A magnetic tunnel could surround our solar system: study
Our entire solar system and some nearby stars could be surrounded by a vast magnetic tunnel, according to a Canadian scientist who has established a unified theory to explain two existing features in space.
On a radio map of the night sky, the North Polar Spur and the Fan Region are two bright, tendril-like gaseous features in our galaxy that emit a large amount of radio waves in many frequencies. Although they are on opposite sides of the sky, new research suggests that they are in fact connected.
“If we were to look up into the sky, we would see this tunnel-like structure in just about every direction we look – that is, if we had eyes that could see radio light,” said Dr. Jennifer West, Research Associate. at the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto, said in a press release.
West and the lead author of the new research propose that the north polar spur and fan region are part of a huge magnetic loop around our solar system, about 1,000 light-years long.
“That’s the equivalent distance to travel between Toronto and Vancouver two trillion times,” West said.
The North Polar Spur is a ridge of hot gas in our galaxy that emits radio waves and X-rays. Although it has been observed for decades, there is no consensus on its exact proximity to Earth. Theories range from the edge of the local bubble, a structure that formed around us from exploding supernovae in the Milky Way, to the edge of a much more distant larger structure, possibly outlining a huge cavity in the space.
Likewise, the fan region refers to a feature that produces an enormous amount of radio waves and is invisible to the naked eye.
According to this theory, the two are part of a tunnel that has its own magnetic field and is made up of charged particles, circling the Earth about 350 light-years away.
A new paper published as a preprint in the Astrophysical Journal points out that the north polar spur and the fan region have similar characteristics, such as “high split polarization and coherent magnetic fields” as well as cosmic ray electrons. Through computer modeling, the researchers found that if these two structures were connected by magnetized filaments, this was largely consistent with observational studies.
Previous research on the North Polar Spur and the Fan Region has focused on them individually, but this is the first to consider them part of the same system.
West created a model that allowed her to imagine what the radio sky would look like from Earth itself, so she could explain what this magnetic tunnel would look like if a person were looking at the sky from different places on Earth. .
This allowed him to cross-reference these projections of the sky with the existing data.
In an image of the sky from the new research as it would appear in polarized radio waves, the lines appear to curve inward like lines in a tunnel would as they recede.
She said in the statement that her team was inspired by a paper from 1965, when data was much more limited, which “speculated that these polarized radio signals may have come from our vision of the galaxy’s local arm, the ‘interior’.
The Local Arm, also known as the Orion Arm, is one of the spiral arms of the Milky Way galaxy, specifically the one in which our solar system is located.
“This paper inspired me to expand on that idea and link my model to the much better data that our telescopes are giving us today,” she added.
An important step was to think about the direction of the sky from a different vantage point, West said. While astronomers typically think of the sky in one orientation, having an “upward galaxy” and a “galactic center”, this center can be switched to draw a new map that offers new perspectives, much like a map of the Earth that centers the Pacific Ocean instead of the Atlantic would be very different.
Dr. Bryan Gaensler, a professor at the Dunlap Institute and one of the paper’s authors, said in the statement that he thought this theory was “too much” when West first presented it.
“But she finally managed to convince me! Now I’m excited to see how the rest of the astronomy community reacts.
Magnetic fields in space, and what they mean, are still a source of mystery in many ways. The 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.
“We still do not fully understand the origin and evolution of regular magnetic fields in galaxies and how this field is maintained,” the study says.
West added in the statement that magnetic fields all connect and interact with each other in some way.
“So a next step is to better understand how this local magnetic field connects to both the larger-scale galactic magnetic field, and also to the smaller-scale magnetic fields of our Sun and Earth.”