ASU-led astrophysics team wins Buchalter Cosmology Prize

A team led by Christopher Cain, a Beus Prize Fellow and postdoctoral researcher in Arizona State University's School of Earth and Space Exploration, has won the 2025 First Place Buchalter Cosmology Prize.

Established in 2014, the Buchalter Cosmology Prize recognizes innovative theoretical, observational or experimental work in cosmology. The award was announced on Jan. 8 at the 247th meeting of the American Astronomical Society in Phoenix. It is the first time an ASU-led team has won first prize in this competition.

The $10,000 first prize was awarded to the team, which also included ASU School of Earth and Space Exploration Professor Evan Scannapieco, for their paper entitled “Kiloparsec-scale turbulence driven by reionization may grow intergalactic magnetic fields."

The judging committee recognized the work as “a novel approach to produce nonprimordial intergalactic magnetic fields, using high-resolution radiation-hydrodynamics simulations to demonstrate that rapid ionization produces turbulence that the authors show might be sufficient to amplify intergalactic magnetic fields to levels matching observations of TeV blazars.”

"This had to be one of the most fun and rewarding projects I've ever worked on. We were not expecting to see this new physics, and it came as a fascinating and exciting surprise,” said Cain.

In this study, the authors examined how gas clouds expand in the space between galaxies, known as the intergalactic medium, after reionization. Reionization is the process where the first stars and galaxies turned neutral hydrogen in the universe into ionized hydrogen during the first billion years of cosmic history.

Reionization is thought to have greatly heated the intergalactic medium, causing small clumps of gas to expand in a process called "pressure smoothing." Using high-resolution simulations of dark matter, gas and radiation in the early universe, the authors showed for the first time that pressure smoothing can create turbulent vortices in the intergalactic medium. These vortices can help grow magnetic fields through a process called the "dynamo effect," which may explain why we can detect magnetic fields in the empty spaces between galaxies today. These results could help solve the long-standing mystery of where these fields come from.

"It was very exciting to be part of a team that uncovered a new physical process. As we pushed to higher resolution, we saw turbulence appear and realized that it could naturally amplify cosmic magnetic fields,” said Scannapieco. "It was one of those rare moments when simulations taught us something unexpected about the universe."

“This discovery embodies our drive to trace our cosmic origins and reveal the universe’s hidden engines. We’re proud of Chris and the team for identifying this important process in cosmic evolution” said Professor Judd Bowman, director of ASU’s Beus Center for Cosmic Foundations.

The prize is also shared with co-authors Matthew McQuinn from the University of Washington, Anson D'Aloisio from the University of California, Riverside, and Hy Trac from Carnegie Mellon University.