Σ_SFR against Σ_H2 for the HATLAS114625 (left) and HATLAS121446 (right) starbursts. In each panel, the errorbar in the bottom-right corner represents the typical 1-σ uncertainty. The arrow indicates the horizontal shift of the data produced if we assume the α_CO, uplim value instead of the median α_CO estimate to calculate Σ_H2. This is also highlighted by the lightly coloured data showed in the background. The dotted lines indicate fixed τ_dep values. We show ∼kpc-scale spatially resolved observations of two z ∼ 0 LIRGs (orange diamonds, Espada et al. 2018) and the median trend observed for the nearby HERACLES galaxy survey (open circles, Leroy et al. 2013). The dot-dashed line represents the best fit for the HERACLES ∼kpc-scale median values. We also present spatially resolved estimates for local ULIRGs measured at ∼350−650 pc scales (Wilson et al. 2019). In solid and dashed lines, we show the double and single power-law best fits reported by Wilson et al. (2019) for the ULIRG data, respectively. Independent of the α_CO value assumed, we find lower τ_dep values than those measured from local normal SFGs.