Understanding Quasars & Blazars: Definition & Theory

[Xander756]

Hey guys I am a bit new to the astronomy scene and am trying to learn as much as I can about space and the universe. One thing that has confused me is quasars (and then blazars). Exact definitions of these is hard to find online, pages I've found always just start going into radio waves and how we detect them and what not but I don't quite understand what they are even.

Is a quasar just a really dense region in the middle of a galaxy which is powered by a supermassive black hole?

Then one thing I found interesting is that blazars emit large beams but if nothing can escape a black hole why does this happen?

Reading the book "Parallel Worlds" by Michio Kaku he also described a "tunneling" effect of radiation that does escape from black holes and was wondering if someone could explain that a little bit more for me as well.

 

[Radrook]

...
Then one thing I found interesting is that blazars emit large beams but if nothing can escape a black hole why does this happen? ...

..

It happens because the emission is taking place outside of the black hole's event horizon.

 

[Arch2008]

In computer models, a supermassive black hole creates an electromagnetic field like a dynamo. Atoms falling into the event horizon move so fast that their electrons are stripped away and they become charged. A finite amount of material can cross the event horizon at any given time, so any excess material follows electromagnetic lines of force into two opposing charge jets at the magnetic poles. This is the quasar (QUASi-stellAR object) or Active Galactic Nuclei (AGN).

If one of the jets is pointed in the general direction of the Earth, then it is referred to as a blazar. This is because the energized particles of the jets are aimed at our sensors.

At the quantum level, virtual particle pairs are constantly borrowing background energy to pop into existence before colliding, annihilating and returning the energy. However, if two virtual particles are created near a black hole so that one of the particles crosses the event horizon and is lost, then the other virtual particle must gain enough energy from the black hole to become a real particle. This is done through quantum tunneling and the process is known as Hawking Radiation. Over time, black holes can evaporate due to this. This is why any small BH’s created in the Large Hadron Collider would have quickly evaporated.