CAREER: Revealing the Influence of Magnetic Fields During the Formation of Planetary Systems

Planets form in protoplanetary disks composed of dust, gas, and ices as part of the star formation process. It has been hypothesized that magnetic fields play an important role in planet formation, but the detection and characterization of magnetic fields that influence protoplanetary disks remain elusive. A researcher at the Massachusetts Institute of Technology has developed a powerful observational tool to overcome the longstanding barriers in detecting and characterizing magnetic fields in planet-forming disks. This program will address two fundamental questions: 1) How widespread are magnetic fields in protoplanetary disks? and 2) When present, do these fields affect the disk structure and thus the planet formation process? The methods used to address these questions include further refinement of the novel observational tool, machine-learning (AI/ML) based modeling, and new analysis tools, which will all be made publicly available upon completion. Education initiatives include developing a new graduate course on planet formation that will be shared via an open platform, graduate student training, an undergraduate student observing program that prioritizes participation from students outside traditional STEM majors, and an outreach program that includes K-12 classroom visits with portable telescopes and tailored educational materials. The proposed program will advance research in planet formation by further developing the novel tool—based on the Zeeman splitting of spectral lines—used to simultaneously detect and characterize magnetic fields in protoplanetary disks. The research will include identifying the optimal molecular tracers of the Zeeman effect, and extending the approach to be sensitive to magnetic fields in disks viewed across a range of inclinations. Observational data from ALMA, both archival and newly obtained through this program, will be used for this purpose, and machine-learning (AI/ML) methods will be used for the analysis of the data. For those disks found to be threaded by magnetic fields, the impact of key magnetohydrodynamic (MHD) processes that impact the evolution of the planet-forming disk will be investigated via characterization of local gas pressure ratios, magnetic coupling metrics, and ion-neutral drift, all of which can affect the evolution of a disk, will be investigated. The results of this study will yield transformative insights into the role of magnetic fields in shaping the angular momentum transport, disk dispersal, and planet-forming conditions that govern the evolution of planetary systems. 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.