= Low-angular-momentum baryonic disk estimate
{title2=$r_d\simeq j_d^2/(GM_b)$}
Selecting a baryonic mass $M_b$ from a normalized cumulative distribution $M_b(<j)\propto j$ fixes a cutoff specific angular momentum $j_d=(M_b/M_{b,\rm tot})j_{\rm vir}$. With circular support and dominant enclosed baryonic gravity, the outer radius is $r_d\simeq j_d^2/(GM_b)$ and speed $v_d\simeq GM_b/j_d$. The mean specific angular momentum is $j_d/2$, which defines a different one-zone radius. The estimate assumes energy dissipation but negligible redistribution of <specific angular momentum>.
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