Last week I wrote about Black Hole scale and in it I mentioned Quasi-Stellar Radio Sources, or Quasars for short. Since I think Quasars are such an interesting topic, they will be the subject I write on this week.
Quasars were discovered in the late 1950’s, when astronomers found strange radio-wave emitting points in the sky. It seemed like they burned like stars, and yet they outshined galaxies. They also emitted radio waves, and so they were named Quasi-Stellar Radio Sources.
Quasars are nuts. They are Supermassive or Ultramassive Black Holes fed by the gas of their galaxy swirling in around them and shooting it into space at around the speed of light. (For context, that’s about 40 million miles per hour.) These gas jets shoot out into space, creating “radio-lobes” that can be light-years across. The gas closest to the Black Hole is heated up so much that it shines like the sun, only this is a trillion times more efficient at making light, meaning it can light up a galaxy for us to see, y’know, 600 million light years away. And that’s the closest one. The farthest Quasar we know of is 31.7 billion light years away. And we still see it. Pretty darn bright.
And Quasars have the power to kill a galaxy, more or less. By heating up the gas in the galaxy so much, it prevents star formation. Hot gas has pressure, so it pushes back against gravity, while cold gas doesn’t even try to resist, so it collapses into a star.
There is no Quasar in the Milky Way, and if there was, it would pretty much eliminate any sort of “night” as it would light up the galaxy with the luminosity of trillions of stars. We are expected to get a Quasar one day though. Scientists speculate that if the Milky Way collides with Andromeda in about 4.5 billion years, as is thought to be the case, we will end up with a Qausar, as Sagittarius A and M31 collide to create an even bigger Black Hole, Milkdromeda.
Credits:
The Wooshing King 