Population III Star Formation in Magnetized Primordial Clouds
  The evolution of primordial collapsing clouds and formation of
proto-Population III stars are investigated using three-dimensional ideal MHD
simulation. We calculated the evolution of magnetized primordial clouds from
the prestellar stage until the epoch after the proto-Population III star
formation, spatially resolving both parsec-scale clouds and sub-AU scale
protostars. The formation process of proto-population III star is characterized
by the ratio of rotational to magnetic energy of the parent cloud. When the
rotational energy is larger than the magnetic energy, fragmentation occurs in
the collapsing primordial cloud before the proto-Population III star formation
and binary or multiple system appears. Instead, when the magnetic energy is
larger than the rotational energy, strong jet with >100km s^-1 is driven by
circumstellar disk around the proto-population III star without fragmentation.
Thus, even in the early universe, the magnetic field plays an important role in
the star formation process.
