"If this monster was at
the center of the Milky Way it would likely make life on Earth impossible with
the huge amounts of x-rays emanating from it," said Christian Wolf with
the Australia National University Research School of Astronomy and
Astrophysics. Astronomers have found the
fastest-growing black hole known in the Universe, describing it as a monster
that devours a mass equivalent to our sun every two days.
The team looked back more
than 12 billion years to the early dark ages of the Universe, when this
supermassive black hole was estimated to be the size of about 20 billion suns
with a one per cent growth rate every one million years.
"This black hole is
growing so rapidly that it's shining thousands of times more brightly than an
entire galaxy, due to all of the gases it sucks in daily that cause lots of
friction and heat," said Wolf."If we had this monster sitting at the
centre of our Milky Way galaxy, it would appear 10 times brighter than a full
moon. It would appear as an incredibly bright pin-point star that would almost
wash out all of the stars in the sky."
Dr Wolf said the energy
emitted from this newly discovered supermassive black hole, also known as a
quasar, was mostly ultraviolet light but also radiated x-rays.
The SkyMapper telescope at
the ANU Siding Spring Observatory detected this light in the near-infrared, as
the light waves had red-shifted over the billions of light years to Earth.
"As the Universe
expands, space expands and that stretches the light waves and changes their
colour," Wolf said. "These large and rapidly-growing blackholes are
exceedingly rare, and we have been searching for them with SkyMapper for several
months now. The European Space Agency's Gaia satellite, which measures tiny
motions of celestial objects, helped us find this supermassive black
hole."
Dr Wolf said the Gaia
satellite confirmed the object that they had found was sitting still, meaning
that it was far away and it was a candidate to be a very large quasar. The
discovery of the new supermassive black hole was confirmed using the
spectrograph on the ANU 2.3 metre telescope to split colours into spectral
lines.
"We don't know how this
one grew so large, so quickly in the early days of the Universe," Dr Wolf
said. "The hunt is on to find even faster-growing black holes."
Dr Wolf said as these kinds
of black holes shine, they can be used as beacons to see and study the
formation of elements in the early galaxies of the Universe. "Scientists
can see the shadows of objects in front of the supermassive black hole,"
he said. "Fast-growing supermassive black holes also help to clear the fog
around them by ionising gases, which makes the Universe more transparent."
Dr Wolf said instruments on
very large ground-based telescopes being built over the next decade would be
able to directly measure the expansion of the Universe using these very bright
black holes.
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