What exactly is a quasar?

[AsherTheThinker94]

I get the general idea of what a quasar is, but what specifically makes a quasar? And what's the importance of it?

 

[MeteorWayne]

In simplest terms, a quasar is a supermassive black hole at the center of a galaxy at dinnertime when the core is exposed to our view. When large amounts of gas or dispupted stars are in the accretion disk surrounding the black hole it gets extremely hot and radiates huge amounts of energy. This was more common shortly after galaxies formed when there was lots to eat. It appears that due to the huge amount of energy released, the area surrounding the black hole is cleaned out by the intense radiation and flow of material away, so they become less common as galaxies age; for example our galaxy's black hole has been pretty quiet recently.

 

[AsherTheThinker94]

Ah, thank you very much, that was perfect

 

[Saiph]

Yep, big black holes eating dinner. Massive powerhouses, and some of the brightest 'objects' in the universe.


Another useful tidbit if you want to look into it on your own: Nearby, less luminous objects called AGN (Active Galactic Nuclei) are 'old quasars'. They're much closer, and so we can sometimes get a lot more detailed info out of observations of them. And yet they are in their fundamental design, the same thing.

 

[SpaceTas]

Quasars were first noted as bright radio sources. When they were photographed they looked like stars, some a little bit fuzzy, and with weird optical spectra. So the name came from quasi (Qu) stellar (sa) radio (r) sources. the ar sound harks to star.

Pulsar has a similar origin pulsating radio star.

 

[chris1996]

A quasar is a black hole in the center of a galaxy that because of the friction created by the gases sliding past each other becomes a very bright celestial body. There are two trails of radiation coming off the poles caused by electrons in the magnetic field around the black hole. Quasars are normally billions of lightyears away, the closest ones being 3 billion lightyears away. We are actually set on a collision course with the Andromeda Galaxy, and when we collide(in 5 or 6 billion years) we might produce a quasar. Quasars are so bright that they outshine nearby stars.We can't see them though.

When a quasars top is set directly at us it is called a blazar.
Streams of energy around the black hole form what is called a DRAGN. I don't remember what the acronym stands for but they actually do look like dragons.

Quasars form when energy and matter gets fed into the black hole in immense quantitys.

Check out The Universe: Pulsars and Quasars on the History Channel to learn more.