Most galaxies have massive black holes at their center. But, what happens to these black holes when a pair of galaxies merge? The leading theory is the black holes form a “binary.”
Researchers from the University of Maryland have just released a new study where they show direct evidence of a pulsing quasar. They believe this pulsing quasar supports the theory of black hole binaries.
“We believe we have observed two supermassive black holes in closer proximity than ever before,” said Suvi Gezari, assistant professor of astronomy at the University of Maryland and a co-author of the study. “This pair of black holes may be so close together that they are emitting gravitational waves, which were predicted by Einstein’s theory of general relativity.”
As black holes suck in matter, they create some of the brightest objects ever found in the universe – quasars. If there are a pair of black holes orbiting as a binary, they absorb matter in cycles. Researchers theorize these cycles would cause the quasar to pulse brighter and then to dim.
Researchers turned to the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) Medium Deep Survey to find pulsing quasars.
While sifting through the data, they came across PSO J334.2028+01.4075. This quasar was part of a very large black hole of nearly 10 billion solar masses. What caught the researchers’ attention was it emitted a periodic optical signal every 542 days.
“The discovery of a compact binary candidate supermassive black hole system like PSO J334.2028+01.4075, which appears to be at such close orbital separation, adds to our limited knowledge of the end stages of the merger between supermassive black holes,” said UMD astronomy graduate student Tingting Liu, the paper’s first author.
Finding one pulsing quasar isn’t enough. The researchers will continue hunting for new so-called variable quasars. In 2023, they’ll get a brand new telescope to hunt down merging black holes – the Large Synoptic Survey Telescope (LSST).
“These telescopes allow us to watch a movie of how these systems evolve,” said Liu. “What’s really cool is that we may be able to watch the orbital separation of these supermassive black holes get smaller and smaller until they merge.”
The Large Synoptic Survey Telescope is being built on a mountaintop site in Chile. The 8.4-meter ground-based telescope will image the entire sky every few nights with its massive camera.
The LSST’s camera puts the camera on your phone to shame. An iPhone 6 has an 8-megapixel camera. The LSST? Try 3200 megapixels. It’s the world’s largest digital camera.
Here’s a 2013 rendering of what the telescope will look like it.
And, a picture of the telescope’s massive mirror.
Image credits: NASA, LSST