Intra-Cluster Light at the Frontier: Abell 2744

Understand

The ultra-deep multiwavelength HST Frontier Fields coverage of the Abell Cluster 2744 is used to derive the stellar population properties of its intra-cluster light (ICL).

• The restframe colors of the ICL of this intermediate redshift (z=0.3064) massive cluster are bluer (g-r=0.68+-0.04; i-J=0.56+-0.01) than those found in the stellar populations of its main galaxy members (g-r=0.83+-0.01; i-J=0.75+-0.01).
• Based on these colors, we derive the following mean metallicity Z=0.018+-0.007 for the ICL.
• The ICL age is 6+-3 Gyr younger than the average age of the most massive galaxies of the cluster.