Uncovering new evidence for 'event horizons' surrounding black holes

With results that fundamentally differ from earlier black hole studies, Harvard researchers have shown that some recently discovered black holes are not only ultra-dense, but actually possess event horizons that "vacuum up" energy from their surroundings. "Watching matter flowing into a black hole is like sitting upstream of a waterfall and watching the water seemingly vanish over the edge," said Ramesh Narayan, chairman of the Harvard Astronomy Department. The astronomers used NASA's Chandra X-Ray Observatory to study some of the darkest black holes yet observed. They strongly confirmed the reality of the "event horizon," the one-way membrane around black holes predicted by Einstein's theory of relativity. The findings were announced by Michael Garcia, Jeffrey McClintock, Ramesh Narayan, and Stephen Murray of the Harvard-Smithsonian Center for Astrophysics and Paul Callanan of University College, Cork, Ireland.