Do satellite galaxies trace matter in galaxy clusters?
  The spatial distribution of satellite galaxies encodes rich information of
the structure and assembly history of galaxy clusters. In this paper, we select
a redMaPPer cluster sample in SDSS Stripe 82 region with $0.1 \le z \le 0.33$,
$20<\lambda<100$ and $P_{\rm cen}>0.7$. Using the high-quality weak lensing
data from CS82 Survey, we constrain the mass profile of this sample. Then we
compare directly the mass density profile with the satellite number density
profile. We find that the total mass and number density profiles have the same
shape, both well fitted by an NFW profile. The scale radii agree with each
other within 1$\sigma$ error ($r_{\rm s,gal}=0.34_{-0.03}^{+0.04}$Mpc vs
$r_{\rm s}=0.37_{-0.10}^{+0.15}$Mpc ).
