TORONTO -- Our entire solar system and some nearby stars may be surrounded by a vast magnetic tunnel, according to a Canadian scientist who has set out a unified theory to explain two existing features in space.
In a radio map of the night sky, the North Polar Spur and the Fan Region are two bright, tendril-like gas features in our galaxy, which emit a large amount of radio waves in many frequencies. Although they鈥檙e on opposite sides of the sky, new research is suggesting that they are actually connected.
鈥淚f we were to look up in the sky, 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,鈥� Dr. Jennifer West, a research associate at the Dunlap Institute for Astronomy and Astrophysics with the University of Toronto,
West and the lead author of the new research propose that the North Polar Spur and the Fan Region are part of one enormous magnetic loop around our solar system, around 1,000 light-years long.
鈥淭hat鈥檚 the equivalent distance of travelling between Toronto and Vancouver two trillion times,鈥� West said.
The North Polar Spur is a ridge of hot gas in our galaxy that emits radio waves and X-rays. Although it鈥檚 been observed for decades, there isn鈥檛 consensus on exactly how close it is to Earth. Theories range from it being the edge of the Local Bubble, a structure that formed around us from supernovae exploding in the Milky Way, or it being the edge of a larger structure much farther away, possibly outlining a huge cavity in space.
Similarly, the Fan Region refers to a feature that produces a huge amount of radio waves, and is invisible to the naked eye.
Under this theory, both are part of a tunnel that has its own magnetic field and is made up of charged particles, encircling Earth around 350 light-years away.
A new paper points out that the North Polar Spur and the Fan Region have similar features, such as 鈥渉igh fractional polarization and coherent magnetic fields鈥� as well as cosmic ray electrons. Through computer modelling, researchers found that if these two structures were connected through magnetized filaments, it largely matched up with observational studies.
Previous research on the North Polar Spur and the Fan Region have focused on them individually, but this is the first to consider them as being part of the same system.
West created a model that allowed her to envision what the radio sky would look like from Earth itself, so she could lay out how this magnetic tunnel should look if a person was observing the sky from different locations on Earth.
This allowed her to cross-reference those sky projections with existing data.
In one image of the sky from the new research as it would appear in radio polarized waves, the lines appear to curve inwards the way lines on a tunnel would as it receded into the distance.
She said in the release that her team was inspired by a paper from 1965, when data was much more limited, which 鈥渟peculated that these polarized radio signals could arise from our view of the Local Arm of the Galaxy, from inside it.鈥�
The Local Arm, also known as the Orion Arm, is one of the spiral arms of the Milky Way galaxy -- specifically, the one that our solar system is within.
鈥淭hat paper inspired me to develop this idea and tie my model to the vastly better data that our telescopes give us today,鈥� she added.
An important step was thinking about the orientation of the sky from a different point of view, West said. While astronomers usually think of the sky in one orientation, having a 鈥淕alaxy up鈥� and a 鈥淕alactic centre,鈥� that centre can be switched to draw a new map that provides new perspectives, much like how a map of the Earth that centres the Pacific Ocean instead of the Atlantic would look very different.
Dr. Bryan Gaensler, a professor at the Dunlap Institute and one of the paper鈥檚 authors, said in the release that he thought this theory was 鈥渢oo 鈥榦ut-there鈥欌�� when West first pitched it.
鈥淏ut she was ultimately able to convince me! Now I鈥檓 excited to see how the rest of the astronomy community reacts.鈥�
Magnetic fields in space, and just what they mean, are still a source of mystery in many ways. Researchers state in the paper that this model could aid in the creation of a holistic model to better understand magnetic fields in galaxies as a whole.
鈥淲e still do not fully understand the origin and evolution of regular magnetic fields in galaxies and how this field is maintained,鈥� the study states.
West added in the release that magnetic fields all connect and interact with each other in some way.
鈥淪o a next step is to better understand how this local magnetic field connects both to the larger-scale Galactic magnetic field, and also to the smaller scale magnetic fields of our Sun and Earth.鈥�
