EAPSI: Testing mechanisms for star formation via supercomputer simulations

Wu Benjamin, Gainesville FL

Investigators

Abstract

The problem of how stars form is one of the key questions in modern astrophysics, with the evolution of the universe, structure of galaxies, and creation of planetary systems all inextricably tied to star formation. All current star formation exists within giant molecular clouds (GMCs)-the coldest, densest regions of the interstellar medium, but the initial conditions and specific process through which this occurs are still uncertain. One theory posits that the dominant mechanism for star formation is through triggering via collisions between GMCs. This project will test the cloud-collision theory by creating detailed numerical simulations to investigate GMC interactions. Regions of interstellar gas, hundreds of light-years across, will be evolved over millions of years using supercomputers. The resulting structures will be analyzed in detail to determine the likelihood of stars forming. The research will be conducted in collaboration with Dr. Fumitaka Nakamura, an expert in both star formation theory and numerical simulation, at the National Astronomical Observatory of Japan. This project will be the first to rigorously implement supersonic turbulence, magnetic fields, and complex thermo-chemical functions in order to create the most realistic model of GMCs thus far. The numerical methods utilized to evolve the clouds will be magnetohydrodynamics (MHD) with adaptive mesh refinement (AMR). A state-of-the-art thermo-chemical function will also provide diagnostics to compare with observations. Clump-finding algorithms and virial analysis will be used to determine the ability of cloud collisions to compress material and initiate collapse into stars. Various parameters will be explored, including magnetic field strength and orientation, as well as collision velocity and turbulent power spectra. This research will not only further development of advanced numerical methods, but determine the importance of a potentially vital mechanism "cloud collisions" in the star formation process. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.