Weekender: Black Holes to Rip Galaxy Apart–or has It Already Happened?

Two supermassive black holes are circlling each other–or they were, a million years ago, in a galaxy far away. In all probability, that galaxy is now being torn apart by the titanic equivalent of 100 million supernovas. So, did any civilizations experience the end of their worlds in that galaxy? If so, they would have been able to calculate the moment of their destruction down to the last second, an to have known about it for a very long time.

At the center of every galaxy – according to Einstein’s theory of general relativity – sits a light-sucking black hole that weighs the equivalent of millions or even billions of suns. Though normally quiescent, they can eat stars and gas for breakfast and belch quasars brighter than their own galaxy.

Now, it seems, that either two supermassive black holes – less than a light year apart – are circling each other in a passionate cosmic mating dance that will culminate (in about a million years) in the release of reverberations equivalent to 100 million violent supernova explosions that will wreak havoc on the remote galaxies in which they are situated …. OR prediction of such an event could all be based on a statistical error resulting from inadequate checking of the apparent flicker in a quasar. (Or rather, they were. Light from the galaxy takes so long to reach us, that the actual events happened eons ago.)

So far, the evidence – though not yet conclusive – bodes well for our being able to witness this titanic event, as the light from it, now a million years old, reaches our telescopes. And if true, it will be a boon for the nascent field of gravitational wave astronomy.

When such a mating does occur, according to theory, stars will be blown away ‘like shingles in a tornado’ by the violent ripples of space-time, according to Dr. S. George Djorgovski of the California Institute of Technology. And if scientists are correct about the impending nuptials hinted at by the flicker – it will give scientists a preview of what is likely to happen when the Milky Way collides with the Andromeda galaxy a few billion years from now.

Galaxies, like people, are merging with each other all the time. Unfortunately, however, the spasmodic climax of such a union, which comes replete with streaming jets issuing forth from one or both of the black holes (as above, so below), can never be fully witnessed. For those short, sweet, intense moments in cosmic time require about a million years in human time.

Indications of the mating dance came from the Catalina Real-Time Transient Survey, which has been monitoring the brightness of 247,000 known quasars with telescopes in Arizona and Australia for nearly a decade. Since only the relative proximity of one black hole to another could cause the 14% fluctuation detected over a 5-year period in the galaxy known as PG 1302-102, the explosive collision seems highly likely.

According to the 1/7/15 NY Times article by Dennis Overbye, the mating dance cannot be observed by any telescopes on Earth because “the black holes are circling each other at a range of 180 billion miles.” They are also too close to each other for their union to be simulated by a supercomputer. “To find out what happens, astronomers will have to build gravitational wave detectors and wait and watch,” Overbye writes.