The Theory of Nothing

What the heck is a quasar?

What the heck is a quasar?

Quasar is a contraction for quasi-stellar radio source. It's always associated with a super massive black hole in the center of a galaxy, and in particular the center of new spiral galaxies. Imagine a spiral galaxy like our Milky Way, and then imagine two enormously long bright beams of energy shooting out of a super massive black hole from opposite sides. They look like two blow torches shooting out of the top and bottom of the galaxy, and they are one of the most spectacular objects in the universe.
Why do quasars form? The answer is believed to be the effect of an accretion disc of gas and dust spinning around the event horizon of a super massive black hole, which is believed to be at the center of most all galaxies, including ours. The beams or jets shoot out often faster than light and extend for millions of light years, and they are extremely luminous and emit lots of visible, UV, X-ray and radio signal energy. They are often a hundred times brighter than the Milky Way galaxy and four trillion times brighter than our sun. A typical quasar creates a luminosity of ten to the forty watts, which translates to the super massive black hole causing the quasar having to consume 600 Earths per minute (according to Wikipedia).
Basically, a quasar happens because the black hole sucks in dust and debris, including entire stars, from the accretion disc orbiting its event horizon so quickly it gets indigestion and spits out what it can't swallow. The rotation of the accretion disc is so fast that the energy imparted to the quasar jets is enormous, and these jets often shoot out at almost the speed of light (they call this relativistic because of Einstein's theories).
A galaxy that has a quasar is considered an active galaxy. In fact, most of the quasars seen in the universe exhibit red shifts. This means that they are moving away from us at high velocities. The faster something like a galaxy moves away from us the more its spectrum is shifted to the red. That's what red shift means and it's a measure of how far away these active galaxies are. And, that's a good thing because the radiation emitted from a quasar is very dangerous to life.
The reality is that quasars are rare because they only last for a relatively short time after the formation of a galaxy. Eventually, the massive black hole in the center of the galaxy gets its fill and stops shooting out jets. Astronomers believe that the Milky Way galaxy had a quasar in its early years, and it's possible that it could have one soon (millions of years). Evidence for this crazy idea is based on the fact that the massive black hole in the center of our galaxy appears to be heating up (the accretion disc around its even horizon is emitting more radiation than expected). If this would happen it could threaten life on planets in the Milky Way. This is the least of our problems.

Thanks for reading.