Comments on: AAS #10: Screaming black holes

By: n stone

n stone — Tue, 22 Jan 2008 05:12:42 +0000

If a supermassive black hole was rocketed out of our galaxy, what are the chances of it ripping through the lining of our universe? Is that possible? (guessing no)
Another possibility would be that if it orbited the universe leaving a trail of destruction, it would either have to end up in the center of the universe after a very long tim or else it would have to rip through the lining of the universe.
Wouldn’t it?

By: Mike

Mike — Sat, 12 Jan 2008 15:29:03 +0000

Lab Lemming: There are 3 main mechanisms by which orbiting black holes can lose energy and angular momentum, as far as I know. The first is through dynamical friction (a global transfer of energy and angular momentum to stars), the second is by super-elastically scattering stars that come near the black hole binary, and the third is by emitting gravitational radiation (by far the most efficient, but only operates when the black holes are relatively close to each other). If there is a significant amount of gas present near the black holes, then gas accretion and torques can also help get rid of angular momentum.

By: Fizzygoo

Fizzygoo — Fri, 11 Jan 2008 18:30:00 +0000

“Usually, this radiation [from merging black holes] is emitted in all directions, but sometimes it can be sent out more to one side than the other. When that happens, it acts like a rocket, pushing the black hole in the other direction.”

So, it is the asymmetry of the “explosion”/energy release (from the merging black holes) that is propelling it/them out of the cluster. The black holes have still merged.

By: Richard

Richard — Fri, 11 Jan 2008 14:28:19 +0000

I thought there “is no escape” once past the event horizon, surely another hole’s singularity is no exception to this.

By: Lab Lemming

Lab Lemming — Thu, 10 Jan 2008 22:15:10 +0000

OK, but that still doesn’t explain how orbiting black holes can lose relative angular momentum.

By: Barton Paul Levenson

Barton Paul Levenson — Thu, 10 Jan 2008 18:18:52 +0000

Earl — yes, I was referring to the Schwarzchild radius. The actual black hole is a point. But for collisional purposes, if the Schwarzchild radii intersect, you’ve got a merged black hole. Relativity and all that.

By: Gary Ansorge

Gary Ansorge — Thu, 10 Jan 2008 17:38:34 +0000

So, if a black hole is active, does that mean a life bearing planet could possibly orbit such, drawing its light from the disruption of material close in to the Black Hole? Interesting story possibility here,,,

GAry 7

Really boss photos, Phil.