Issue |
A&A
Volume 483, Number 3, June I 2008
|
|
---|---|---|
Page(s) | 727 - 739 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:200809400 | |
Published online | 26 March 2008 |
Diffuse stellar emission in X-ray luminous galaxy clusters at z ~ 0.3
I. Is the diffuse optical light boosted and rejuvenated in merging clusters?
1
Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching bei München, Germany e-mail: [dpierini;fbraglia;hxb;alexis]@mpe.mpg.de
2
Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany e-mail: zibetti@mpia-hd.mpg.de
3
ESO, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany e-mail: plynam@eso.org
4
Argelander-Institut für Astronomie, Rheinische Friedrich-Wilhelms-Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: yyzhang@astro.uni-bonn.de
Received:
15
January
2008
Accepted:
19
March
2008
Context. Clusters of galaxies host a diffuse population of intergalactic stars.
Diffuse optical light is observed in clusters up to redshift .
Recent cosmological hydrodynamical simulations show that
this intracluster light originates nearly in parallel
with the build-up of the brightest cluster galaxy (BCG),
as identified at
.
However, theory proposes alternative scenarios for its origin.
Aims. We searched for diffuse stellar emission around BCGs
in three of the most X-ray luminous clusters found at
in the REFLEX cluster survey and observed with XMM-Newton .
These systems (RXC J0014.3-3022, RXC J0232.2-4420,
and RXC J2308.3-0211) are in different dynamical states,
as witnessed by their X-ray morphology and optical appearence
(e.g. multiplicity of BCGs).
Methods. Existing medium-deep, wide-field imaging in B and R bands allows extension, intensity, and colour of the stellar emission to be determined across a region that encompasses the X-ray emission from the intracluster medium (ICM) in each cluster.
Results. Diffuse stellar emission is robustly detected
down to a surface brightness of 26 R- (observed frame)
around a total of seven BCGs, extending up to galactocentric distances
of ~
.
In particular, it surrounds a pair of BCGs in RXC J0232.2-4420,
while it bridges two BCGs associated with the minor subcomponent
of the merging cluster RXC J0014.3-3022.
The diffuse light detected at the greatest distances from the BCGs
of the rather regular clusters RXC J0232.2-4420 and RXC J2308.3-0211
follows the ICM distribution.
Its
colour is consistent
with the colours measured within the BCG effective radii.
The diffuse light around the two pairs of BCGs in RXC J0014.3-3022
exhibits bluer colours than the BCG central regions by up to 0.5 mag.
Conclusions. If the contribution of the intracluster light (ICL)
to the detected diffuse light around BCGs is not negligible, ICL and BCGs
have similar stellar populations in relatively relaxed clusters.
Merging on a cluster scale eventually adds gravitational stresses
to BCGs and other galaxies in subcluster cores.
This event may affect the properties of the diffuse stellar emission
around BCGs.
Shredding of star-forming, low-metallicity dwarf galaxies
is favoured as the cause of the bluer colours
of the diffuse stellar component around the two pairs of BCGs
in the merging cluster RXC J0014.3-3022.
Key words: X-rays: galaxies: clusters / galaxies: clusters: general / galaxies: elliptical and lenticular, cD / galaxies: evolution / galaxies: interactions / diffuse radiation
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.