finds the CO (2–1) emission confined to the central 1-1.5 of these galaxies. Both the CO (2–1) sizes and Spitzer IRAC 8$\mu$m sizes are smaller than the optical sizes. The optical $r$-band half-light radii of these galaxies is 1.71 and 2.74 for H02 and S05, respectively. The resolved CO (2–1) fluxes are consistent with the unresolved IRAM 30m CO (2–1) observations (with $\sim$11 beamsize), indicating a lack of significant CO emitting gas beyond the central 1-2 kpc of these galaxies. Thus, it is unlikely that significant HCN emission is resolved out by our observations, as HCN emission is unlikely to be found outside of the CO emitting regions.

Additionally, interferometric observations typically constrain HCN emission to come from the central kpc of galaxies [e.g., @Aalto2012; @Kepley2013; @Scoville2015; @Chen2015]. Even when this dense gas is more extended or in outflows [e.g., @Alatalo2014; @Salas2014], the HCN emission does not extend more than 500 pc from the main disk. The ALMA HCN observations can therefore be directly compared to the single dish CO (1–0) measurements.

The observations of H02 were executed in one block on November 4, 2016. The observations of S05 were executed in four blocks on November 22 and 25, 2016, 