I_{CO(1 − 0)} versus I_MIRI770 (top), and I_MIRI1130 (bottom). Points in left panels are colored in the five regions we adopt to classify the clouds in M 82 (see Section 3.2). We also include the best-fit linear relations we obtain for the whole sample after binning the points in the x-axis and performing an ordinary least square (OLS) linear fitting using the model y = mx + b (black-dashed lines), and the Pearson’s r-value for the different regions in the right-bottom corners. Error bars correspond to the scatter of the points in the y-axis for the binned data. The left panels show the same relations that those in right ones, but colorcoded by the size of clouds, where symbols are split in clouds larger (circles) and shorter (stars) than 100 pc.