Milky Way’s Monster Outflows Help Generate Galactic Magnetic Field
Created: January 3, 2013
Last Updated: January 1, 2013
Related articles: Science » Space & Astronomy
Supersonic geysers of charged particles have been discovered streaming from our galaxy’s center that span about two-thirds of the sky when viewed from Earth.
The outflows stretch 50,000 light-years out of the Galactic Plane, which is about half of our galaxy’s diamater, and contain about a million times the energy of an exploding star.
They are traveling at around 1,000 kilometers (about 620 miles) per second.
“That’s fast, even for astronomers,” said research team leader Ettore Carretti at Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO) in a press release. “They are not coming in our direction, but go up and down from the Galactic Plane.
“We are 30,000 light-years away from the Galactic Center, in the Plane. They are no danger to us.”
Microwave emission from these structures was previously picked up as a haze, and similarly the Fermi Gamma-ray Space Telescope detected highly energetic areas referred to as “Fermi Bubbles.” However, the source of this energy could not be identified.
“The options were a quasar-like outburst from the black hole at the Galactic Center, or star-power—the hot winds from young stars, and exploding stars,” said study co-author Gianni Bernardi at the Harvard-Smithsonian Center for Astrophysics (CfA) in the release.
“Our observations tell us it’s star-power.”
The astronomers looked at the polarization of the structures’ radio emission to determine their magnetic fields, and deduced that they probably developed over the past 100 million years as numerous generations of stars formed and exploded in the Galactic Center.
“The outflow from the Galactic Centre is carrying off not just gas and high-energy electrons, but also strong magnetic fields,” concluded study co-author Marijke Haverkorn at Holland’s Radboud University Nijmegen in the release.
“We suspect this must play a big part in generating the Galaxy’s overall magnetic field.”
The research was published in Nature on Jan. 3.
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