J-PLUS: Analysis of the intracluster light in the Coma cluster

Abstract

Context. The intracluster light (ICL) is a luminous component of galaxy clusters composed of stars that are gravitationally bound to the cluster potential, but do not belong to the individual galaxies. Previous studies of the ICL have shown that its formation and evolution are intimately linked to the evolutionary stage of the cluster. Thus, the analysis of the ICL in the Coma cluster will give insights into the main processes driving the dynamics in this highly complex system. Aims. Using a recently developed technique, we measure the ICL fraction in Coma at several wavelengths, using the J-PLUS unique filter system. The combination of narrow- and broadband filters provides valuable information on the dynamical state of the cluster, the ICL stellar types, and the morphology of the diffuse light. Methods. We used the Chebyshev-Fourier intracluster light estimator (CICLE) to distinguish the ICL from the light of the galaxies, and to robustly measure the ICL fraction in seven J-PLUS filters. Results. We obtain the ICL fraction distribution of the Coma cluster at different optical wavelengths, which varies from ∼7%-21%, showing the highest values in the narrowband filters J0395, J0410, and J0430. This ICL fraction excess is a distinctive pattern that has recently been observed in dynamically active clusters (mergers), indicating a higher amount of bluer stars in the ICL than in cluster galaxies. Conclusions. The high ICL fractions and the excess in the bluer filters are indicative of a merging state. The presence of younger stars or stars with lower metallicity in the ICL suggests that the main mechanism of ICL formation for the Coma cluster is the stripping of the stars in the outskirts of infalling galaxies and possibly the disruption of dwarf galaxies during past or ongoing mergers.© ESO 2019. ; Y. J-T. also acknowledges financial support from the Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro - FAPERJ (fellowship Nota 10, PDR-10) through grant E-26/202.835/2016. R.A.D. acknowledges support from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - CNPq through BP grant 312307/2015-2, and the Financiadora de Estudos e Projetos - FINEP grants REF. 1217/13 -01.13.0279.00 and REF 0859/10 - 01.10.0663.00 for hardware support for the J-PLUS project through the National Observatory of Brazil and CBPF. Both Y. J-T. and R.A.D. also acknowledge support from the Spanish National Research Council -CSIC (I-COOP+ 2016 program) through grant COOPB20263, and the Spanish Ministry of Economy, Industry, and Competitiveness -MINECO through grants AYA2013-48623-C2-1-P and AYA2016-81065-C2-1-P. R.L.O. was partially supported by the Brazilian agency CNPq (PDE 200289/2017-9, Universal Grants 459553/2014-3, PQ 302037/2015-2). J. A. H. J. thanks the Brazilian institution CNPq for financial support through a postdoctoral fellowship (project 150237/2017-0). Funding for the J-PLUS Project has been provided by the Governments of Spain and Aragon through the Fondo de Inversiones de Teruel, the Spanish Ministry of Economy and Competitiveness (MINECO; under grants AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, and ICTS-2009-14), and European FEDER funding (FCDD10-4E-867, FCDD13-4E-2685). ; Peer Reviewed