Difference between quasar and Active Galactic Nuclei?
Are there any differences between quasars and Active Galactic Nuclei (AGN)? As I understand it, they are both caused by extremely luminous electromagnetic emission from material accreting onto a super-massive black hole. If they have the same source, is there still some fundamental difference between them (and if so what is it) or are they two names for the same thing?
A quasar is a type of AGN. Its main property is that it's galaxy axis points towards the earth and this way we receive its light and radio signals. That's why they are one of the most energetic AGN. Here you can see a relation of all the AGN types: http://en.wikipedia.org/wiki/Active_galactic_nucleus#Summary
An AGN where the jet axis points towards the Earth is known as a "Blazar" or a BL Lac object. There is no suggestion that the extreme luminosity of more than a small percentage of quasars is caused by beaming.
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Content dated before 7/24/2021 11:53 AM
HDE 226868 8 years ago
Quasars are sometimes considered a class of AGNs.