Left: The sky as it would appear in radio polarized waves. Right: The sky in the same orientation and projection as it can be seen with our eyes. | SkyNews
Left: The sky as it would appear in radio polarized waves. Right: The sky in the same orientation and projection as it can be seen with our eyes.

A radio ‘tunnel’ might surround our cosmic neighbourhood

New Canadian research suggests that a magnetic “tunnel” may surround our Solar System and tell us more about how magnetic fields behave.

A magnetic tunnel, visible in radio waves, may surround our Solar System and tell us more about how magnetic fields behave, according to new Canadian research.

Jennifer West, research associate at the University of Toronto’s Dunlap Institute for Astronomy and Astrophysics, suggests that two previously known bright structures are actually linked like a tunnel. She used a new model that is explained in detail in peer-reviewed research and added she is looking forward to feedback from the community on her findings.

The results of this study are in press at the peer-reviewed Astrophysical Journal, having been accepted for publication on October 1. A preprint version is available now at arxiv.org at this link.

Left: The sky as it would appear in radio polarized waves. Right: The sky in the same orientation and projection as it can be seen with our eyes. | SkyNews
Left: The sky as it would appear in radio polarized waves. Right: The sky in the same orientation and projection as it can be seen with our eyes.

“A good model needs to be able to explain all of the observational evidence,” West told SkyNews. “I spent quite a lot of time studying the work that has been done by many astronomers over the years, and built a picture where I tried to take into account all of the different kinds of observations. A big part of this study concerned the properties of polarized radio light, which is able to give us much more information than just the brightness alone.”

“Over the years, that observational data that we have access to has improved a lot — especially observations of polarized light. Also, the computational tools we have today are much better than even a decade ago.”

The two structures that West connected with her model are called the North Polar Spur and the Fan Region, and both have been well studied since the 1960s. West’s research is distinct not only in that it links these two structures but also in that the linkage suggests larger implications about how our Solar System is formed.

She redrew the projection of a typical galaxy map (which puts the galactic centre in the middle) to emphasize a point between the North Polar Spur and the Fan Region. Her team studied the sky at two different radio wavelengths, or frequencies: “high” frequency (30 gigahertz, or GHz) from the Planck Observatory and “low” frequency (1.4 GHz) from both the 26-metre John A. Galt Telescope at the Dominion Radio Astrophysical Observatory in Penticton, British Columbia, and Southern Hemisphere data at the same frequency from the 30-metre Villa Elisa telescope in Argentina.

“In the reprojected map, the North Polar Spur no longer appears to arch over the galactic centre,” West explained. “Rather, it looks more or less parallel to the Fan Region. The reprojected 1.4 GHz polarized radio map was my ‘eureka’ moment, when I first thought that these two bright patches could be very closely related.”

Beyond theorizing a tunnel-like structure including these two major points, West also connected her research to understand the origin of magnetism in the Universe and — more locally — the Milky Way. Scientists still poorly understand why magnetic fields formed, and what impacts they have on the formation of stars, planets and other celestial objects.

“One theory of magnetism in galaxies is called dynamo theory — it’s the theory that explains the magnetic field in the Earth and in our Sun, and that they are generated from rotating, charged particles. We think it is also responsible for generating the magnetic fields in galaxies, but we need more evidence to support this hypothesis,” West said.

As West continues her work on the magnetism link, she said one small regret is that she cannot use her hobbies of amateur astronomy or astrophotography to look at this theorized tunnel with her own eyes. “I really wish I could put on some radio glasses so that I could see this giant tunnel,” she said. “But it reminds me that there is so much more out there than what we can see.”

This biweekly column by Canadian science and space journalist Elizabeth Howell focuses on a trending news topic in Canadian astronomy and space.

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