Blazing the trail in multimessenger astrophysics
Michigan State University is blazing the trail in multimessenger astrophysics—a new area of science that the National Science Foundation is calling one of its ten “big ideas” for future investments in science and engineering.
“At MSU, we’re succeeding in opening a new window on the universe,” said Tyce DeYoung, associate professor of physics at MSU. “There have been tremendous discoveries in this area in the past few years, and it’s an exciting time to be involved with this type of science.”
DeYoung defines this type of astrophysics as using messengers other than light—such as electromagnetic radiation, gravitational waves, cosmic rays and, most recently, neutrinos—to learn about the universe.
MSU is one of the primary universities involved in the IceCube Neutrino Observatory at the Amundsen-Scott South Pole Station, an international collaboration of more than 300 scientists in 12 countries.
“Neutrino astronomy offers us a very different view of the universe that we can’t get from other types of telescopes,” DeYoung explained. “Neutrinos tell us what’s happening deep inside of the source, similar to a medical x-ray showing us what’s inside the human body. Better understanding the properties of these incredibly powerful astrophysical accelerators may give us insight into some of the physics that we don’t yet understand.
“Five years ago, we discovered a flux of neutrinos coming from distant objects in the universe, but we hadn’t yet identified the individual sources,” he continued. “Since that time, we’ve been working on building partnerships with other types of telescopes—gamma ray telescopes, x-ray telescopes, radio telescopes, optical telescopes—to jointly observe potential sources.”
The big break came last fall for the IceCube collaboration.
“In September 2017, we observed a very high-energy neutrino,” DeYoung said. “Based on its energy, it was likely to have come from some extragalactic source. We alerted the astronomical community to this for follow-up observations.”
Telescopes around the world detected the source in gamma rays as well. This collective data provided evidence for the first individually identified source of high-energy neutrinos.
The scientific community had discovered a blazar named TXS 0506+056—a giant elliptical galaxy with a massive, rapidly spinning black hole at its core that emits a jet of ultrarelativistic particles aimed toward us. It is situated in the night sky just off the left shoulder of the constellation Orion and is about four billion light years from Earth.
“These intriguing results represent the remarkable culmination of thousands of human years of intensive activities by the IceCube collaboration to bring the dream of neutrino astronomy to reality,” said Darren Grant, a professor of physics at the University of Alberta and current spokesperson of the IceCube collaboration.
He will join MSU’s physics and astronomy department as a professor this fall. Claudio Kopper, assistant professor of physics at the University of Alberta, and an expert in computational modeling and data analysis, will also join the MSU faculty as an associate professor this fall.
“With these new faculty, MSU will rank as one of the top institutions in IceCube, which is by far the world’s most successful neutrino telescope,” DeYoung said.
A long-term commitment from NSF and MSU is critical to advancing this area of research. MSU and its partners in the IceCube collaboration have submitted a $22.7 million proposal to NSF for an IceCube upgrade, with $1.9 million of those funds earmarked for activities at MSU.
“This upgrade will give us better angular resolution for neutrino astronomy and also enhance our measurements of neutrino properties,” DeYoung said.
In addition, MSU will directly be a major partner in the upgrade if it is approved, contributing $3.4 million toward new photosensors and establishing a sensor assembly, testing and development facility on campus.
The expected completion date for the IceCube upgrade is February 2023.
The next step is IceCube–Gen 2, the next generation observatory. This project, which would cost in the range of $300-400 million, would increase the size of the neutrino telescope by nearly a factor of 10.
“This would allow us to detect more neutrinos and see dimmer neutrino sources,” DeYoung said. “And it would greatly enhance our view of the universe through neutrinos and give us much more information on the accelerators of the highest energy cosmic rays—blazars like TXS 0506, and possibly other sources such as exploding stars, colliding galaxy clusters or whatever else the universe has in store for us.”
MSU’s Institute for Cyber-Enabled Research and the Department of Computational Mathematics, Science and Engineering will play key roles in advancing multimessenger astrophysics.