Researchers say light signal from space suggests merging black holes
Saturday, January 10, 2015
On Wednesday, George Djorgovski and collaborators reported in the journal Nature on an unusual light signal they say suggests two supermassive black holes are merging, a phenomenon never seen before, though theorized.
The discovery could clarify how black holes merge and galaxies evolve, and could also provide a better understanding of the so-called "final parsec problem" — the inability of theories to predict how, or even how quickly, the final phases of black hole mergers happen.
The team discovered the light coming from quasar PG 1302-102 in data from the Catalina Real-time Transient Survey (CTRS), which is able to study light sources from four fifths of the night sky using three ground-based US and Australian telescopes.
Coauthor and Caltech computational scientist Matthew Graham emphasized the final stages of these black hole mergers are not well understood.
CTRS has so far identified 20 quasars with similar signals, but Graham said this one is the best example because it has a clear signal that recurs about every five years, similar to a sine wave (see the 2D graph shown on the left).
- Ker Than. "Unusual Light Signal Yields Clues About Elusive Black Hole Merger" — Caltech, January 7, 2015
- Whitney Clavin. "Unusual Light Signal Hints at Distant Black Hole Merger" — NASA, January 7, 2015
- Matthew J. Graham, S. G. Djorgovski, Daniel Stern, Eilat Glikman, Andrew J. Drake, Ashish A. Mahabal, Ciro Donalek, Steve Larson, and Eric Christensen. "A possible close supermassive black-hole binary in a quasar with optical periodicity" — Nature (journal), January 7, 2015