Galaxy Rotation Curves 2D — Dark Matter Evidence

Top-down galaxy disk + rotation-curve graph: visible-mass-only Keplerian decline vs the flat observed curve that dark matter explains.

Galaxy (top-down)

Rotation curve v(r)

Stellar mass 1.0 ×10¹⁰ M☉

Dark matter fraction 0.85

Halo scale r_s 8 kpc

Disk scale length 3 kpc

v(r) at R_sel: — km/s Newtonian-only v: — km/s V_flat: — km/s Dark matter fraction: — Selected radius: — kpc (drag on graph)

Stellar disk Bulge Visible-mass-only (Keplerian) +Dark matter (observed, flat) Dark matter halo

Galaxy Rotation Curve (2D)