J/A+A/674/A48 Planck-ESZ gas fraction sample (Wicker+, 2023)
Constraining the mass and redshift evolution of the hydrostatic mass bias using
the gas mass fraction in galaxy clusters.
Wicker R., Douspis M., Salvati L., Aghanim N.
<Astron. Astrophys. 674, A48 (2023)>
=2023A&A...674A..48W 2023A&A...674A..48W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources
Keywords: large-scale structure of Universe - cosmological parameters -
galaxies: clusters: general - methods: data analysis -
galaxies: clusters: intracluster medium - X-rays: galaxies: clusters
Abstract:
The gas mass fraction in galaxy clusters is a convenient probe to use
in cosmological studies, as it can help derive constraints on a range
of cosmological parameters.
This quantity is, however, subject to various effects from the
baryonic physics inside galaxy clusters, which may bias the obtained
cosmological constraints. Among different aspects of the baryonic
physics at work, in this paper we focus on the impact of the
hydrostatic equilibrium assumption.
We analyzed the hydrostatic mass bias B, constraining a possible
mass and redshift evolution for this quantity and its impact on the
cosmological constraints.
To that end, we considered cluster observations of the Planck-ESZ
sample and evaluated the gas mass fraction using X-ray counterpart
observations. We show a degeneracy between the redshift dependence of
the bias and cosmological parameters.
In particular we find evidence at 3.8σ for a redshift dependence
of the bias when assuming a Planck prior on Omegam. On the other
hand, assuming a constant mass bias would lead to the extremely large
value of Omegam>0.860. We show, however, that our results are
entirely dependent on the cluster sample under consideration. In
particular, the mass and redshift trends that we find for the lowest
mass-redshift and highest mass-redshift clusters of our sample are not
compatible. In addition, we show that assuming self-similarity in our
study can impact the results on the evolution of the bias, especially
with regard to the mass evolution. Nevertheless, in all the analyses,
we find a value for the amplitude of the bias that is consistent with
B∼0.8, as expected from hydrodynamical simulations and local
measurements. However, this result is still in tension with the low
value of B∼0.6 derived from the combination of cosmic microwave
background primary anisotropies with cluster number counts.
Description:
Gas masses and total masses obtained from XMM-Newton observations. Gas
fractions have been computed from these masses.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fgas-esz.dat 124 120 Planck-ESZ gas fraction sample
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See also:
VIII/88 : Planck early results. VIII. ESZ sample. (Planck+, 2011)
J/ApJ/892/102 : XMM X-ray data of Planck ESZ galaxy clusters (Lovisari+, 2020)
Byte-by-byte Description of file: fgas-esz.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Name in the Planck ESZ sample
22- 26 F5.3 --- z Redshift
28- 32 F5.3 10+14Msun Mgas Gas mass (1)
34- 38 F5.3 10+14Msun e_Mgas Lower uncertainty on gas mass (1)
40- 44 F5.3 10+14Msun E_Mgas Upper uncertainty on gas mass (1)
46- 50 F5.2 10+14Msun Mtot Total hydrostatic mass (1)
52- 55 F4.2 10+14Msun e_Mtot Lower uncertainty on total mass (1)
57- 60 F4.2 10+14Msun E_Mtot Upper uncertainty on total mass (1)
62- 81 F20.18 --- fgas Gas fraction
82-102 F21.19 --- e_fgas Lower uncertainty on gas fraction
104-124 F21.19 --- E_fgas Upper uncertainty on gas fraction
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Note (1): The gas masses and total masses have been derived in
Lovisari et al., 2020ApJ...892..102L 2020ApJ...892..102L, Cat. J/ApJ/892/102)
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Acknowledgements:
Raphael Wickers, raphael.wicker(at)ias.u-psud.fr
(End) Patricia Vannier [CDS] 09-Apr-2023