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'Monster' quasar sheds light on galaxies

quasar SDSS J1106+1939

The huge outflow seen ejecting from a quasar could explain how galaxies evolve (Source: European Southern Observatory )

Black hole blast Astronomers have discovered a massive blast coming from a black hole, five times more powerful than any previously seen.

The discovery will help scientists understand how galaxies evolve, and provide clues about their relationship with supermassive black holes at their centre.

Quasars are powerful streams of plasma and energy that are generated by matter being destroyed as it falls into black holes.

The blasts often extend for light years, and are bright enough to be seen right across the universe.

Lead scientist, Professor Nahum Arav from Virginia Tech says the quasar, called SDSS J1106+1939, has an output two trillion times that of the Sun.

"This is about 100 times higher than the total power output of the Milky Way galaxy so it's a real monster," says Arav.

"I've been looking for one of these monster outflows for a decade, it's thrilling to finally see one."

Linking galaxies and black holes

Theoretical simulations suggest these outflows generate a feedback mechanism on the galaxies around them, causing the size of the galaxy to be tied to the mass of its central black hole.

This would also help explain why there are so few really big galaxies.

Writing in the Astrophysical Journal, Arav and colleagues found the outflow extending 1000 light-years from the supermassive black hole generating it, and moving at 8000 kilometres per second.

"Until now, we still weren't sure if quasars were capable of generating outflows powerful enough to produce these effects," says Arav.


Shaping galaxies

Dr Paul Francis of the Australian National University's Mount Stromlo Observatory says the discovery provides insights into how galaxies form.

"This helps solve a mystery as to why there are two types of galaxies," says Francis.

"Galaxies either become elliptical or they become flat spiral disks like the Milky Way."

Disk galaxies look blue because there's a lot of star formation going on, while ellipticals are more red because they contain lots of older stars, but little new star formation.

"No-one's quite been able to tell why they're different," says Francis.

"We think quasars may play a role in this by blowing gas out of a galaxy which would otherwise go into making more stars, and so it becomes a red galaxy."

"But until now we hadn't found any quasars powerful enough to do that. Now we have."

Tags: blackholes, physics, galaxies