%0 Generic %1 hutter2022astraeus %A Hutter, Anne %A Trebitsch, Maxime %A Dayal, Pratika %A Gottlöber, Stefan %A Yepes, Gustavo %A Legrand, Laurent %D 2022 %K library %T Astraeus VIII: A new framework for Lyman-$\alpha$ emitters applied to different reionisation scenarios %U http://arxiv.org/abs/2209.14592 %X We use the astraeus framework to investigate how the visibility and spatial distribution of Lyman-$\alpha$ (Ly$\alpha$) emitters (LAEs) during reionisation is sensitive to a halo mass-dependent fraction of ionising radiation escaping from the galactic environment ($f_esc$) and the ionisation topology. To this end, we consider the two physically plausible bracketing scenarios of $f_esc$ increasing and decreasing with rising halo mass. We derive the corresponding observed Ly$\alpha$ luminosities of galaxies for three different analytic Ly$\alpha$ line profiles and associated Ly$\alpha$ escape fraction ($f_esc^Ly\alpha$) models: importantly, we introduce two novel analytic Ly$\alpha$ line profile models that describe the surrounding interstellar medium (ISM) as outflowing dusty gas clumps. They are based on parameterising results from radiative transfer simulations, with one of them relating $f_esc^Ly\alpha$ to $f_esc$ by assuming the ISM of being interspersed with low-density tunnels. Our key findings are: (i) for outflowing clumps, the Ly$\alpha$ line profile develops from a central to double peak profile as a galaxy's halo mass increases; (ii) LAEs are galaxies with $M_h\gtrsim10^10M_ødot$ located in overdense and highly ionised regions; (iii) for this reason, the spatial distribution of LAEs is primarily sensitive to the global ionisation fraction and only weakly in second-order to the ionisation topology or a halo mass-dependent $f_esc$; (iv) furthermore, as the observed Ly$\alpha$ luminosity functions reflect the Ly$\alpha$ emission from more massive galaxies, there is a degeneracy between the $f_esc$-dependent intrinsic Ly$\alpha$ luminosity and the Ly$\alpha$ attenuation by dust in the ISM if $f_esc$ does not exceed $\sim50\%$.

@misc{hutter2022astraeus, abstract = {We use the {\sc astraeus} framework to investigate how the visibility and spatial distribution of Lyman-$\alpha$ (Ly$\alpha$) emitters (LAEs) during reionisation is sensitive to a halo mass-dependent fraction of ionising radiation escaping from the galactic environment ($f_\mathrm{esc}$) and the ionisation topology. To this end, we consider the two physically plausible bracketing scenarios of $f_\mathrm{esc}$ increasing and decreasing with rising halo mass. We derive the corresponding observed Ly$\alpha$ luminosities of galaxies for three different analytic Ly$\alpha$ line profiles and associated Ly$\alpha$ escape fraction ($f_\mathrm{esc}^\mathrm{Ly\alpha}$) models: importantly, we introduce two novel analytic Ly$\alpha$ line profile models that describe the surrounding interstellar medium (ISM) as outflowing dusty gas clumps. They are based on parameterising results from radiative transfer simulations, with one of them relating $f_\mathrm{esc}^\mathrm{Ly\alpha}$ to $f_\mathrm{esc}$ by assuming the ISM of being interspersed with low-density tunnels. Our key findings are: (i) for outflowing clumps, the Ly$\alpha$ line profile develops from a central to double peak profile as a galaxy's halo mass increases; (ii) LAEs are galaxies with $M_h\gtrsim10^{10}M_\odot$ located in overdense and highly ionised regions; (iii) for this reason, the spatial distribution of LAEs is primarily sensitive to the global ionisation fraction and only weakly in second-order to the ionisation topology or a halo mass-dependent $f_\mathrm{esc}$; (iv) furthermore, as the observed Ly$\alpha$ luminosity functions reflect the Ly$\alpha$ emission from more massive galaxies, there is a degeneracy between the $f_\mathrm{esc}$-dependent intrinsic Ly$\alpha$ luminosity and the Ly$\alpha$ attenuation by dust in the ISM if $f_\mathrm{esc}$ does not exceed $\sim50\%$.}, added-at = {2022-09-30T10:19:29.000+0200}, author = {Hutter, Anne and Trebitsch, Maxime and Dayal, Pratika and Gottlöber, Stefan and Yepes, Gustavo and Legrand, Laurent}, biburl = {https://www.bibsonomy.org/bibtex/2c1726f2f31a5f6cadba638367efc743e/gpkulkarni}, description = {Astraeus VIII: A new framework for Lyman-$\alpha$ emitters applied to different reionisation scenarios}, interhash = {e5f8a3623c65a570a6fe2c6b21e4410a}, intrahash = {c1726f2f31a5f6cadba638367efc743e}, keywords = {library}, note = {cite arxiv:2209.14592Comment: 25 pages, 9 figures, submitted to MNRAS; comments welcome}, timestamp = {2022-09-30T10:19:29.000+0200}, title = {Astraeus VIII: A new framework for Lyman-$\alpha$ emitters applied to different reionisation scenarios}, url = {http://arxiv.org/abs/2209.14592}, year = 2022 }