Baryon conversion efficiency of a halo
= Baryon conversion efficiency of a halo
{title2=$f_*=M_*/(f_bM_h)$}
The <baryon conversion efficiency of a halo> is the fraction of its baryonic mass incorporated into stars. If the halo retains the <cosmic baryon fraction> $f_b$, its stellar-to-total-mass ratio is $f_bf_*$. This efficiency depends on halo mass, epoch, gas supply and feedback and must not be confused with a star-formation efficiency per free-fall time.