A University of Iowa astrophysicist has been awarded funding from NASA to create imaging technology that could generate a fuller photographic scope of the Milky Way galaxy.

Dustin Swarm, a postdoctoral research scholar in the Department of Physics and Astronomy, will use the award to design multi-layered coatings for grazing incidence optical technology. This technology relies on thin mirrors stacked upon each other. Light then reflects from the stacked mirrors at a small angle — known as the grazing incidence angle, nearly parallel to the mirror surface. Physicists can modify the mirrors to control in minute degrees the angle from which light is reflected and, in turn, photograph objects far away in the night sky.

Currently, grazing incidence optical technology is only feasible for some types of light, such as X-rays. When light is more energetic than X-rays, it becomes hard to control and the angle needed to be captured by the mirror system becomes very small. This means that the reflected light rays meet at a single point, known as the focal point, far from the surface of the mirrors, undermining the practicality of optical imaging technology.

Swarm aims to address this challenge through multi-layer surface coatings for the mirrors, which would increase the angle by which the light reflects from the optical system and reduce the distance where the light rays meet at the mirrors’ focal point. 

The advance would mean the optical imaging technology could capture energetic light waves known as soft gamma rays. These rays, when captured by the mirrors, could render high-quality images of the galaxy. 

“When positrons [positively charged electrons] and classical electrons interact, they produce gamma rays. Creating a telescope that can focus on soft gamma rays will allow us to determine how positrons are generated in our galaxy, whether this is through dark matter annihilation or black holes that can consume matter,” Swarm says.

Casey DeRoo, assistant professor in the Department of Physics and Astronomy, is a co-investigator on the project.

The three-year award from NASA’s Advanced Research Projects Agency is for $1 million.