Thursday

The famous Rosette Nebula has a central cavity formed from the stellar winds ejected from the 2-6 million-year-old central star cluster NGC 2244. However, with an estimated age of only ~100,000 years, the central cavity is too young compared to NGC 2244 and simple shell models do not reproduce its properties. Here, we present a new ring-like structure for the Rosette Nebula that resolves this discrepancy, through 3D MHD simulation of massive star stellar feedback in a sheet-like molecular cloud that appears filamentary in projection. The cloud has been formed through the action of the thermal instability, with self-gravity and magnetic fields (MNRAS 459, 1803-1818, 2016). The wind from a 60 solar mass star, following a Geneva evolutionary model, has carved out the central cavity and escaped the cloud along the magnetic field axis. Observationally-derived physical properties, such as size, column density, the location of triggered star formation and magnetic field configuration, compare very well to the model and a revealing new proper motion study of NGC 2244 using Gaia data also provides strong support. We conclude with a brief review of our wider suite of simulations considering the mechanical stellar feedback impact upon the cloud and surrounding ISM of both wind and supernova of stars ranging from 15 to 120 solar masses, on both this sheet-like cloud and also the hydrodynamic case of a clumpy spherical cloud, formed also by the action of the thermal instability.