2016MNRAS.458..379C

We present the stellar mass-halo mass scaling relation for 46 X-ray-selected low-mass clusters or groups detected in the XMM-Newton-Blanco Cosmology Survey (XMM-BCS) survey with masses 2 x 10¹³ M_☉ <= M₅₀₀ <= 2.5 x 10¹⁴ M_☉ (median mass 8 x 10¹³ M_☉) at redshift 0.1 <= z <= 1.02 (median redshift 0.47). The cluster binding masses M₅₀₀ are inferred from the measured X-ray luminosities L_X, while the stellar masses M_* of the galaxy populations are estimated using near-infrared (NIR) imaging from the South Pole Telescope Deep Field survey and optical imaging from the BCS survey. With the measured L_X and stellar mass M_*, we determine the best-fitting stellar mass-halo mass relation, accounting for selection effects, measurement uncertainties and the intrinsic scatter in the scaling relation. The resulting mass trend is , the intrinsic (lognormal) scatter is , and there is no significant redshift trend M_* ∝ (1 + z)^{–0.04±0.47}, although the uncertainties are still large. We also examine M_* within a fixed projected radius of 0.5 Mpc, showing that it provides a cluster binding mass proxy with intrinsic scatter of ≃93 per cent (1σ in M₅₀₀). We compare our M_*=M_*(M₅₀₀, z) scaling relation from the XMM-BCS clusters with samples of massive, Sunyaev-Zel'dovich Effect selected clusters (M₅₀₀ ≃ 6 x 10¹⁴ M_☉) and low-mass NIR-selected clusters (M₅₀₀ ≃ 10¹⁴ M_☉) at redshift 0.6 <= z <= 1.3. After correcting for the known mass measurement systematics in the compared samples, we find that the scaling relation is in good agreement with the high-redshift samples, suggesting that for both groups and clusters the stellar content of the galaxy populations within R₅₀₀ depends strongly on mass but only weakly on redshift out to z ≃ 1.