Back to Search
Start Over
The relation between mass and concentration in X-ray galaxy clusters at high redshift
- Publication Year :
- 2016
-
Abstract
- Galaxy clusters are the most recent, gravitationally-bound products of the hierarchical mass accretion over cosmological scales. How the mass is concentrated is predicted to correlate with the total mass in the cluster's halo, with systems at higher mass being less concentrated at given redshift and for any given mass, systems with lower concentration are found at higher redshifts. Through a spatial and spectral X-ray analysis, we reconstruct the total mass profile of 47 galaxy clusters observed with Chandra in the redshift range $0.40.4$, and is well suited to provide the first constraint on the concentration--mass relation at $z>0.7$ from X-ray analysis. Under the assumptions that the distribution of the X-ray emitting gas is spherically symmetric and in hydrostatic equilibrium, we combine the deprojected gas density and spectral temperature profiles through the hydrostatic equilibrium equation to recover the parameters that describe a NFW total mass distribution. The comparison with results from weak lensing analysis reveals a very good agreement both for masses and concentrations. Uncertainties are however too large to make any robust conclusion on the hydrostatic bias of these systems. The relation is well described by the form $c \propto M^B (1+z)^C$, with $B=-0.50 \pm 0.20$, $C=0.12 \pm 0.61$ (at 68.3\% confidence), it is slightly steeper than the one predicted by numerical simulations ($B\sim-0.1$) and does not show any evident redshift evolution. We obtain the first constraints on the properties of the concentration--mass relation at $z > 0.7$ from X-ray data, showing a reasonable good agreement with recent numerical predictions.<br />Comment: A&A accepted, 18 pages, 13 figures, 1 Appendix
- Subjects :
- Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Dark matter
FOS: Physical sciences
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
01 natural sciences
Cosmology: observation
law.invention
Gravitational potential
law
0103 physical sciences
010303 astronomy & astrophysics
Galaxy cluster
Astrophysics::Galaxy Astrophysics
Intergalactic medium
Physics
Mass distribution
010308 nuclear & particles physics
Astronomy and Astrophysics
Astronomy and Astrophysic
Accretion (astrophysics)
Redshift
Space and Planetary Science
Halo
Galaxies: clusters: general
Hydrostatic equilibrium
X-rays: galaxie
Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....900b13ec8f9cd0a213cb7be9f8dc47bd