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The First Stars and Galaxies: Challenges for the Next Decade Participants
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Poster
Title: Local and Global Radiative Feedback: the Rise of Early Stellar Populations Author(s): Robert Hueckstaedt Abstract: How the first stars regulated the formation of later generations by their intense UV flux is key to the assembly of primeval galaxies, the rise of the first stellar populations, and the onset of cosmological reionization. It is commonly held that photoevaporation of cosmological halos by nearby Pop III stars quenched new star formation, and that the rise of a global Lyman-Werner (LW) background prevented neutral halos from hosting new stars at lower redshifts. We present a survey of halo photoevaporation by high-mass and low-mass primordial stars over a range of LW backgrounds with simulations that self-consistently solve hydrodynamics, radiative transfer, and primordial gas chemistry. We find that ionizing and LW radiative feedback is much less destructive to star formation in halos than is generally believed, and that it can even accelerate the collapse of baryons into new stars in some cases. Partial photoevaporation of a halo may even allow it to form a star that was previously suppressed by a LW background. Our findings suggest that primordial star formation may have been common down to much lower redshifts than are currently supposed. We provide analytical fits to local radiative feedback that can be used in large scale cosmological simulations with box sizes that are too large to directly resolve halo photoevaporation.
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