Shifts (top) and widths (bottom) of the iron features measure on γ Cas XRISM spectra. Fluorescence lines are shown as black dots, ionised lines with green stars. As in Table 1, the error bars are 1-σ uncertainties. In the top panel, all velocities are relative to that at the first observing phase and are compared to the expected orbital motion of both the Be star and its white dwarf companion, demonstrating that the iron lines follow the white dwarf motion. For comparison, small violet points indicate velocities measured on the Hα line, which is typically associated with the Be disc, at the time of the X-ray campaign (Nazé et al. 2025).