荔枝视频

For centuries, astronomers have been observing celestial bodies and trying to understand the mysteries of the night sky. , PhD鈥�02, wants to map an invisible force of the Milky Way galaxy: its magnetic field.

鈥淲ithout a magnetic field, the galaxy would collapse in on itself due to gravity,鈥� says Brown, a professor in the at the 荔枝视频.

鈥淲e 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.鈥�

This month, Brown and a team of researchers have published two papers in The Astrophysical Journal and The Astrophysical Journal Supplement Series. Their discoveries include a complete dataset, which will be used by astronomers globally, and a new model that will inform theories for how the magnetic field of the Milky Way evolved.

The group used a new telescope at the in B.C., a facility, to map the northern sky across different radio frequencies.

鈥淭he broad coverage really lets you get at the details about the magnetic field structure,鈥� says Dr. Anna Ordog, BSc鈥�09 (Applied Mathematics), BSc'09 (Physics), BA鈥�13, MSc鈥�16, PhD鈥�20, and lead author of .

The result is a comprehensive, high-quality dataset, captured as part of the (GMIMS) project that maps the magnetic field of the Milky Way galaxy.

The data that was collected involved tracking an effect known as Faraday rotation.

鈥淵ou can think of it like refraction. A straw in a glass of water looks bent because of how light interacts with matter,鈥� says Rebecca Booth, BEd鈥�07, MSc鈥�21, a PhD candidate working with Brown and lead author of . 鈥淔araday rotation is a similar concept, but it鈥檚 electrons and magnetic fields in space interacting with radio waves.鈥� 

Booth鈥檚 work in the second study looked at a unique feature in the Milky Way galaxy 鈥� the Sagittarius Arm, which has a reversed magnetic field.

鈥淚f you could look at the galaxy from above, the overall magnetic field is going clockwise,鈥� says Brown. 鈥淏ut, in the Sagittarius Arm, it鈥檚 going counterclockwise. We didn鈥檛 understand how the transition occurred. Then one day, Anna brought in some data, and I went, 'O.M.G., the reversal's diagonal!'"

Booth followed up on Ordog's discovery using the dataset.

鈥淢y work presents a new three-dimensional model for the magnetic field reversal. From Earth, this would appear as the diagonal that we observe in the data,鈥� Booth explains.