Cluster Formation and Destruction in Infrared Galaxies

22 October 2021

Most stars form in clusters, making the formation and fate of star clusters an important component of the evolution of galaxies. The elevated star formation rates of interacting and merging galaxies mean that they should be forming more clusters than non-interacting galaxies. It is also expected that the chaotic nature of galaxy mergers may increase the rate at which star clusters are destroyed (with the member stars diffusing into the larger stellar population of the galaxy). In “Massive Star Cluster Formation and Destruction in Luminous Infrared Galaxies in GOALS II: An ACS/WFC3 Survey of Nearby LIRGs” (Linden+) we explored the cluster population of ten infrared-selected galaxies. For a subset of the closer systems we identified over one thousand star clusters. We find that there are differences in the cluster age distributions between the inner and outer regions of the galaxies; we link this to mass-dependent cluster disruption in the galaxy centers. Additionally, we find that galaxies at later merger stages have a flatter cluster mass function (i.e., an excess of massive clusters) relative to those galaxies at earlier merger stages.

The paper has been accepted for publication in The Astrophysical Journal and a preprint is available.