Room L269 (former D18, 2nd floor) at ENS, 24 rue Lhomond, 13:30 to 14:30

High mass stars dominate the energy injection into the interstellar medium and eventually explode as supernovae, producing most of the heavy elements in the universe.  Feedback processes from massive stars plays a critical role in their formation, destroys the molecular clouds in which they are born and shape the evolution of galaxies.  In this talk I will discuss our recent 3D AMR simulations that are the first to include the coupled feedback effects of protostellar outflows combined with protostellar heating and radiation pressure feedback in a single computation on the infalling dusty gas in the surrounding environs of the accreting core envelope.  These simulations  will address  the detailed effects of feedback on massive star formation in a range of star forming environments, from typical galactic star forming conditions to conditions typical of  extragalactic super star clusters.  In a series of simulations with and without ouflow feedback, demonstrating the strong coupling between outflows and radiative feedback on the parent cloud,  I will show that outflows evacuate polar cavities to reduce optical depth through the ambient core which enhances the radiative flux in the poleward direction up to 15 times larger than in the mid-plane of the surrounding accretion disk.  As a result, the radiative heating and outward radiative force exerted on the protostellar disk and infalliing gas in the equatorial direction  are greatly diminished.  This  simultaneously reduces the Eddington radiation  pressure  barrier to high mass star formation and increases the minimum threshold surface density for radiative heating to suppress fragmentation and allow high mass star formation compared to models that  do not include outflows.  It will be shown that higher surface density clouds exhibit enhanced radiative feedback, diminished disk fragmentation  and host more massive primary stars with less massive companions, however the effects of protostellar outflow feedback diminish with increased surface density.  Conversely, protostellar cores in lower surface density clouds undergo more rapid Kelvin contraction relative to the dynamical time of the cloud, leading to more powerful outflows and more effective mechanical feedback.  A key result is that radiation focusing in the direction of the outflow cavities is sufficient to prevent the formation of radiation-driven Rayleigh-Taylor unstable bubbles in contrast to models that neglect protostellar outflow feedback.   Finally, I will present the first results on the effects of magnetic fields fully coupled with outflow and radiative feedback in high mass stars in a turbulent cloud using our new MHD development in ORION.