WoU-MMA: Role of the Dynamo Effect in Neutron Star Mergers

Princeton University, Princeton NJ

Investigators

Abstract

When neutron stars, which are some of the most spectacular compact objects in the Universe, merge, they launch powerful jets that move nearly at the speed of light. To predict the formation of these jets, it is necessary to understand how accompanying magnetic fields are spontaneously produced during neutron star mergers. The present award will focus on the so-called “dynamo effect,” which accounts for the emergence of magnetic fields from turbulence. Understanding the role of the dynamo effect is crucial for our understanding of multi-messenger astrophysical sources and thus addresses goals of NSF's "Windows on the Universe: The Era of Multi-Messenger Astrophysics". The magnetic field necessary for launching astrophysical jets may be generated in at least two locations: in the shear layer between the neutron stars when they first come into contact, and, if the remnant is a black hole, in the flow of accreting material immediately following the merger. The goal of this effort is to elucidate from first principles the dynamo produced by the Kelvin-Helmholtz instabilities in the pre-merger phase, and the magnetorotational instability and the Rayleigh-Taylor instability in the post-merger phase. The award will also support engagement with the Princeton Pre-Doctoral Fellowship Initiative, strengthen the current partnership of Princeton University with the American Physical Society Bridge Program, and enable involvement of undergraduates in synergistic research projects. 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.