Bibcode
Pawlik, A. H.; Schaye, Joop; Dalla Vecchia, C.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 451, Issue 2, p.1586-1605
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8
2015
Citations
62
Refereed citations
57
Description
We present a suite of cosmological radiation-hydrodynamical simulations
of the assembly of galaxies driving the reionization of the
intergalactic medium (IGM) at z ≳ 6. The simulations account for
the hydrodynamical feedback from photoionization heating and the
explosion of massive stars as supernovae (SNe). Our reference
simulation, which was carried out in a box of size 25 h-1
comovingMpc using 2 × 5123 particles, produces a
reasonable reionization history and matches the observed UV luminosity
function of galaxies. Simulations with different box sizes and
resolutions are used to investigate numerical convergence, and
simulations in which either SNe or photoionization heating or both are
turned off, are used to investigate the role of feedback from star
formation. Ionizing radiation is treated using accurate radiative
transfer at the high spatially adaptive resolution at which the
hydrodynamics is carried out. SN feedback strongly reduces the star
formation rates (SFRs) over nearly the full mass range of simulated
galaxies and is required to yield SFRs in agreement with observations.
Photoheating helps to suppress star formation in low-mass galaxies, but
its impact on the cosmic SFR is small. Because the effect of
photoheating is masked by the strong SN feedback, it does not imprint a
signature on the UV galaxy luminosity function, although we note that
our resolution is insufficient to model star-forming minihaloes cooling
through molecular hydrogen transitions. Photoheating does provide a
strong positive feedback on reionization because it smooths density
fluctuations in the IGM, which lowers the IGM recombination rate
substantially. Our simulations demonstrate a tight non-linear coupling
of galaxy formation and reionization, motivating the need for the
accurate and simultaneous inclusion of photoheating and SN feedback in
models of the early Universe.
Related projects
Numerical Astrophysics: Galaxy Formation and Evolution
How galaxies formed and evolved through cosmic time is one of the key questions of modern astronomy and astrophysics. Cosmological time- and length-scales are so large that the evolution of individual galaxies cannot be directly observed. Only through numerical simulations can one follow the emergence of cosmic structures within the current
Claudio
Dalla Vecchia