%0 Generic %1 kimm2016feedbackregulated %A Kimm, Taysun %A Katz, Harley %A Haehnelt, Martin %A Rosdahl, Joakim %A Devriendt, Julien %A Slyz, Adrianne %D 2016 %K escape fraction minihalo %T Feedback-regulated escape of LyC photons from mini-haloes during reionisation %U http://arxiv.org/abs/1608.04762 %X Reionisation in the early Universe is likely driven by dwarf galaxies. Using cosmological, zoom-in, radiation-hydrodynamic simulations, we study the escape of Lyman continuum (LyC) photons from mini-haloes with $M_halo łe 10^8\,M_ødot$. Our simulations include a new thermo-turbulent star formation model, non-equilibrium chemistry, and relevant stellar feedback processes (photoionisation by young massive stars, radiation pressure, and mechanical supernova explosions). We find that the photon number-weighted mean escape fraction in mini-haloes is higher ($\sim20$-$40\%$) than that in atomic-cooling haloes, although the instantaneous fraction in individual haloes varies significantly. The escape fraction from Pop III stars is found to be significant ($\ge10\%$) only when the mass is greater than $\sim$100\,\msun. Because star formation is stochastic and dominated by a few gas clumps, the escape fraction is generally determined by radiation feedback (heating due to photo-ionisation), rather than supernova explosions. We find that the resulting stellar mass of the proto-galaxies in mini-haloes follows the slope and normalisation reported in Kimm & Cen, which is similar to the empirical stellar mass-to-halo mass relation derived in the local Universe. Based on simple analytic calculations, we show that LyC photons from mini-haloes are, despite their high escape fractions, of minor importance for reionisation, as feedback reduces star formation very efficiently in mini-haloes. We confirm previous claims that stars in atomic-cooling haloes with masses $10^8\,M_ødotM_halo 10^11\,M_ødot$ are likely to be the most important source of reionisation.

@misc{kimm2016feedbackregulated, abstract = {Reionisation in the early Universe is likely driven by dwarf galaxies. Using cosmological, zoom-in, radiation-hydrodynamic simulations, we study the escape of Lyman continuum (LyC) photons from mini-haloes with $M_{\rm halo} \le 10^8\,M_\odot$. Our simulations include a new thermo-turbulent star formation model, non-equilibrium chemistry, and relevant stellar feedback processes (photoionisation by young massive stars, radiation pressure, and mechanical supernova explosions). We find that the photon number-weighted mean escape fraction in mini-haloes is higher ($\sim20$-$40\%$) than that in atomic-cooling haloes, although the instantaneous fraction in individual haloes varies significantly. The escape fraction from Pop III stars is found to be significant ($\ge10\%$) only when the mass is greater than $\sim$100\,\msun. Because star formation is stochastic and dominated by a few gas clumps, the escape fraction is generally determined by radiation feedback (heating due to photo-ionisation), rather than supernova explosions. We find that the resulting stellar mass of the proto-galaxies in mini-haloes follows the slope and normalisation reported in Kimm \& Cen, which is similar to the empirical stellar mass-to-halo mass relation derived in the local Universe. Based on simple analytic calculations, we show that LyC photons from mini-haloes are, despite their high escape fractions, of minor importance for reionisation, as feedback reduces star formation very efficiently in mini-haloes. We confirm previous claims that stars in atomic-cooling haloes with masses $10^8\,M_\odot\le M_{\rm halo} \le 10^{11}\,M_\odot$ are likely to be the most important source of reionisation.}, added-at = {2016-08-18T10:44:33.000+0200}, author = {Kimm, Taysun and Katz, Harley and Haehnelt, Martin and Rosdahl, Joakim and Devriendt, Julien and Slyz, Adrianne}, biburl = {https://www.bibsonomy.org/bibtex/21e81463b0bf37955eb18b74b7e02cb13/miki}, description = {[1608.04762] Feedback-regulated escape of LyC photons from mini-haloes during reionisation}, interhash = {3667a3bbd7b47d8f375a4a45f8d3457f}, intrahash = {1e81463b0bf37955eb18b74b7e02cb13}, keywords = {escape fraction minihalo}, note = {cite arxiv:1608.04762Comment: 21 pages, 15 figures, submitted to MNRAS}, timestamp = {2016-08-18T10:44:33.000+0200}, title = {Feedback-regulated escape of LyC photons from mini-haloes during reionisation}, url = {http://arxiv.org/abs/1608.04762}, year = 2016 }