Open AccessCosmological reionization around the first stars: Monte Carlo radiative transfer
Author(s) -
Ciardi B.,
Ferrara A.,
Marri S.,
Raimondo G.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04316.x
Subject(s) - physics , reionization , astrophysics , radiative transfer , metallicity , galaxy , stars , universe , dark matter , astronomy , redshift , quantum mechanics
We study the evolution of ionization fronts around the first protogalaxies by using high‐resolution numerical cosmological (Λ+ cold dark matter, CDM, model) simulations and Monte Carlo radiative transfer methods. We present the numerical scheme in detail and show the results of test runs from which we conclude that the scheme is both fast and accurate. As an example of interesting cosmological application, we study the reionization produced by a stellar source of total mass M=2×10 8 M ⊙ turning on at z≈12, located at a node of the cosmic web. The study includes a spectral energy distribution of a zero‐metallicity stellar population, and two initial mass functions (IMFs; Salpeter/Larson). The expansion of the ionization front (I‐front) is followed as it breaks out from the galaxy and is channelled by the filaments into the voids, assuming (in a 2D representation) a characteristic butterfly shape. The ionization evolution is very well tracked by our scheme, as realized by the correct treatment of the channelling and shadowing effects resulting from overdensities. We confirm previous claims that both the shape of the IMF and the ionizing power metallicity dependence are important to correctly determine the reionization of the Universe.