Issue |
A&A
Volume 402, Number 1, April IV 2003
|
|
---|---|---|
Page(s) | 53 - 63 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20030197 | |
Published online | 07 April 2003 |
Observational constraints on general relativistic energy conditions, cosmic matter density and dark energy from X-ray clusters of galaxies and type-Ia supernovae
1
Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, 85740 Garching, Germany
2
Department of Physics & Astronomy, Dartmouth College, Hanover, NH 03755, USA
3
Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD, UK
4
INAF-Osservatorio di Brera, via Bianchi, 22055 Merate (LC), Italy
5
California Institute of Technology, Mail Code 130-33, Pasadena, CA 91125, USA
Corresponding author: P. Schuecker, peters@mpe.mpg.de
Received:
22
November
2002
Accepted:
6
February
2003
New observational constraints on the cosmic matter density and an effectively redshift-independent equation of state
parameter wx of the dark energy are obtained while simultaneously
testing the strong and null energy conditions of general relativity on
macroscopic scales. The combination of REFLEX X-ray cluster and
type-Ia supernova data shows that for a flat Universe the strong
energy condition might presently be violated whereas the null energy
condition seems to be fulfilled. This provides another observational
argument for the present accelerated cosmic expansion and the absence
of exotic physical phenomena related to a broken null energy
condition. The marginalization of the likelihood distributions is
performed in a manner to include a large fraction of the recently
discussed possible systematic errors involved in the application of
X-ray clusters as cosmological probes. This yields for a flat
Universe,
and
(
errors without cosmic
variance). The scatter in the different analyses indicates a quite
robust result around
, leaving little room for the
introduction of new energy components described by quintessence-like
models or phantom energy. The most natural interpretation of the data
is a positive cosmological constant with
or something like
it.
Key words: cosmology: cosmological parameters / X rays: galaxies: clusters
© ESO, 2003
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