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 $M_{\mathrm{sub}}/M_{\mathrm{star}}=4.43_{-2.23}^{+6.63}$ at $r_p\in [0.1,0.3]$ $h^{-1}Mpc$ to $M_{\mathrm{sub}}/M_{\mathrm{star}}=75.40_{-19.09}^{+19.73}$ at $r_p\in [0.6,0.9]$ $h^{-1}Mpc$. We also investigate the dependence of subhalo masses on stellar mass by splitting satellite galaxies into two stellar mass bins: $10<\log (M_{\mathrm{star}}/M_{\mathrm{sun}})<10.5$ and $11<\log (M_{\mathrm{star}}/M_{\mathrm{sun}})<12$. The best-fit subhalo mass of the more massive satellite galaxy bin is larger than that of the less massive satellites: $\log (M_{\mathrm{sub}}/M_{\mathrm{sun}})=11.14_{-0.73}^{+0.66}$ ($M_{\mathrm{sub}}/M_{\mathrm{star}}=19.5_{-17.9}^{+19.8}$) versus $\log (M_{\mathrm{sub}}/M_{\mathrm{sun}})=12.38_{-0.16}^{+0.16}$ ($M_{\mathrm{sub}}/M_{\mathrm{star}}=21.1_{-7.7}^{+7.4}$).

10 pages, 8 figures, accepted by MNRAS