The fraction of stars in clusters (Γ) versus ΣSFR for the LEGUS dwarf galaxies. Similar to Fig. 7, the top panels represent results based on integrated-light SFRs, and the bottom panels represent results from SFRs based on the resolved stellar populations (stars+clusters). The ages of the cluster populations used to derive Γ have been separated for clarity. From left-to-right: red, blue, and green symbols represent results for 1–10, 1–100, and 10–100 Myr clusters, respectively. The smaller symbols represent cluster populations in individual galaxies, while the larger, semi-transparent symbols represent composite clusters binned by ΣSFR. The grey points represent literature values separated into the appropriate age ranges and are tabulated in Appendix B. The median Γ measurements for the individual galaxies (and binned by ΣSFR) studied here are presented in the upper right-hand corners of each panel. The horizontal dotted line represents an arbitrary Γ value where galaxies and bins with no clusters are plotted. The dashed–dot and dashed lines are theoretical predictions derived by Kruijssen (2012) when using the global (Kennicutt & Evans 2012) and sub-kpc (Bigiel et al. 2008) conversion between Σgas and ΣSFR, and have been commonly used to provide a comparison to models that predict a dependence of Γ on environment (see further discussion in Section 6.1). The shaded regions represent the age-dependent models of Dinnbier, Kroupa & Anderson (2022) and have been placed in the appropriate panels. The vertical numbers at the bottom of each panel represent the number of galaxies (and clusters) in each ΣSFR bin.
