Histograms of neutral, neutral atomic (H I), and molecular (H₂) gas masses for the AGN (orange) and non-AGN control (blue) samples. The upper panel shows the bound neutral gas masses, with the solid line indicating the total amount and the dashed line indicating only the mass within 2R_e, *. The middle and lower panels show the total bound gas masses in the form of H I and H₂, taken from the TNG supplementary catalog (Diemer et al. 2019). Each line style of the histograms refers to a type of partition model considered by Diemer et al. (2019) in their post-processing: solid lines are from Gnedin & Draine (2014), dashed lines are from Gnedin & Draine (2014), dotted lines are from Krumholz (2013), and dotted-dashed lines are from Sternberg et al. (2014). Here, we show different models to illustrate variations in the values of M_H I and M_H2. In the upper right of each panel, we show the average pair-wise differences (Δ_pair) between the AGN and non-AGN logarithmic masses. The samples being compared here are 𝒮_{M* & M200c}^WG and 𝒞_{M* & M200c}^WG.