In a distant galaxy, a pair of black holes could be merging, and scientists on Earth have a front row seat to the event, for the first time ever.
Although the merging process could take at least a million years, we're now getting an unprecedented view of the last stages of the process, which could eventually release more energy than 100 million supernova explosions.
A group of scientists from Caltech recently discovered the two black holes after searching the skies for signs of quasars, which give off super bright x-rays and gamma rays and occur after black holes start pulling gas into their accretion disks, causing particles to spin extremely fast. Quasars appear as the brightest objects in the sky, which makes them useful for detecting black holes, which are otherwise invisible from Earth.
After collecting data from observations by a group of Earth-based telescopes, these scientists noticed a quasar flicker in galaxy PG 1302-102, which is about 3.5 billion light years from the Virgo constellation. This flicker was something we haven't seen before in a quasar, so scientists suggest that it means the presence of a second black hole in the galaxy.
"The evidence suggests that the emission originates from a very compact region around the black hole and that the speed of the emitting material in that region is at least a tenth of the speed of light," says Avi Loeb, the head of Harvard University's astronomy department. "A secondary black hole would be the simplest way to induce a periodic variation in the emission from that region, because a less dense object, such as a star cluster, would be disrupted by the strong gravity of the primary black hole."
The scientific team concluded that the two black holes, which are currently about 180 billion miles apart, are merging, a process predicted by theory. However, we've never actually observed the black hole merging process before, so what happens in PG 1302-102 could prove or disprove what we currently understand about black holes.
Although these observations still require confirmation, if proved true, we'll get a good idea what will happen to the Milky Way galaxy in a few billion years after it collides with the nearby Andromeda galaxy: both galaxies have black holes at their centers.
Of course, something else could be causing the flickers in the quasars, including material being dumped into the black holes at regular intervals from some other process, which would show up on telescopes as bursts of bright energy. However, that doesn't change the fact that scientists still believe two black holes are present in PG 1302-102.
Perhaps when the ESA's eLISA launches into space or when the Advanced LIGO is turned back on, will we know for sure. Both missions will search for the elusive gravitational waves associated with black holes.
[Photo Credit: NASA Blueshift]
