First Look At Interstellar Turbulence


All of the space that surrounds us isn’t empty. We’ve always known the Milky Way was filled with great areas of turbulent gas, but we’ve never been able to see them… Until now. Professor Bryan Gaensler of the University of Sydney, Australia, and his team used a CSIRO radio telescope in eastern Australia to create this first-ever look which was published in Nature today.

“This is the first time anyone has been able to make a picture of this interstellar turbulence,” said Professor Gaensler. “People have been trying to do this for 30 years.”

So what’s the point behind the motion? Turbulence distributes magnetism, disperses heat from supernova events and even plays a role in star formation.

“We now plan to study turbulence throughout the Milky Way. Ultimately this will help us understand why some parts of the galaxy are hotter than others, and why stars form at particular times in particular places,” Professor Gaensler said.

Employing CSIRO’s Australia Telescope Compact Array because “it is one of the world’s best telescopes for this kind of work,” as Dr. Robert Braun, Chief Scientist at CSIRO Astronomy and Space Science, explained, the team set their sights about 10,000 light years away in the constellation of Norma. Their goal was to document the radio signals which emanate from that section of the Milky Way. As the radio waves pass through the swirling gas, they become polarized. This changes the direction in which the light waves can “vibrate” and the sensitive equipment can pick up on these small differentiations.

By measuring the polarization changes, the team was able to paint a radio portrait of the gaseous regions where the turbulence causes the density and magnetic fields to fluctuate wildly. The tendrils in the image are also important, too. They show just how fast changes are occurring – critical for their description. Team member Blakesley Burkhart, a PhD student from the University of Wisconsin, made several computer simulations of turbulent gas moving at different speeds. By matching the simulations with the actual image, the team concluded “the speed of the swirling in the turbulent interstellar gas is around 70,000 kilometers per hour — relatively slow by cosmic standards.”

Original Story Source: CSIRO Astronomy and Space Science News Release. For Further Reading: Low Mach number turbulence in interstellar gas revealed by radio polarization gradients.

Tammy Plotner

Tammy was a professional astronomy author, President Emeritus of Warren Rupp Observatory and retired Astronomical League Executive Secretary. She’s received a vast number of astronomy achievement and observing awards, including the Great Lakes Astronomy Achievement Award, RG Wright Service Award and the first woman astronomer to achieve Comet Hunter's Gold Status. (Tammy passed away in early 2015... she will be missed)

Recent Posts

Stellar Winds Coming From Other Stars Measured for the First Time

An international research team led by the University of Vienna has made a major breakthrough.…

1 day ago

Neutron Stars Could be Heating Up From Dark Matter Annihilation

Astronomers have an intriguing idea for searching for dark matter, measuring the effect of particle…

1 day ago

The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star

After a journey lasting about two billion years, photons from an extremely energetic gamma-ray burst…

2 days ago

Formation-Flying Spacecraft Could Probe the Solar System for New Physics

It's an exciting time for the fields of astronomy, astrophysics, and cosmology. Thanks to cutting-edge…

2 days ago

Watch a Satellite Reaction Wheel Melt in a Simulated Orbital Re-Entry

Most satellites share the same fate at the end of their lives. Their orbits decay,…

2 days ago

NASA is Building an Electrodynamic Shield to Deal with all that Dust on the Moon and Mars

Exploration of the Moon or other dusty environments comes with challenges. The lunar surface is…

3 days ago