Mysterious structures in the sky that have puzzled astronomers for decades might finally have an explanation – and it's quite something.
The North Polar Spur and the Fan Region, on opposite sides of the sky, may be connected by a vast system of magnetized filaments. These form a structure resembling a tunnel that circles the Solar System, and many nearby stars besides.
"If we were to look up in the sky," said astronomer Jennifer West of the University of Toronto in Canada, "we would see this tunnel-like structure in just about every direction we looked – that is, if we had eyes that could see radio light."
We've known about the two structures for quite some time – since the 1960s, in fact – but they have been difficult to understand. That's because it's really hard to work out exactly how far away they are; distances have ranged from hundreds to thousands of light-years away.
However, no analysis had ever linked the two structures together. West and her colleagues were able to show that the two regions, and prominent radio loops in the space between them, could be linked, solving many of the puzzling problems associated with both.
Comparison with a real tunnel showing orientation. (Left: Pixabay/wal_172619/J. West; Right: Dominion Radio Astrophysical Observatory/Villa Elisa telescope/ESA/Planck Collaboration/Stellarium/J. West)"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. Based on the crude data available at this time, the authors (Mathewson & Milne), speculated that these polarized radio signals could arise from our view of the Local Arm of the galaxy, from inside it," West explained.
"That paper inspired me to develop this idea and tie my model to the vastly better data that our telescopes give us today." READ MORE...
