Astronomers Discover Pair of Black Holes In Inactive Galaxy

William Robinson (875390) writes "The Astronomers at XMM-Newton have detected a pair of supermassive black holes at the center of an inactive galaxy. Most massive galaxies in the Universe are thought to harbor at least one supermassive black hole at their center. And a pair of black holes is indication of strong possibility that the galaxies have merged. Finding black holes in quiescent galaxies is difficult because there are no gas clouds feeding the black holes, so the cores of these galaxies are truly dark. It can be only detected by this 'tidal disruption event'."

Re:Any chance of finding gravitational waves?

[Anonymous Coward]

Unfortunately the black holes are separated by a distance about a billion times their size, which makes energy loss by gravitational waves rather small, and would be difficult to see a change in their orbital period. Also, their separation is by a couple thousand light years, so it would take a long observation to see much change in their orbital position, and the frequency of the emitted gravitational waves would be very, very, very low. If there were a test here, it would probably be very subtle. The prime candidates would be things close together, orbiting on the time scale of seconds or less right before a collision.

Re:Any chance of finding gravitational waves?

[rotorbudd]

. Also, their separation is by a couple thousand light years,

TFA reads:
"The separation between the black holes is quite small: 0.6 milliparsecs, or about 2 thousandths of a light year. That's about the width of our Solar System."
So gravitation waves might be seen AT that distance

Re:Inactive?

[DudemanX]

It's "inactive" in the sense that it isn't Active [wikipedia.org]. The Milky Way is also inactive.

I'm guessing that if these two black holes get close enough then that galaxy could get very active very quickly.