The XXL Survey VIII. MUSE characterisation of intracluster light in a z similar to 0.53 cluster of galaxies
Artikel i vetenskaplig tidskrift, 2016

Aims. Within a cluster, gravitational effects can lead to the removal of stars from their parent galaxies and their subsequent dispersal into the intracluster medium. Gas hydrodynamical effects can additionally strip gas and dust from galaxies; both gas and stars contribute to intracluster light (ICL). The properties of the ICL can therefore help constrain the physical processes at work in clusters by serving as a fossil record of the interaction history. Methods. The present study is designed to characterise this ICL for the first time in a similar to 10(14) M-circle dot and z similar to 0.53 cluster of galaxies from imaging and spectroscopic points of view. By applying a wavelet-based method to CFHT Megacam and WIRCAM images, we detect significant quantities of diffuse light and are able to constrain their spectral energy distributions. These sources were then spectroscopically characterised with ESO Multi Unit Spectroscopic Explorer (MUSE) spectroscopic data. MUSE data were also used to compute redshifts of 24 cluster galaxies and search for cluster substructures. Results. An atypically large amount of ICL, equivalent in i' to the emission from two brightest cluster galaxies, has been detected in this cluster. Part of the detected diffuse light has a very weak optical stellar component and apparently consists mainly of gas emission, while other diffuse light sources are clearly dominated by old stars. Furthermore, emission lines were detected in several places of diffuse light. Our spectral analysis shows that this emission likely originates from low-excitation parameter gas. Globally, the stellar contribution to the ICL is about 2.3 x 10(9) yr old even though the ICL is not currently forming a large number of stars. On the other hand, the contribution of the gas emission to the ICL in the optical is much greater than the stellar contribution in some regions, but the gas density is likely too low to form stars. These observations favour ram pressure stripping, turbulent viscous stripping, or supernovae winds as the origin of the large amount of intracluster light. Since the cluster appears not to be in a major merging phase, we conclude that ram pressure stripping is the most plausible process that generates the observed ICL sources. Conclusions. This is one of the first times that we are able to spectroscopically study diffuse light in such a distant and massive cluster, and it demonstrates the potential of MUSE observations for such studies.

STAR-FORMATION

ABUNDANCES

galaxies: clusters: intracluster medium

WIDE FIELDS

EVOLUTION

STELLAR

X-RAY-CLUSTERS

DIFFUSE LIGHT

Astronomy & Astrophysics

MORPHOLOGY

galaxies: clusters: general

DWARF GALAXIES

PHOTOMETRIC REDSHIFTS

Författare

C. Adami

Laboratoire d'Astrophysique de Marseille

E. Pompei

European Southern Observatory Santiago

T. Sadibekova

Le Commissariat à l’énergie atomique et aux énergies alternatives (CEA)

N. Clerc

Max Planck-institutet

A. Iovino

Osservatorio Astronomico di Brera

Sean L. McGee

University of Birmingham

L. Guennou

Institut d'Astrophysique Spatiale

Laboratoire d'Astrophysique de Marseille

M. Birkinshaw

University of Bristol

Cathy Horellou

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

S. Maurogordato

Universite Nice Sophia Antipolis

F. Pacaud

Universität Bonn

M. Pierre

Le Commissariat à l’énergie atomique et aux énergies alternatives (CEA)

B. Poggianti

Osservatorio Astronomico di Padova

J. Willis

University of Victoria

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 592 A7

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

Infrastruktur

Onsala rymdobservatorium

DOI

10.1051/0004-6361/201526831