Researchers say light signal from space suggests merging black holes
Saturday, January 10, 2015
Image: NASA.
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.
Image: Geek3
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).
Sources
- 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
External links
- 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
