When: Friday, October 29, 2021, 2:30 PM - 3:30 PMWhere: Physics (G. O. Jones building) room 610 & online
Speaker: Clare Dobbs (Exeter)
Cluster formation in spiral galaxies and the role of feedback
Many simulations have examined the formation of stellar clusters in isolated giant molecular clouds (GMCs). Here we attempt to look at the formation of stellar clusters in the context of galactic environment. We first discuss the role of cloud-cloud collisions and converging flows, showing that only in more extreme cases do we expect to find that cloud cloud collisions enhance star formation compared to gravity alone. We then examine converging flows in galactic spiral arms, and find that with stronger converging flows, or equivalently more negative divergence, more massive clusters occur, growing both through accretion and because mergers between clusters are more common in such environments. We also look at the role of photoionisation in our simulations. Ionisation typically limits the mass of the clusters by 20 plus minus 10 %, but still allows the formation of massive clusters in our models. Ionisation has a strong impact on the surrounding gas in the cluster, clearing out around 80% of the gas in the vicinity of the clusters over 1-2 Myr. Similar to previous work in the field, supernovae and winds appear to have less of an impact in our simulations compared to photoionisation. Finally, whilst most of the results we show use sink particles to represent subclusters of stars, we also briefly introduce the Ekster code (from AMUSE) which allows the full N-body dynamics of star clusters to be modelled and resolved, even if the hydrodynamical resolution is not correspondingly high.