|
Context
| Today’s
Universe is composed of 73% dark energy, 23% dark matter, and 4%
baryonic matter. Incredibly, the mean density of the baryonic matter is
only 15% of the total density of the Universe, and it is only visible
to our eyes because a very small fraction of this matter has collapsed
into the dark matter potential wells and started to shine via the
nuclear reactions at the centres of stars. In this context, galaxy
clusters trace the large-scale distribution of matter in the Universe,
and are interesting for two principal reasons. Firstly, their large
masses and deep potential wells make them important astrophysical
laboratories in which we can follow the simultaneous evolution of the
principal components of the matter content in the Universe (dark and
baryonic). Secondly, as the peaks of the matter density field, the
formation and evolution of the cluster population are intimately linked
to the underlying cosmology. Clusters are thus privileged sites in
which to investigate the complex physics of structure formation;
equally, the evolution of the cluster population can give insights into
cosmology. |
Bibliography
- Arnaud, M., 2005,
http://arxiv.org/abs/astro-ph/0508159
- Böhringer & Werner,
2009, http://arxiv.org/abs/0907.4277
- Voit, 2005,
http://arxiv.org/abs/astro-ph/0410173
Gabriel
W. Pratt is a member of the Cosmology and Galaxy Evolution Laboratory
at the Service d’Astrophysique, CEA Saclay. His research interests
include multi-wavelength studies of galaxy clusters and eclipsing
binary stars. He has extensive experience of X-ray observations using
XMM-Newton, Chandra and ROSAT, and was a Planck HFI Core Team member
and Planck Scientist until 2014. He is heavily involved in ESA’s
next-generation X-ray observatory Athena, to be launched in 2028, and
is the point of contact within France for Athena science-related
issues. |
