Gas distribution, metal enrichment, and baryon fraction in Gaussian and non-Gaussian universes

Abstract

We study the cosmological evolution of baryons in universes with and without primordial non-Gaussianities via (large scale) N-body/hydrodynamical simulations, including gas cooling, star formation, stellar evolution, chemical enrichment from both population III and population II regimes, and feedback effects. We find that large fnl values for non-Gaussianities can alter the gas probability distribution functions, the metal pollution history, the halo baryon, gas and stellar fractions, mostly at early times. More precisely: (i) non-Gaussianities lead to an earlier evolution of primordial gas, structures, and star formation; (ii) metal enrichment starts earlier (with respect to the Gaussian scenario) in non-Gaussian models with larger fnl; (iii) gas fractions within the haloes are not significantly affected by the different values of fnl, with deviations of ~1-10%; (iv) the stellar fraction is quite sensitive to non-Gaussianities at early times, with discrepancies reaching up to a factor of ~10 at very high z, and rapidly converging at low z; (v) the trends at low redshift are independent from fnl: they are mostly led by the ongoing baryonic evolution and by the feedback mechanisms, which determine a ~25%-30% discrepancy in the baryon fraction of galaxy groups/clusters with respect to the cosmic values; (vi) non-Gaussianity impacts on the cluster X-ray emission or on the SZ effect(s) are expected to be not very large and dominated by feedback mechanisms, whereas some effects on the 21-cm emission can be expected at early times; (vii) in order to address non-Gaussianities in the cosmological structure contest, high-redshift (z~10) investigations are required: first stars, galaxies, quasars, and GRBs may be potential cosmological probes of non-Gaussianities.

17 pages, 8 figures - published on Classical and Quantum Gravity

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Cited by in corpus (20)

• Constraining the PopIII IMF with high-z GRBs
• Galaxy bias and primordial non-Gaussianity: insights from galaxy formation simulations with IllustrisTNG
• Simulating high-z Gamma-ray Burst host galaxies
• The First Billion Years of a Warm Dark Matter Universe
• Origin of Cosmic Chemical Abundances
• JWST high-z galaxy constraints on warm and cold dark matter models
• Robust PCA and MIC statistics of baryons in early mini-haloes
• Counts of high-redshift GRBs as probe of primordial non-Gaussianities
• Statistical properties of mass, star formation, chemical content and rotational patterns in early z > 9 structures
• Radiative feedback and cosmic molecular gas: the role of different radiative sources
• Atomic and molecular gas from the epoch of reionization down to redshift 2
• Radiative feedback and cosmic molecular gas: numerical method
• The seeds of supermassive black holes and the role of local radiation and metal spreading
• Simulating extremely metal-poor gas and DLA metal content at redshift z=7
• The imprint of cosmological non-Gaussianities on primordial structure formation
• Signatures of very massive stars: supercollapsars and their cosmological rate
• Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion
• Testing primordial non-Gaussianities on galactic scales at high redshift
• Hydrodynamical chemistry simulations of the SZ effect and the impacts from primordial non-Gaussianities
• The Lyman-alpha Forest as a tool for disentangling non-Gaussianities