14 DAY TRIAL // A theoretical study conducted by researchers at the Michigan State University (MSU) recently found a weird process going on in the crust of neutron stars. This process may force astrophysicists to completely reinterpret their understanding of how the outermost layer on this type of stars works.
The research group was led by Hendrik Schatz, a professor with the National Superconducting Cyclotron Laboratory at MSU. He also holds appointments with the Department of Physics and Astronomy at the university, and the Joint Institute for Nuclear Astrophysics (JINA).
Details of the investigation were published in a recent issue of the top scientific journal Nature. Schatz and his group say that their theoretical model revealed a new set of previously-unknown layers in the crust of neutron stars, which promote rapid neutrino cooling, e! Science News reports.
Neutrinos are elementary subatomic particles that interact weakly with other types of matter. Though they are not entirely without mass, their weight has never been measured accurately. Experts believe that neutrinos are extremely light even compared to other elementary particles. They also exhibit a neutral electrical charge, hence their name.
Discovering this new process casts significant doubt on our understanding of how the surfaces of neutron stars can heat themselves up. Researchers previously believed they had a clear understanding of this phenomenon, but what the MSU team found proves this belief false.
The rapid neutrino cooling the group observed is believed to be caused by nuclear reactions within the stellar crusts. “Many nuclei are round, and that suppresses the neutrino cooling. In this case, the nuclei are predicted by theorists to be 'deformed,' more football-shaped,” says study coauthor Sanjib Gupta, who is based at the IIT Ropar, in India.
“These cooling layers are pretty shallow beneath the surface. If heat from deeper within the star comes up, it hits this layer and never makes it to the surface,” Schatz adds. “This completely changes the way we think about the question of the star's hot surface. It's a big puzzle now.”
In the future, the MSU team plans to use the Facility for Rare Isotope Beams (FRIB), which is currently being built at the university, to investigate football-shaped atoms. This installation will be capable of producing a variety of atom types for scientific investigations.
The FRIB project is proposed and funded by the US Department of Energy (DOE) Office of Science.