DARK MATTER HALO

NFW profile · rotation curve (flat vs Keplerian) · mass function · subhalo distribution
NFW Profile

ρ(r) = ρ_s / [(r/r_s)(1+r/r_s)²]

r_s = r_200/c

v_200 ≈ - km/s
r_200 ≈ - kpc
r_s = - kpc

Flat rotation curve:
V(r) ≈ const for r > r_s

Keplerian fall-off if
only baryons: V ∝ r^(-½)