The imprint of cosmological non-Gaussianities on primordial structure formation

Abstract

We study via numerical N-body/SPH chemistry simulations the effects of primordial non-Gaussianities on the formation of the first stars and galaxies, and investigate the impact of supernova feedback in cosmologies with different fnl. Density distributions are biased to higher values, so star formation and the consequent feedback processes take place earlier in high-fnl models and later in low-fnl ones. Mechanical feedback is responsible for shocking and evacuating the gas from star forming sites earlier in the highly non-Gaussian cases, because of the larger bias at high densities. Chemical feedback translates into high-redshift metal filling factors that are larger by some orders of magnitude for larger fnl, but that converge within one Gyr, for both population III and population II-I stellar regimes. The efficient enrichment process, though, leads to metallicities > 0.01 Zsun by redshift ~9, almost independently from fnl. The impact of non-Gaussianities on the formation of dark-matter haloes at high redshift is directly reflected in the properties of the gas in these haloes, as models with larger fnl show more concentrated gas profiles at early times. Non-Gaussian signatures in the gas behaviour are lost after the first feedback takes place and introduces a significant degree of turbulence and chaotic motions.

10 pages, 9 figures - accepted for publication in MNRAS

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• JWST high-z galaxy constraints on warm and cold dark matter models
• 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
• PopIII signatures in the spectra of PopII/I GRBs
• Testing primordial non-Gaussianities on galactic scales at high redshift
• Hydrodynamical chemistry simulations of the SZ effect and the impacts from primordial non-Gaussianities