Impact of magnetic fields on Population III star formation

The theory of the formation first stars in Universe, so-called Population III (Pop III), has until now largely neglected impact magnetic fields. Complementing a series recent studies magneto-hydrodynamic (MHD) aspects Pop star formation, we here carry out suite idealized numerical experiments where ascertain how fragmentation properties primordial protostellar discs are modified if MHD effects present. Specifically, starting from cosmological initial conditions, focus on central region select minihalo at redshift $z\sim$ 25, inserting field an intermediate evolutionary stage, normalized to fraction equipartition value. To explore parameter space, consider different geometries, including uniform, radial, toroidal, and poloidal configurations, with toroidal configuration being most realistic. collapse gas is followed for $\sim$8 orders magnitude density after was inserted, maximum $10^{15}{\rm \,cm}^{-3}$ reached. We find that leads delay gas. Moreover, strongest effect as it inhibits emerging disc surrounding core more massive core. full understanding Pop~III their mass distribution thus needs take into account further conclude ideal only step this endeavor, be followed-up comprehensive treatment dissipative effects, such ambipolar diffusion Ohmic dissipation.