Artist’s impression of the huge outflow ejected from the quasar
Credit: ESO
U.S. astronomers have discovered a quasar with the most energetic outflow ever seen.
The Virginia Tech physicists discovered the quasar using the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile. ESO said the quasar was at least five times more powerful than any that have been observed to date.
Quasars are extremely bright galactic centres powered by supermassive black holes. Many blast huge amounts of material out into their host galaxies, and these outflows play a key role in the evolution of galaxies. But, until now, observed quasar outflows weren’t as powerful as predicted by theorists.
The quasar, known as SDSS J1106+1939, has been studied in great detail by the researchers, using the X-shooter instrument on ESO’s VLT at the Paranal Observatory.
Virginia Tech’s team leader Nahum Arav said: “We have discovered the most energetic quasar outflow known to date. The rate that energy is carried away by this huge mass of material ejected at high speed from SDSS J1106+1939 is at least equivalent to two million million times the power output of the Sun. This is about 100 times higher than the total power output of the Milky Way galaxy — it’s a real monster of an outflow.
“This is the first time that a quasar outflow has been measured to have the sort of very high energies that are predicted by theory.”
The team said the finding could answer questions about how the mass of a galaxy is linked to its central black hole mass and why there are so few large galaxies in the universe.
Arav said: “For the last 15 years many theorists have said that if there were such powerful outflows it would help answer many questions on the formation of galaxies, on the behavior of black holes, and on the enrichment of the intergalactic medium with elements other than hydrogen and helium.
“This discovery means we can better explain the formation of galaxies. There are hundreds of people doing the theoretical side of the work. They hypothesize outflows in their simulations, and now we’ve found an outflow in the magnitude that has only been theorized in the past. Now they can refine their already impressive models and base them on empirical data.”
The newly discovered outflow lies about a thousand light-years away from the supermassive black hole at the heart of the quasar SDSS J1106+1939. The team’s analysis shows that a mass of approximately 400 times that of the Sun is streaming away from this quasar per year, moving at a speed of 8000 kilometres per second.
As well as SDSS J1106+1939, the team also observed one other quasar and found that both of these objects have powerful outflows. As these are typical examples of a common, but previously little studied, type of quasars, these results should be widely applicable to luminous quasars across the Universe. The team are currently exploring a dozen more similar quasars to see if this is the case.
“I’ve been looking for something like this for a decade,” said Arav, “so it’s thrilling to finally find one of the monster outflows that have been predicted!”
