Supermassive Black Hole Sings for Its Supper: Scientific American

[Ivan Seeking]

Astronomers have discovered the longest-running symphony in a cluster of galaxies more than 250 million light-years from Earth. Results from NASA's Chandra X-ray Observatory announced yesterday indicate sound waves are emanating from a supermassive black hole located at the center of the Perseus Cluster. It is impossible to hear the black hole's song, however, because its pitch is more than a million, billion times lower than the limit of human hearing

http://www.sciam.com/article.cfm?chanID=sa003&articleID=0009748F-3954-1F5E-905980A84189EEDF

[kikuchiyo]

I'm not in any way qualified to comment on black holes, but it was my understanding that nothing could escape its grasp, including light. (hence the black hole) So what gives, how can it emanate sound waves?

[thed]

The Hole is not emananting souds waves per se. Material hitting the event horizon does so with enormous energy, some of that causes huge shock waves in surrounding gas/dust. This is what Chandra is seeing.

[kikuchiyo]

This wave is coming from the edge of the black hole? So there is a point where matter can escape. This must be similar to the images of a black hole venting. The force of the excess matter being shifted aside must be greater then the force drawing the rest in.