Original language | English |
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Pages (from-to) | 1113-1122 |
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Journal | Monthly Notices of the Royal Astronomical Society |
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Volume | 421 |
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Issue number | 2 |
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DOIs | |
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Publication status | Published - 1 Apr 2012 |
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We study via numerical N-body/smoothed particle hydrodynamics 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 >rsim 10-2
Z⊙ 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. Despite this, our results support the idea that
non-Gaussianities can be imprinted in the gaseous and stellar features
of primordial structures in the high-redshift Universe.
- cosmology: theory, dark ages, reionization, first stars, early Universe
ID: 11173566