Windows on the Universe: Nuclear Astrophysics at FRIB

The nuclear astrophysics group at the Facility for Rare Isotope Beams (FRIB) will use accelerator facilities to address the long-standing question about the origin of the elements in the Universe, and how new elements continue to be produced in various astrophysical sites. The goal is to restage in the laboratory the same nuclear reactions that produce new elements in nova and supernova explosions, merging neutron stars, accreting neutron stars, and other extreme astrophysical environments.

The reacting atomic nuclei are unstable and need to be produced at a rare isotope facility, like FRIB, or other world-leading laboratories. Reaction experiments are carried out, where the relevant isotopes can be produced and detected within fractions of a second. Alternatively, the properties of the exotic nuclei that participate in the astrophysical reactions are studied to infer how they would react with other nuclei.

The new nuclear information will be implemented in computer models that are then confronted with multi-messenger astronomical observations using infrared, visible light, gamma rays, gravitational waves, neutrinos, and stardust from various astrophysical sites. Only in combination with the relevant nuclear data do these observations become truly “Windows on the Universe” and reveal what elements are created in different astrophysical environments.

The proposed program of studies at the intersection of nuclear physics and astrophysics will attract a diverse group of undergraduate and graduate students, as well as postdocs to nuclear science, taking advantage of the compelling science of the NSF Big Idea "Windows on the Universe". Students and postdocs will receive broad interdisciplinary training taking advantage of the synergistic connections nationally and internationally within the IReNA network and also locally at Michigan State University with the Astronomy group and the new Department of Computational Mathematics Science and Engineering.

This will continue the excellent educational track record of the group in preparing students and postdocs for successful careers in academia, industry and US national laboratories and will thus contribute to the workforce with nuclear science expertise that is critical for the nation. To further increase interest in STEM careers in general, and nuclear-science careers specifically, especially among women and minorities, the PI team will continue to organize the very successful annual Nuclear Science Summer School (NS3).

NS3 provides undergraduate students access to nuclear science education that is not available at their home institutions and takes advantage of the compelling science in this proposal to attract and educate students.

In the era of multi-messenger astronomy the interpretation of astronomical observations using light, gamma-rays, gravitational waves, and neutrinos requires an understanding of the nuclear processes that create these various messengers. We propose to continue the experimental nuclear astrophysics program at FRIB and other facilities to provide this important nuclear physics input.

We will carry out a synergistic and interconnected experimental program using stable and rare isotope beams that employs a wide variety of existing experimental equipment, and continued development of key experimental capabilities. The proposed experiments either measure astrophysical reactions directly as they occur in nova and supernova explosions, neutron star mergers, accreting neutron stars, and other astrophysical sites, or provide indirect constraints on such reactions.

The program takes advantage of the unique capabilities of FRIB and other current facilities around the world in a complementary way. Interpreting multi-messenger observations with accurate nuclear physics obtained in the proposed program will open a new window on the universe providing insight into element synthesis and nuclear matter in extreme astrophysical environments.

This provides the opportunity to address long standing questions in nuclear science identified in the NP2010 National Academy study and the 2015 nuclear science long rage plan, including the questions the awardees aim to address here “Where do the chemical elements come from, and how did they evolve?”, “How does structure arise in the universe and how is it related to the emergence of the elements in stars and explosive processes?”, and “What is the nature of matter at extreme temperatures and densities?” These questions will be addressed by advancing our knowledge of stellar nuclear processes through laboratory experiments in close collaboration with nuclear theorists and astrophysicists. The group will perform experiments providing new data on nuclear processes in Novae, X-ray bursts, and Supernovae, will measure a range of nuclear properties needed to understand the synthesis of heavy elements by rapid and intermediate neutron capture, and will study weak interactions in supernovae and neutron stars.

This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.