J-PLUS: Analysis of the intracluster light in the Coma cluster
Observatório Nacional, Rua General José Cristino, 77 – Bairro Imperial de São Cristóvão, Rio de Janeiro, 20921-400, Brazil
2 Instituto de Astrofísica de Andalucía, Glorieta de la Astronomía s/n, 18008 Granada, Spain
3 Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487, USA
4 Department of Astronomy, University of Michigan, 311 West Hall, 1085 South University Ave., Ann Arbor, MI 48109-1107, USA
5 X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
6 Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
7 Departamento de Física, Universidade Federal de Sergipe, Av. Marechal Rondon s/n, 49000-000 São Cristóvão, SE, Brazil
8 Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Rua do Matão 1226, C. Universitária, São Paulo 05508-090, Brazil
9 Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
10 Centro de Estudios de Física del Cosmos de Aragón, Unidad Asociada al CSIC, Plaza San Juan 1, 44001 Teruel, Spain
Accepted: 28 September 2018
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.
Key words: galaxies: clusters: individual: Coma / techniques: image processing
© ESO 2019