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.
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