Intracluster light properties in the CLASH-VLT cluster MACS J1206.2-0847

Aims: We aim constrain the assembly history of clusters by studying the intracluster light (ICL) properties, estimating its contribution to the fraction of baryons in stars, f*, and understanding possible systematics or bias using different ICL detection techniques. Methods: We developed an automated method, GALtoICL, based on the software GALAPAGOS, to obtain a refined version of typical BCG+ICL maps. We applied this method to our test case MACS J1206.2-0847, a massive cluster located at z ~ 0.44, which is part of the CLASH sample. Using deep multiband Subaru images, we extracted the surface brightness (SB) profile of the BCG+ICL and studied the ICL morphology, color, and contribution to f* out to R500. We repeated the same analysis using a different definition of the ICL, SBlimit method, i.e., a SB cut-off level, to compare the results. Results: The most peculiar feature of the ICL in MACS1206 is its asymmetric radial distribution, with an excess in the SE direction and extending toward the second brightest cluster galaxy, which is a post starburst galaxy. This suggests an interaction between the BCG and this galaxy that dates back to tau 0.3. At completion, the CLASH/VLT program will allow us to extend this analysis to a statistically significant cluster sample spanning a wide redshift range: 0.2 72 z 72 0.6