The pseudo-3D cube technique could change our understanding of cosmic structures and the central black holes of galaxies.

Researchers at the University of Minnesota Twin Cities College of Science and Technology have developed a new technique that reconstructs two-dimensional (2D) radio images—visual representations created from radio waves—into three-dimensional (3D) “pseudo-3D cubes” to help better understand objects in Universe.

The work was published in the journal Monthly Notices of the Royal Astronomical Society.

Traditionally, when radio images are captured in 2D, they do not allow scientists to infer what an object looks like in 3D. Converting these images into three-dimensional space can help better understand the physics of galaxies, massive black holes, jet structures and, ultimately, how the universe works.

The researchers studied polarized (radio) light—light that vibrates in a specific direction. We experience polarized light when we look at bright sunlight from a highway – it vibrates horizontally. We then use polarized sunglasses which allow only the vertical vibrating light to pass through and the glare disappears.

The research team used an effect called Faraday rotation, which changes the direction of radio-polarized waves depending on how much material they passed through. Thanks to this, they were able to estimate how far each fragment of the radio image traveled, and thus create a three-dimensional model of these phenomena occurring millions of light years away.

“We found that the shapes of the objects were very different from the impression we got just by looking at them in 2D space,” said Lawrence Rudnick, professor emeritus in the School of Physics and Astronomy at the University of Minnesota.

Using this new technique, researchers were also able to determine the direction of material ejected from massive black holes, see how that material interacts with cosmic winds or other space weather, and analyze the patterns of magnetic fields in space.

“Our technique has revolutionized our understanding of these exotic objects. We may have to reconsider previous models of the physics of how these things work,” Rudnick added. “I have no doubt that there will be many surprises in the future: some objects will not look the way we thought they would in 2D.”

Previous images will need to be reanalyzed using this new technique to confirm previous thoughts or gain new insights. Rudnick hopes to see the technique applied to images taken by new telescopes around the world.

In addition to Rudnick, the team included Craig Anderson from the Australian National University’s Research School of Astronomy and Astrophysics; William Cotton of the National Radio Astronomy Observatory; Alice Pasetto of the National Autonomous Institute of Radio Astronomy and Astrophysics of the University of Mexico; Emma Alexander from the Jodrell Bank Center for Astrophysics, University of Manchester; and Mehrnoosh Tahani of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University.

Data for this project were obtained using the MeerKAT radio telescope, a facility of the South African Radio Astronomy Observatory.