Galaxy and hot gas distributions in the z = 0.52 galaxy cluster RBS 380 from CHANDRA and NTT observations
1
Institute für Physik, Universität Potsdam, Am Neuen Palais 10, 14469 Potsdam, Germany
2
Institut für Astrophysik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria e-mail: Sabine.Schindler@uibk.ac.at
Corresponding author: R. Gil-Merino, rmerino@astro.physik.uni-potsdam.de
Received:
19
May
2003
Accepted:
17
June
2003
We present CHANDRA X-ray and NTT optical observations of
the distant 
galaxy cluster RBS 380 – the most distant
cluster of the ROSAT Bright Source (RBS) catalogue.
We find diffuse, non-spherically symmetric X-ray emission with
a X-ray luminosity of 
erg/s,
which is lower than expected from the RBS. The reason is a bright AGN in the centre of the cluster contributing considerably to the
X-ray flux. This AGN could not be resolved with ROSAT.
In optical wavelength we identify several galaxies belonging to the cluster.
The galaxy density is at least 2 times higher than expected for such a
X-ray faint cluster, which is another confirmation of the weak
correlation between X-ray luminosity and optical richness. The
example of the source confusion in this cluster shows how
important high-resolution X-ray imaging is for cosmological research.
Key words: galaxies: clusters: general / intergalactic medium / cosmology: observations / cosmology: theory / dark matter / X-rays: galaxies
© ESO, 2003