Mass bias and cosmological constraints from Planck cluster clustering

¹ Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna, Via Piero Gobetti 93/2, 40129 Bologna, Italy
e-mail: giorgio.lesci2@unibo.it
² INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
³ INAF – Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milan, Via E. Bianchi 46, 20121 Merate, Italy
⁴ INFN – Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy

Received: 27 February 2023
Accepted: 20 April 2023

Abstract

Aims. We analysed the 3D clustering of the Planck sample of Sunyaev–Zeldovich (SZ) selected galaxy clusters, focusing on the redshift-space two-point correlation function (2PCF). We compared our measurements to theoretical predictions of the standard Λ cold dark matter (ΛCDM) cosmological model, deriving an estimate of the Planck mass bias, b_SZ, and cosmological parameters.

Methods. We measured the 2PCF of the sample in the cluster-centric radial range r ∈ [10, 150] h⁻¹ Mpc, considering 920 galaxy clusters with redshift z ≤ 0.8. A Markov chain Monte Carlo analysis was performed to constrain b_SZ, assuming priors on cosmological parameters from Planck cosmic microwave background (CMB) results. We also adopted priors on b_SZ from external data sets to constrain the cosmological parameters Ω_m and σ₈.

Results. We obtained (1−b_SZ) = 0.62_−0.11^+0.14, which agrees with the value required to reconcile primary CMB and cluster count observations. By adopting priors on (1 − b_SZ) from external data sets, we derived results on Ω_m that fully agree and are competitive, in terms of uncertainties, with those derived from cluster counts. This confirms the importance of including clustering in cosmological studies in order to fully exploit the information from galaxy cluster statistics. On the other hand, we found that σ₈ is not constrained.