Size of the Mg II emission halos after correcting by self-absorption as described in Sec. 4. The left panel shows the sizes of the Mg II emission halos as a function of the stellar mass of each galaxy, derived via SED fitting. The inset in the left panel shows a zoom-in to the HLR versus stellar mass relation for only those galaxies with HLR < 8 kpc. The right panel shows the ratio between the size of the Mg II emission halos and the size of the stellar component, as a function of the stellar mass of our sample galaxies. The horizontal dashed gray line shows the ratio of one for reference.