Left panel: density profiles for a generalized NFW halo (dashed lines) with γ = 1 and the same halo with a spike in the central region (solid lines) for a non-annihilating DM candidate (purple) and a self-annihilating 1 TeV DM candidate with ⟨σv⟩ ∼ 10⁻³⁰ cm³ s⁻¹, ⟨σv⟩ ∼ 10⁻²⁷ cm³ s⁻¹, and ⟨σv⟩ ∼ 10⁻²⁶ cm³ s⁻¹ (orange, blue, and red, respectively). Right panel: corresponding mass profiles, with the same line styles as in the left panel. The profiles are shown for illustration purposes for a spike radius R_sp ∼ 100 pc corresponding to the 99.7% upper limit from deviations of the BH-only orbit using the VLT data (see Sect. 3). The horizontal solid and dotted lines represent the combined 2009 and 2017 constraints, respectively. The vertical dot-dashed line marks the characteristic size of the orbit of S2.