Orateur
Description
Galaxy clusters are a powerful cosmological probe: they track the most recent evolution of large scale structure and therefore are fundamental for testing the cosmological model in the recent Universe. To compare the observations of galaxy clusters with theoretical predictions and thus constrain the cosmological parameters of the underlying model, precise knowledge of cluster masses and redshifts is required. Scaling relations between the cluster masses and observables (like the richness in optical wavelength, $Y_{\text{SZ}}$ in the mm-band or $Y_X$ in X-rays) are usually used to compute the mass of clusters.
We provide a new scaling relation using a sample of clusters from the Planck Early Sunyaev-Zeldovich (ESZ) catalogue observed in X-rays by Chandra, and compare it to the results of the Planck collaboration from XMM-Newton observations of a subsample of the ESZ. We calibrate a mass bias for a subset of the Planck cosmological cluster sample using published weak-lensing data from the Canadian Cluster Cosmology Project and Multi Epoch Nearby Cluster Survey, for the new scaling relation as well as that from the Planck collaboration, using a novel method to account for selection effects. With these mass biases, we obtain $Y_{SZ} - M_{500}$ scaling relations that we apply to the full Planck cosmological cluster sample, to obtain new constraints on the cosmological parameters. We also provide constraints with a redshift evolution of the scaling relation fitted from the data instead of fixing it to the self-similar value, and find significant deviation from the self-similar value. We compare our results to those from recent analyses based on various cosmological probes, and find that our $S_8$ constraints are competitive with the tightest constraints from the literature. When assuming a self-similar redshift evolution, our constraints are in agreement with most late time probes and in tension with constraints from the CMB primary anisotropies. When fitting the redshift evolution from the data, we find no significant tension with results from either late time probes or the CMB.
| Astrophysics Field | Cosmology |
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