Relation between the Mg II and [O II] spatial extent and offset measured for our sample. Top left (right): Mg II ([O II]) exponential scale length plotted as a function of the Mg II ([O II]) spatial offset relative to the continuum. Bottom left (middle): Ratio between the Mg II ([O II]) and continuum scale length versus the Mg II ([O II]) spatial offset relative to the continuum. Bottom right: Ratio between the Mg II and [O II] scale length versus the Mg II spatial offset relative to the [O II] emission. The Kendall correlation coefficient (τ) and the corresponding probability that the correlation is real (p) are given and colored in green if the correlation is statistically significant (Akritas & Siebert 1996; Flury et al. 2022b, see Sect. 3.4). Objects with statistically significant Mg II and [O II] extended emission are indicated by large purple and green symbols, respectively (Sect. 3.4).