New supercomputer models indicate that magnetic fields enable two protostars to form a close binary system by removing angular momentum from the surrounding gas.
Researchers ran advanced simulations on Japan's ATERUI III and ATERUI II supercomputers to study how binary stars form early in their development. The models showed that magnetic fields thread through the gas around newborn protostars and act to slow their orbital motion, pulling the pair inward. A control simulation without magnetic fields produced the opposite result, with the protostars drifting farther apart. The findings appear in a paper published in Monthly Notices of the Royal Astronomical Society by Tomoaki Matsumoto, Kenta Hotokezaka and Kohei Inayoshi. The same process may operate on larger scales. The team noted that magnetic fields could similarly help massive black hole pairs in young galaxies lose angular momentum and eventually merge. Further work is required to test these effects over the long timescales involved in black hole mergers. The study was supported by the National Institutes of Natural Sciences.