The Fate of the First Galaxies. II. Effects of Radiative Feedback

By M. Ricotti, Nickolay Y. Gnedin, J. Michael Shull. 2001

165 citations recorded by the source corpus.

We use three-dimensional cosmological simulations with radiative transfer to study the formation and evolution of the first galaxies in a ΛCDM cosmology. The simulations include continuum radiative transfer using the optically thin variable Eddington tensor (OTVET) approximation and line radiative transfer in the H2 Lyman-Werner bands of the UV background radiation. Chemical and thermal processes are treated in detail, particularly the ones relevant for H2 formation and destruction. We find that the first luminous objects ("small-halo objects") are characterized by bursting star formation (SF) that is self-regulated by a feedback process acting on cosmological instead of galactic scales. The global SF history is regulated by the mean number of ionizing photons that escape from each source, ϵUV⟨fesc⟩. It is almost independent of the assumed SF efficiency parameter, ϵ*, and the intensity of the dissociating background. The main feedback process that regulates the SF is the reformation of H2 in front of H II regions and inside relic H II regions. The H II regions remain confined inside filaments, maximizing the production of H2 in overdense regions through cyclic destruction/reformation of H2. If ϵUV⟨fesc⟩ > 10-7/ϵ*, the SF is self-regulated, photoevaporation of small-halo objects dominates the metal pollution of the low-density intergalactic medium, and the mass of produced metals depends only on ⟨fesc⟩. If ϵUV⟨fesc⟩ ≲ 10-7/ϵ*, positive feedback dominates, and small-halo objects constitute the bulk of the mass in stars and metals until at least redshift z ~ 10. Small-halo objects cannot reionize the universe because the feedback mechanism confines the H II regions inside the large-scale structure filaments. In contrast to massive objects ("large halos"), which can reionize voids, small-halo objects partially ionize only the dense filaments while leaving the voids mostly neutral.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/0299f704d95ed2e6d8ccb3c5f2dd4b9b85a11892

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Citations in the corpus

Simulations of Early Structure Formation: Primordial Gas Clouds (2003, methodology): “Ricotti et al. (2002b) presented extensive tests using a series of simulations and examined the effect of various parameters on the global star formation rate.”
The Fate of the First Galaxies. I. Self-consistent Cosmological Simulations with Radiative Transfer (2001, background): “Detailed atomic and molecular physics is included, although we have not included ‘‘ supernova feedback ’’ (M. Ricotti et al. 2002, in preparation).”
Effect of Primordial Black Holes on the Cosmic Microwave Background and Cosmological Parameter Estimates (2007, background): “It is not obvious that the star formation efficiency and other internal properties of the first galaxies would be affected because feedback effects such as photo-evaporation from internal sources and SN explosions are probably dominant (Ricotti et al. 2002a,b).”
Formation Histories of Dwarf Galaxies in the Local Group (2004, methodology): “By including 3D radiative transfer of ionizing radiation (Ricotti et al 2002a) in the simulations we are able to model two additional feedbacks: the positive feedback for H2 formation and the photoevaporation of dwarfs from internal sources.”
The first galaxies : assembly, cooling and the onset of turbulence (2008, background): “…formation in a multi-phase, interstellar medium (Thoul & Weinberg 1996; Mac Low & Ferrara 1999; Madau et al. 2001; Mori et al. 2002; Oh & Haiman 2002; Ricotti et al. 2002a,b; Scannapieco et al. 2002; Thacker et al. 2002; Wada & Venkatesan 2003; Dijkstra et al. 2004; Read et al. 2006; Ricotti et…”
Detecting the Earliest Galaxies through Two New Sources of 21 Centimeter Fluctuations (2004, background): “Although this gas may be dispersed due to internal feedback from star formation due to molecular hydrogen cooling (Oh & Haiman 2003; Ricotti et al. 2002), if stars cannot form then the dense gas minihalos produce 21cm fluctuations (Iliev et al. 2002, 2003).”
Self-regulated reionization (2006, background): “Some smaller-scale reionization simulations have been performed that couple gas and N-body dynamics to radiative transfer, which, in principle, takes account of the feedback effect ofJeans- c© 2006 RAS, MNRAS000, 1 mass filtering (Ricotti et al. 2002).”
X-ray pre-ionization powered by accretion on the first black holes – I. A model for the WMAP polarization measurement (2003, methodology): “Note that some cosmological simulations presented here include the effects of SN explosions, using the recipe discussed in Gnedin (1998), in contrast to earlier papers in this series (Ricotti et al. 2002a,b).”
The First Stars (2003, background): “Second, the free electrons in relic H II regions (Oh & Haiman 2003), or inside the outer boundary of a still-active one (Ricotti et al. 2001, 2002a,b), may accomplish the same.”
PRE-REIONIZATION FOSSILS, ULTRA-FAINT DWARFS, AND THE MISSING GALACTIC SATELLITE PROBLEM (2008, background): “Star formation in halos this small is possible only before reionization and is widespread if “positive” feedback plays a significant role in regulating star formation in the first galaxies (Ricotti et al. 2001, 2002a, 2002b).”
Suppression of H2 Cooling in the Ultraviolet Background (2007, background): “In all studies that include radiation sources in halos less than 104 K halos, the largest the soft UVB flux can get before the T > 104 K halos dominate the emission is J LW21 1 (see Haiman et al. 2000; Ricotti et al. 2002b, 2002a WA05).”
Signatures of X-rays in the early Universe (2012, background): “…(i.e. radiative feedback) was initially suspected of being important (e.g. Shapiro et al. 1994; Thoul & Weinberg 1996; Gnedin 2000), later studies concluded that its impact was smaller at high-redshifts (e.g. Ricotti et al. 2002; Kuhlen & Madau 2005; Mesinger & Dijkstra 2008; Okamoto et al. 2008).”
Early Cosmological H II/He III Regions and Their Impact on Second-Generation Star Formation (2006, background): “Starting from the central source, an ionization front (I-front) is advanced on the path over the segment length li between the ith and (iþ 1)th evaluation points.”