Measuring subhalo mass in redMaPPer clusters with CFHT Stripe 82 Survey

Abstract: We use the shear catalog from the CFHT Stripe-82 Survey to measure the subhalo masses of satellite galaxies in redMaPPer clusters. Assuming a Chabrier Initial Mass Function (IMF) and a truncated NFW model for the subhalo mass distribution, we find that the sub-halo mass to galaxy stellar mass ratio increases as a function of projected halo-centric radius $r_p$, from $$M_{\rm sub}/M_{\rm star}=4.43^{+ 6.63}<em>{- 2.23}$$ at $r_p \in [0.1,0.3]$ $h<sup>{-1}Mpc$ to $$M</em>{\rm sub}/M_{\rm star}=75.40^{+ 19.73}<em>{- 19.09}$$ at $r_p \in [0.6,0.9]$ $h<sup>{-1}Mpc$. We also investigate the dependence of subhalo masses on stellar mass by splitting satellite galaxies into two stellar mass bins: $10&lt;\log(M</em>{\rm star}/M_{\rm sun})&lt;10.5$ and $11&lt;\log(M_{\rm star}/M_{\rm sun})&lt;12$. The best-fit subhalo mass of the more massive satellite galaxy bin is larger than that of the less massive satellites: $$\log(M_{\rm sub}/M_{\rm sun})=11.14 ^{+ 0.66 }<em>{- 0.73}$$ ($$M</em>{\rm sub}/M_{\rm star}=19.5<sup>{+19.8}_{-17.9}$$) versus $$\log(M_{\rm sub}/M_{\rm sun})=12.38 ^{+ 0.16 }<em>{- 0.16}$$ ($$M</em>{\rm sub}/M_{\rm star}=21.1<sup>{+7.4}_{-7.7}$$).