Neighboring Black Holes Defy Predictions of Violent Interactions
Around the cosmos, black holes aren’t known for being the nicest neighbors. They tend to make their presence felt in unpleasant ways, pulling nearby matter inward even as they belch out violent blasts of plasma and radiation. Put two of them in the same neighborhood and the resulting tug-of-war can quickly turn ugly. But in a cluster of stars within the Milky Way, two black holes appear to have taken up residence in surprisingly close proximity.
The two relatively lightweight black holes in M22, a so-called globular cluster some 10,000 light-years away containing hundreds of thousands of stars, may represent a much larger total population, which would run counter to predictions that gravitational interactions between black holes in the cluster would eject almost all the black holes in short order. Astronomers from the U.S., England and Australia announced their discovery in a study published in a recent issue of Nature.