%0 Generic %1 hutter2014visibility %A Hutter, A. %A Dayal, P. %A Partl, A. M. %A Müller, V. %D 2014 %K alpha emitters lyman simulation %T The visibility of Lyman Alpha Emitters: constraining reionization, ionizing photons and dust %U http://arxiv.org/abs/1401.2830 %X We couple state of the art cosmological simulations (GADGET-2) with a dust model and a radiative transfer code (pCRASH) to build a complete model for high-redshift Lyman Alpha emitters (LAEs). Due to poor constraints available on the escape fraction of HI ionizing photons (f_esc) from galaxies, we use five different values f_esc=0.05,0.25,0.5,0.75,0.95 to post-process the cosmological simulation with pCRASH. Starting from a completely neutral Universe, we run pCRASH until reionization is complete, i.e. the average neutral hydrogen (HI) fraction drops to <X_HI> ~ 10^-4. For a given f_esc and <X_HI> combination, the only free-parameter left to match model results to observations is the relative escape of Lyman Alpha (Lya) and continuum photons from the galactic environment (f_\alpha/f_c). Starting from a scenario wherein dust is homogeneously distributed (f_\alpha/f_c ~ 0.68), we find that the observed LAE UV and Lya luminosity functions (LFs) jointly constrain f_esc ~ 0.05 and <X_HI> <= 0.1. In the scenario that dust is clumped, we find a three-dimensional degeneracy between f_esc, <X_HI> and f_\alpha/f_c such that a decrease in the intrinsic Lya luminosity can be compensated by an increase in the Lya transmission through the intergalactic medium and/or an increasing Lya escape out of the galactic environment. In the latter scenario, the theoretical model can be reconciled with observations for a much larger parameter space: <X_HI> ~ 0.5-10^-4, f_esc ~ 0.05-0.50 and f_\alpha/f_c=0.6-1.8. In other words, if dust is indeed clumped in the interstellar medium of high-redshift galaxies, we can not differentiate between a Universe which is either completely ionized or half neutral, or has an f_esc ranging between 5-50%.

@misc{hutter2014visibility, abstract = {We couple state of the art cosmological simulations (GADGET-2) with a dust model and a radiative transfer code (pCRASH) to build a complete model for high-redshift Lyman Alpha emitters (LAEs). Due to poor constraints available on the escape fraction of HI ionizing photons (f_esc) from galaxies, we use five different values f_esc=0.05,0.25,0.5,0.75,0.95 to post-process the cosmological simulation with pCRASH. Starting from a completely neutral Universe, we run pCRASH until reionization is complete, i.e. the average neutral hydrogen (HI) fraction drops to <X_HI> ~ 10^-4. For a given f_esc and <X_HI> combination, the only free-parameter left to match model results to observations is the relative escape of Lyman Alpha (Lya) and continuum photons from the galactic environment (f_\alpha/f_c). Starting from a scenario wherein dust is homogeneously distributed (f_\alpha/f_c ~ 0.68), we find that the observed LAE UV and Lya luminosity functions (LFs) jointly constrain f_esc ~ 0.05 and <X_HI> <= 0.1. In the scenario that dust is clumped, we find a three-dimensional degeneracy between f_esc, <X_HI> and f_\alpha/f_c such that a decrease in the intrinsic Lya luminosity can be compensated by an increase in the Lya transmission through the intergalactic medium and/or an increasing Lya escape out of the galactic environment. In the latter scenario, the theoretical model can be reconciled with observations for a much larger parameter space: <X_HI> ~ 0.5-10^-4, f_esc ~ 0.05-0.50 and f_\alpha/f_c=0.6-1.8. In other words, if dust is indeed clumped in the interstellar medium of high-redshift galaxies, we can not differentiate between a Universe which is either completely ionized or half neutral, or has an f_esc ranging between 5-50%.}, added-at = {2014-01-14T10:25:18.000+0100}, author = {Hutter, A. and Dayal, P. and Partl, A. M. and Müller, V.}, biburl = {https://www.bibsonomy.org/bibtex/24114d931c075494a36faedd1dd913a86/miki}, description = {[1401.2830] The visibility of Lyman Alpha Emitters: constraining reionization, ionizing photons and dust}, interhash = {5ed576cdcc5f864c28aa8a24741a445a}, intrahash = {4114d931c075494a36faedd1dd913a86}, keywords = {alpha emitters lyman simulation}, note = {cite arxiv:1401.2830Comment: 19 pages, 11 figures, 1 table, comments welcome, submitted to MNRAS}, timestamp = {2014-01-14T10:25:18.000+0100}, title = {The visibility of Lyman Alpha Emitters: constraining reionization, ionizing photons and dust}, url = {http://arxiv.org/abs/1401.2830}, year = 2014 }