Scatterplots of o-H₂D⁺ molecular abundance with respect to H₂ column density in AG351 (blue, top panels) and AG354 (red, bottom panels). In the left panels, the quantities are computed assuming a constant temperature of 10 K. In the right panels, we use pixel-per-pixel the temperature derived from the o- H₂D⁺(1_1,0−1_1,1) line width, in the hypothesis of only thermal contributions. Scatterplot ranges are fixed to allow an easier comparison.For the sake of readability, we only show data points for which the relative 95% confidence interval is < 50%. The dashed black curve shows the correlation found by Sabatini et al. (2020). The black stars show the average values referring to the H₂D⁺-identified cores, for which significant continuum flux is detected. The N_col values to compute X_mol(o-H₂D⁺) are taken from Table 2, and the N(H₂) values are computed as averages in each core.