3C 273 fires off super fast jets into the surrounding space. In the photograph above, you can see this as a cloudy streak on the top left of the image, measuring roughly 200,000 light years in length.
3. Immense Brightness: Quasars are so bright that they can outshine their entire host galaxy. Their luminosity makes them visible across great distances, even billions of light-years away.
4. Emission of Energy: They emit energy across the electromagnetic spectrum, including radio waves, visible light, ultraviolet light, X-rays, and gamma rays.
5. High Redshifts: Many quasars have high redshifts, which means they are moving away from Earth at a significant fraction of the speed of light. This high redshift also indicates that we see them as they were in the distant past, often billions of years ago.
6. Role in Galaxy Formation: Quasars are thought to play a key role in the formation and evolution of galaxies.
7. Active Galactic Nuclei (AGN): Quasars are a type of Active Galactic Nucleus (AGN), which is a general term for any galaxy’s central region that shows signs of energetic processes beyond those expected from stars and their evolution alone.

Quasars provide important clues to the conditions in the early universe and are crucial in the study of cosmology and galaxy evolution.