Predicted number of observable HVSs, N_HVS, in Gaia DR4 as a function of the IMF slope κ. Panels show results for different assumed central black hole masses in the Sgr dSph: M_BH = 10³M_⊙ (left), 5 × 10³M_⊙ (center), and 10⁴M_⊙ (right). Solid orange, dashed sky-blue, and dotted bluish-green lines correspond to ejection rates of η = 10⁻², 10⁻³, and 10⁻⁴yr⁻¹, respectively. Shaded regions indicate the 16th-84th percentile range from bootstrap resampling.