Supercomputer: Magnetic Fields Keep Milky Way’s Central Black Hole Hungry – For Now

September 7, 2011 in in_the_news

Largest Computer Simulation Peers into Dark Black Hole in Milky Way’s Centre

Toronto, Aug 24, 2011 /CNW/ – Telescopes can see light from distant galaxies; but it takes a supercomputer to see why the centre of our own is so dark.

The intense gravity near black holes makes for a violent, active region of space. Gas or stars that wander too near are torn apart, their energy released as X-rays. In the centre of the Milky Way, 26,000 light years away, is a black hole over four million times heavier than our Sun, but only modestly brighter.  It’s eerily quiet — too quiet.

This mystery may have been solved by an international team of scientists lead by researchers at the Canadian Institute of Theoretical  Astrophysics, and the University of Toronto Department of Astronomy and  Astrophysics, in work to be published this month in Monthly Notices of  the Royal Astronomical Society. The team used supercomputers at SciNet  of the University of Toronto, performing the largest computer  simulations ever performed in Canada, to test out their new theory.

“We’ve long thought that magnetic fields can choke off the flow of material into the black hole” says Prof. Ue-Li Pen of CITA. “Our earlier work suggested this, but then, it just wasn’t possible for a simulation  to look at the huge range of lengths – from light years to light minutes – needed to track the hot gas as it falls all the way towards the black  hole.”
“But our new methods, and SciNet, let us do just that,” added Dr. Bijia Pang. “We broke up the region of space near the black hole into 100 billion zones, and spread them over almost 18 thousands processors on SciNet’s largest cluster. This finally gave us the resolution we needed to test our model – we could see, with unprecedented accuracy,
the fields halting the turbulence and keeping the gas from falling in.”

The paper, “Numerical parameter survey of non-radiative black hole  accretion: flow structure and variability of the rotation measure”, can  be found online at

About SciNet:

SciNet is Canada’s largest supercomputer centre, providing Canadian researchers with computational resources and expertise necessary to perform their research on scales not previously possible in Canada. SciNet powers work from the biomedical sciences and aerospace  engineering to astrophysics and climate science. SciNet is part of  Compute Canada, a national infrastructure for supercomputing-powered  innovation, and is funded by CFI, NSERC, the Ontario Government, and the  University of Toronto. More information is available at


Media Contact:
Jillian Dempsey
SciNet HPC Consortium

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