The Simultaneous Formation of Massive Stars and Stellar Clusters
  We show that massive stars and stellar clusters are formed simultaneously,
the global evolution of the forming cluster is what allows the central stars to
become massive. We predict that massive star forming clumps, such as those
observed in Motte et al. 2007, contract and grow in mass leading to the
formation of massive stars. This occurs as mass is continually channeled from
large radii onto the central proto-stars, which can become massive through
accretion. Using SPH simulations of massive star forming clumps in a Giant
Molecular Cloud, we show that clumps are initially diffuse and filamentary, and
become more concentrated as they collapse. Simulated interferometry
observations of our data provide an explanation as to why young massive star
forming regions show more substructure than older ones. The most massive stars
in our model are found within the most bound cluster. Most of the mass accreted
by the massive stars was originally distributed throughout the clump at low
densities, and was later funneled to the star due to global in-fall. Even with
radiative feedback no massive pre-stellar cores are formed. The original cores
are of intermediate mass and gain their additional mass in the proto-stellar
stage. We also find that cores which form low mass stars exist within the
volume from which the high mass stars accrete, but are largely unaffected by
this process.
