Abstract

Contributed Talk - Splinter StarFormation

Feedback in NGC3603: warm but quiet!

Thomas Stanke
MPE

Feedback from the massive star population of freshly formed massive young clusters could be expected to have a significant impact on the dense gas physical properties surrounding these clusters and skew the stellar mass function resulting from star formation in such an environment. Higher temperatures may lead to a larger Jeans mass, while enhanced turbulence may favour fragmentation to smaller masses. We here explore to which extent feedback from the massive star population in the NGC3603 young massive cluster could potentially affect the outcome of further star formation in adjacent clouds due to heating and generation of turbulence in the dense gas forming the next generation of stars. We use APEX H2CO molecular line maps to measure the dense gas temperature distribution around the NGC3603 galactic young massive clusters. We find a clear gradient - temperature falling with distance over scales of several parsec, indicating that indeed feedback can have a profound impact on the dense gas temperature. To complicate the picture, however, we also find evidence for very cold (20K) gas even in the massive, 60K warm clumps directly exposed to the NGC3603 starburst cluster from N2H+ observations! This finding calls for a discussion on whether or not cold, dense gas or rather warm gas forms the next generation of stars in starburst environments, and whether this could have an effect on the resulting stellar initial mass function. We use H2CO and 13CO lines to search for trends in line widths/velocity dispersion with distance from the cluster. We find preferentially narrower lines near the cluster, indicating that turbulence is suppressed rather than enhanced by the feedback from the cluster.