Massive Outflows Driven by Magnetic Effects in Star Forming Clouds with
  High Mass Accretion Rates
  The relation between the mass accretion rate onto the circumstellar disc and
the rate of mass ejection by magnetically driven winds is investigated using
three-dimensional magnetohydrodynamics simulations. Using a spherical cloud
core with a varying ratio of thermal to gravitational energy, which determines
the mass accretion rate onto the disc, to define the initial conditions, the
outflow propagation for approximately 10^4 yr after protostar formation is then
calculated for several cloud cores. The mass ejection rate and accretion rate
are comparable only when the magnetic energy of the initial cloud core is
comparable to the gravitational energy. Consequently, in strongly magnetised
clouds a higher mass accretion rate naturally produces both massive protostars
and massive outflows. The simulated outflow mass, momentum, kinetic energy and
momentum flux agree well with observations, indicating that massive stars form
through the same mechanism as low-mass stars but require a significantly strong
magnetic field to launch massive outflows.
