Galactic multiscale simulations of cloud and star cluster formation

Ralph Pudritz

Tuesday, Dec. 6th, 11:50CET

Most existing numerical studies of giant molecular cloud (GMC) and star cluster formation are carried out in an isolated fashion that is disconnected from the host galactic environment. Although such a set-up has shed light on many fundamental questions in massive star formation, it ignores the important effects of large-scale gas flows driven by stellar feedback and galactic shear. To circumvent such limitations, we carry out MHD simulations adopting a novel zoom-in technique that follows the evolution of a typical 3-kpc region without cutting out the surrounding galactic environment. This allows us to reach 0.28 pc resolution in the individual zoom-in regions and follow the formation and early evolution of GMCs from the galactic disk down to cluster scales. We find that the condensations of GMCs show a wide-range of morphologies and are highly hierarchical. Some GMCs can condense by gravitational instability of large-scale (kpc) filamentary structures created large scale bubbles driven by stellar feedback. Galactic shear produces produces GMC complexes that become flattened, disk-like structures with 50–100 pc extended spiral structures within which multiple GMC condensations arise. Notably, magnetic field topologies associated with such disk structures are highly helical. We address how these processes impact the origin of cluster forming regions within GMCs.