The clustering of galaxy clusters in cosmological models with non-Gaussian initial conditions: Predictions for future surveys

TL;DR

This paper predicts how non-Gaussian initial conditions in cosmological models affect galaxy cluster clustering, with implications for future X-ray and Sunyaev-Zel'dovich surveys, especially highlighting differences based on bispectrum shapes.

Contribution

It provides the first detailed predictions of galaxy cluster bias and clustering in non-Gaussian cosmologies for upcoming surveys, considering both local and equilateral bispectrum shapes.

Findings

Local shape non-Gaussianity significantly affects large-scale clustering.

Equilateral shape non-Gaussianity has a mild, hard-to-detect impact.

eROSITA survey is more sensitive to primordial non-Gaussianity.

Abstract

We predict the biasing and clustering properties of galaxy clusters that are expected to be observed in the catalogues produced by two forthcoming X-ray and Sunyaev-Zel'dovich effect surveys. We study a set of flat cosmological models where the primordial density probability distribution shows deviations from Gaussianity in agreement with current observational bounds form the background radiation. We consider both local and equilateral shapes for the primordial bispectrum in non-Gaussian models. The two catalogues investigated are those produced by the \emph{e}ROSITA wide survey and from a survey based on South Pole Telescope observations. It turns out that both the bias and observed power spectrum of galaxy clusters are severely affected in non-Gaussian models with local shape of the primordial bispectrum, especially at large scales. On the other hand, models with equilateral shape of the primordial bispectrum show only a mild effect at all scales, that is difficult to be detected with clustering observations. Between the two catalogues, the one performing better is the \emph{e}ROSITA one, since it contains only the largest masses, that are more sensitive to primordial non-Gaussianity.