Research by astronomers at the University of Toronto suggests that the solar system is surrounded by a magnetic tunnel that can be seen in radio waves.
Jennifer West, a research assistant at the Dunlap Institute for Astronomy and Astrophysics, makes a scientific case that two bright structures seen on opposite sides of the sky — previously considered separate — are actually connected and made up of rope-like filaments. The connection forms what looks like a tunnel around our solar system.
The results of West’s research data have been published in Astrophysical Journal.
“If we looked up in the sky, we would see this tunnel-like structure in almost every direction — that is, if we had eyes that could see radio light,” West says.
West says astronomers dubbed the “North Polar Spur” and “Fan Region” have known about these two structures for decades. But most scientific explanations have focused on them individually. By contrast, West and her colleagues believe they were the first astronomers to connect them as a single unit.
Made up of charged particles and a magnetic field, the structures are shaped like long ropes, and are located about 350 light-years away from us – and are about 1,000 light-years long.
“This is the equivalent distance traveled between Toronto and Vancouver two trillion times,” West says.
West has been thinking about these features in and out for 15 years — ever since she first saw a map of the radio sky. Recently, she built a computer model that calculates what the radio sky would look like from Earth as she changed the shape and position of the long ropes. This model allowed West to “build” the structure around us, and showed her what the sky would look like through our telescopes. It was this new perspective that helped her match the model to the data.
“A few years ago, one of our co-authors, Tom Landecker, told me about a paper from 1965—from the early days of radio astronomy,” West says. “Based on raw data available at this time, the authors [Mathewson and Milne], conjecture that these polarized radio signals could originate from our view of the local arm of the galaxy, from within it.
“That paper inspired me to develop this idea and connect my model to the vastly better data our telescopes give us today.”
West uses a map of the Earth as an example. The North Pole is at the top and the equator is through the middle – unless you redraw the map from a different perspective. The same is true for the map of our galaxy. “Most astronomers look at a map with the galactic north pole at the top and the galactic center in the middle,” West explains. “The important part that inspired this idea was to redraw that map with a different point in the middle.”
“This is very smart work,” says Brian Gensler, a professor at the Dunlap Institute and author of the publication. “When Jennifer first showed this to me, I thought it was so ‘cool’ that it was hard for her to have a possible explanation. But she finally managed to convince me. Now, I’m excited to see the reaction of the rest of the astronomy community.”
An expert on magnetism in galaxies and the interstellar medium, West looks forward to more possible discoveries associated with this research.
“Magnetic fields do not exist in isolation,” she says. “They should all contact each other. So, the next step is to better understand how this local magnetic field relates to the galactic magnetic field on a large scale, as well as to the smaller magnetic fields of our Sun and Earth. “
Meanwhile, West agrees that the new “tunnel” model not only brings new vision to the scientific community, but also introduces a groundbreaking concept for the rest of us.
“I think it’s great to imagine that these structures are everywhere whenever we look up at the night sky.”
Reference: “A Unified Model of the Fan Region and the North Polar Spur: A Set of Filaments in the Local Galaxy” by J.L. West, T.L. Landecker, B.M. Gaensler, T. Jaffe, and A.S. Hill, Accepted, Astrophysical Journal.