We present an investigation of the relationship between giant molecular cloud (GMC) properties and the associated stellar clusters in the nearby flocculent galaxy NGC 7793. We combine the star cluster catalog from the HST LEGUS (Legacy ExtraGalactic UV Survey) program with the 15 parsec resolution ALMA CO(2-1) observations. We find a strong spatial correlation between young star clusters and GMCs such that all clusters still associated with a GMC are younger than 11 Myr and display a median age of 2 Myr. The age distribution increases gradually as the cluster-GMC distance increases, with star clusters that are spatially unassociated with molecular gas exhibiting a median age of 7 Myr. Thus, star clusters are able to emerge from their natal clouds long before the timescale required for clouds to disperse. To investigate if the hierarchy observed in the stellar components is inherited from the GMCs, we quantify the amount of clustering in the spatial distributions of the components and find that the star clusters have a fractal dimension slope of −0.35 ± 0.03, significantly more clustered than the molecular cloud hierarchy with slope of −0.18 ± 0.04 over the range 40-800 pc. We find, however, that the spatial clustering becomes comparable in strength for GMCs and star clusters with slopes of −0.44 ± 0.03 and −0.45 ± 0.06 respectively, when we compare massive (>10 5 M ) GMCs to massive and young star clusters. This shows that massive star clusters trace the same hierarchy as their parent GMCs, under the assumption that the star formation efficiency is a few percent.

Dense molecular gas and star formation are correlated in galaxies. The effect of low metallicity on this relationship is crucial for interpreting observations of high redshift galaxies, which have lower metallicities than galaxies today. However, it remains relatively unexplored because dense molecular gas tracers like HCN and HCO + are faint in low metallicity systems. We present Green Bank Telescope observations of HCN(1-0) and HCO + (1-0) on giant molecular cloud (34 pc) scales in the nearby low metallicity (12 + log(O/H) = 8.2) starburst IC 10 and compare them to those in other galaxies. We detect HCN and HCO + in one and three of five pointings, respectively. The I HCN /I HCO + values are within the range seen in other galaxies, but are most similar to those seen in other low metallicity sources and in starbursts. The detections follow the fiducial L IR -L HCN and L IR -L HCO + relationships. These trends suggest that HCN and HCO + can be used to trace dense molecular gas at metallicities of 1/4 Z , to first order. The dense gas fraction is similar to that in spiral galaxies, but lower than that in U/LIRGs. The dense molecular gas star formation efficiency, however, is on the upper end of those in normal galaxies and consistent with those in U/LIRGs. These results suggest that the CO and HCN/HCO + emission occupy the same relative volumes as at higher metallicity, but that the entire emitting structure is reduced in size. Dense gas mass estimates for high redshift galaxies may need to be corrected for this effect.