New radio observations of the Milky Way are exposing hidden patterns in its magnetic field.
People have scanned the night sky for ages, but some of the Milky Way’s most important features cannot be seen with ordinary light. Dr. Jo-Anne Brown, PhD, is working to chart one of those hidden ingredients: the galaxy’s magnetic field, a vast structure that can influence how gas moves, where stars form, and how cosmic particles travel.
“Without a magnetic field, the galaxy would collapse in on itself due to gravity,” says Brown, a professor in the Department of Physics and Astronomy at the University of Calgary.
“We need to know what the magnetic field of the galaxy looks like now, so we can create accurate models that predict how it will evolve.”
In January, Brown and her colleagues reported their results in two papers in The Astrophysical Journal and The Astrophysical Journal Supplement Series. Beyond the scientific conclusions, the team is also releasing a complete dataset intended for broad use, giving researchers around the world a new reference point for studying the Milky Way’s magnetized environment and testing ideas about how the field developed.
A New View of the Radio Sky
To build that dataset, the team turned to radio observations, which can probe regions of the galaxy that visible light cannot easily reveal.
They used a new telescope at the Dominion Radio Astrophysical Observatory in B.C., a National Research Council Canada facility, to scan the northern sky across multiple radio frequencies, an approach that helps separate and untangle overlapping signals along the same line of sight.
