by Chris Peterson » Mon Aug 08, 2011 2:29 am
neufer wrote:However, the two central SMBHs NEVER meet.
Not so. In fact, when galaxies collide and merge, their central black holes virtually always collide. Such collisions have been modeled, and a few are suspected to be seen in observational data. It is also commonly believed that the massive black holes at the center of galaxies formed as the result of smaller black holes merging in ancient collisions.
Perhaps what you mean is that the central black holes in galaxies almost never collide directly when galaxies merge. They end up orbiting each other, and their death spiral may take a long time. But eventually they do collide.
When they do, they may form a new, more massive black hole, or one may be ejected (something that has not been observed, but is supported by an interesting theory).
[quote="neufer"]However, the two central SMBHs NEVER meet.[/quote]
Not so. In fact, when galaxies collide and merge, their central black holes virtually always collide. Such collisions have been modeled, and a few are suspected to be seen in observational data. It is also commonly believed that the massive black holes at the center of galaxies formed as the result of smaller black holes merging in ancient collisions.
Perhaps what you mean is that the central black holes in galaxies almost never collide directly when galaxies merge. They end up orbiting each other, and their death spiral may take a long time. But eventually they do collide.
When they do, they may form a new, more massive black hole, or one may be ejected (something that has not been observed, but is supported by an interesting theory).