Space consists of more than stars and planets. The space between them is home to a potpourri of matter in the form of gas, plasma and cosmic dust, as well as cosmic radiation and magnetic fields.

This “interstellar medium” is a building block in the structure of all galaxies – and the prime subject of Panopoulou’s interest as a researcher. She intends to focus on the magnetic field that extends within our galaxy, and how it interacts with its surroundings.

“The interstellar medium is full of gas that fuels the creation of new stars. That gas is impacted by the invisible force of the magnetic field. More knowledge about the magnetic field may therefore answer important questions about star formation and the interstellar medium’s evolution in the Milky Way,” she says.

Tracing the history of the Milky Way in its magnetic field

The magnetic field serves as a historical map. This is because earlier events in our galaxy, such as stellar explosions, galactic collisions or the formation of new stars, are seen as patterns in the field. Obtaining a clear picture of that magnetic field is therefore essential to be able to look back in time and follow events that occurred from several million years ago up to the present day.

To date, researchers have only been able to create two-dimensional images of the Milky Way’s magnetic field. Panopoulou’s research team is now endeavoring to produce a 3D image of the field and its surroundings. This may open new doors to research.

“The flat images we currently have do not reflect reality. A 3D image will add depth and perspective to what we see. We will be able to distinguish between large and small, between close and distant. It will give us completely new opportunities to measure the magnetic field, and how it has impacted the flow of gas and star formation through history,” she says.

The mapping will extend over a distance of 3,000 light years away, which represents one-twentieth of the distance from one end of the Milky Way to the other. A small part of our galaxy perhaps, but extremely important, since most of what we see in the night sky comes from this nearby volume. Panopoulou hopes that the project will pave the way for new discoveries, and an opportunity to confirm or reject various theories on the evolution of our galaxy and the interstellar medium.

“These detailed images might help to explain why star formation in our galaxy is so slow. We can also explore the dynamo theory, which explains why such strong magnetic fields can occur in galaxies,” she says.

New tools for future research

To achieve their goals, the researchers are developing new tools based on the light from stars located at a known distance from the Earth. The team will be using special optical telescopes throughout the world. Panopoulou likens the sensitive instruments to polarized eyeglasses that enable the user to see more clearly defined details.

The researchers will be taking advantage of the fact that starlight passing through the galaxy is impacted by dust that has in turn been affected by the magnetic field. They will be examining changes in the light to create an indirect picture of the magnetic field.

“Hopefully we will manage to create a methodology for the future – one that can be used to analyze ever larger data sets. This can point us in the direction for the next step forward – how we can best proceed with our research. What is really exciting is that the map will be available to everyone and can be used by other researchers to address topics that we might not even have thought of yet,” says Panopoulou.

A school project sowed the seeds

Panopoulou’s main driver has always been curiosity. As a teenager she enjoyed learning new things and was constantly asking questions. She liked it most when she herself was able to work out how to find the answer.

“As a researcher I’m still driven by that curiosity, but also by a desire to guide others as they acquire new knowledge, and to encourage their curiosity,” she says.

My research enables me to glimpse events that happened far, far away and many eons ago, events over which we have no control at all. It’s inspiring and instills humility.

She became interested in physics at an early stage, and a high school project opened her eyes to astronomy.

“I learned about the solar system and was completely hooked. That was when I fell in love with astronomy, and with space. The most fantastic thing about my research field is that I get to glimpse events that happened far, far away and many eons ago, events over which we have no control at all. It’s inspiring, and instills humility,” she says.

The grant awarded by Knut and Alice Wallenberg Foundation gives her security and independence.

“I’m incredibly grateful for the opportunity to focus on my research instead of hunting around for funding,” she says.

Text Ulrika Ernström
Translation Maxwell Arding
Photo Johan Wingborg