Umberto Maio, Sadegh Khochfar
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.
View original:
http://arxiv.org/abs/1110.0493
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