Using data from the Hubble Space Telescope, a team of astronomers has captured two supermassive black holes colliding at the center of two merging galaxies.
The discovery proves that the merging of two galaxies contributes to the growth of giant black holes. This will help scientists understand how supermassive black holes, including the one at the center of the Milky Way, became so large.
The findings were published on Nov. 7 in the journal Nature.
Supermassive Black Hole Collision
The team led by Michael Koss of Eureka Scientific Inc. performed a large survey and observed a total of 481 galaxies — 385 from data collected by Hubble and 96 from the W.M. Keck Observatory in Hawaii. All in all, the targeted galaxies had an average distance of about 330 million light years from Earth.
From the collection of data, the team identified Galaxy NGC 6240 which was at the late stage of its merger. Its two cores are already nearly melded, an event obscured by the clouds of dust and gas around it. Using a combination of high-spatial-resolution infrared imaging and high-sensitivity hard X-Ray observations, the team was able to detect the merging of the of the two cores.
The photos taken by Hubble and the W.M. Keck Observatory represent the closest pass of two black holes ever seen at just about 3,000 light years apart.
"Seeing the pairs of merging galaxy nuclei associated with huge black holes so close together was pretty amazing," said Koss in a statement. "The images are pretty powerful since they are 10 times sharper than images from normal telescopes on the ground."
How Monstrous Supermassive Black Holes Are Born
It is believed that there are supermassive black holes at the center of major galaxies. Sagittarius A* at the center of the Milky Way is an example. When two major galaxies collide, the supermassive black holes at their centers also merge, creating an even bigger black hole.
However, observing the event has proven to be a challenge to astronomers. Merging galaxies usually have a thick curtain of dust and gas around its center, obscuring the view from astronomers on Earth.
By using the Keck Observatory's AO system, the team was able to pierce through the thick veil of dust and gas to see the event. This proves once and for all that the merging of the galaxies play a hand in the creation of monstrously large supermassive black holes across the universe.