Exponentially Amplified Magnetic Field Eliminates Disk Fragmentation around Population III Protostars

Abstract One critical remaining issue that is unclear in the initial mass function of first (Population III) stars final fate secondary protostars formed accretion disk—specifically, whether they merge or survive. We focus on magnetic effects formation star under a cosmological field. perform suite ideal magnetohydrodynamic simulations for 1000 yr after protostar formation. Instead sink particle technique, we employ stiff equation state approach to represent field structure connecting protostars. Ten years cloud initialized with B 0 = 10 ?20 G at n 4 cm ?3 , strength around has amplified from pico- kilo-Gauss, which same as present-day star. The rapidly winds up since gas vicinity (?10 au) undergone several tens orbital rotations decade As progresses, vital region extends outward, and braking eliminates fragmentation disk would happen an unmagnetized model. On other hand, assuming small angular momentum, this amplification might not work because rotation be slower. However, occur case. conclude exponential strength, about ?18 G, Population III