The most distant known galaxy to host a supermassive black hole has been discovered in a galaxy that formed in the early history of the universe.
The galaxy, as large as the Milky Way, is about 12.8 billion light-years away and harbors a supermassive black hole that contains at least a billion times as much matter as our sun. The universe is about 13.7 billion years old, and faraway objects like this are seen as they existed near the dawn of time, their light just now arriving at Earth.
The find, to be detailed in the journal Monthly Notices of the Royal Astronomical Society later this month, was unexpected:
"It is surprising that such a giant galaxy existed when the universe was only one-sixteenth of its present age, and that it hosted a black hole one billion times more massive than the sun. The galaxy and black hole must have formed very rapidly in the early universe," said Tomotsugu Goto of the University of Hawaii and part of the team that made the discovery.
The previous record holder for most distant host galaxy, found in 2005, was located at 12.5 billion light-years away, making the new finding "a significant jump," Goto told SPACE.com.
The most distant known black hole itself sits on the cusp of the 13 billion light-year mark, and was discovered in 2007. In June of this year, astronomers announced another black hole benchmark of the most massive black hole known.
Astronomers can't see black holes, but they presume their presence by noting the mass that circles around them and calculating the gravity that must be at play. Gathering information about host galaxies of supermassive black holes is important in order to understand the long-standing mystery of how galaxies and black holes have evolved together.
Until now, studying host galaxies in the distant Universe has been extremely difficult because the blinding bright light from the vicinity of the black hole (generated by all the matter it hungrily sucks in) makes it more difficult to see the already faint light from the host galaxy.
"We have witnessed a supermassive black hole and its host galaxy forming together. This discovery has opened a new window for investigating galaxy-black hole co-evolution at the dawn of the Universe," said team member Yousuke Utsumi of the National Astronomical Observatory of Japan.
Unlike smaller black holes, which are known to form when a large star dies, the origin of the supermassive black holes remains a mystery. One current suggestion is that these whoppers form when several intermediate black holes merge. The host galaxy discovered in this work provides a reservoir of such intermediate black holes.
To see the supermassive black hole, the team of scientists used new red-sensitive Charge Coupled Devices (CCDs) installed in the Suprime-Cam camera on the Subaru telescope on Mauna Kea.