%0 Generic %1 kostyuk2022ionizing %A Kostyuk, Ivan %A Nelson, Dylan %A Ciardi, Benedetta %A Glatzle, Martin %A Pillepich, Annalisa %D 2022 %K library %T Ionizing photon production and escape fractions during cosmic reionization in the TNG50 simulation %U http://arxiv.org/abs/2207.11278 %X In this work we investigate the dependence of the escape fraction of ionizing photons, $f_esc$, on various galaxy and host halo properties during the epoch of reionization. We post-process the TNG50 magneto-hydrodynamical simulation from the IllustrisTNG project using the 3D multi-frequency radiative transfer code CRASH. Our work covers the stellar mass range $10^6 łesssim M_\star/M_ødot 10^8$ at redshifts $6 < z < 10$. Adopting an unresolved, cloud-scale escape fraction parameter of unity, the halo escape fraction $f_esc$ increases with mass from $0.3$ at $M_= 10^6$M$_ødot$ to $0.6$ at $M_= 10^7.5$M$_ødot$, after which we find hints of a turnover and decreasing escape fractions for even more massive galaxies. However, we demonstrate a strong and non-linear dependence of $f_\rm esc$ on the adopted sub-grid escape fraction. In addition, $f_esc$ has significant scatter at fixed mass, driven by diversity in the ionizing photon rate together with a complex relationship between (stellar) source positions and the underling density distribution. The global emissivity is consistent with observations for reasonable cloud-scale absorption values, and halos with a stellar mass $10^7.5$M$_ødot$ contribute the majority of ionizing photons at all redshifts. Incorporating dust reduces $f_esc$ by a few percent at $M_10^6.5$M$_ødot$, and up to 10\% for larger halos. Our multi-frequency approach shows that $f_esc$ depends on photon energy, and is reduced substantially at $E>54.4$eV versus lower energies. This suggests that the impact of high energy photons from binary stars is reduced when accounting for an energy dependent escape fraction.

@misc{kostyuk2022ionizing, abstract = {In this work we investigate the dependence of the escape fraction of ionizing photons, $f_{\rm esc}$, on various galaxy and host halo properties during the epoch of reionization. We post-process the TNG50 magneto-hydrodynamical simulation from the IllustrisTNG project using the 3D multi-frequency radiative transfer code CRASH. Our work covers the stellar mass range $10^6 \lesssim M_\star/{\rm M_\odot} \lesssim 10^8$ at redshifts $6 < z < 10$. Adopting an unresolved, cloud-scale escape fraction parameter of unity, the halo escape fraction $f_{\rm esc}$ increases with mass from $\sim 0.3$ at $M_\star = 10^6$M$_\odot$ to $\sim 0.6$ at $M_\star = 10^{7.5}$M$_\odot$, after which we find hints of a turnover and decreasing escape fractions for even more massive galaxies. However, we demonstrate a strong and non-linear dependence of $f_{\rm esc}$ on the adopted sub-grid escape fraction. In addition, $f_{\rm esc}$ has significant scatter at fixed mass, driven by diversity in the ionizing photon rate together with a complex relationship between (stellar) source positions and the underling density distribution. The global emissivity is consistent with observations for reasonable cloud-scale absorption values, and halos with a stellar mass $\lesssim 10^{7.5}$M$_\odot$ contribute the majority of ionizing photons at all redshifts. Incorporating dust reduces $f_{\rm esc}$ by a few percent at $M_\star \lesssim 10^{6.5}$M$_\odot$, and up to 10\% for larger halos. Our multi-frequency approach shows that $f_{\rm esc}$ depends on photon energy, and is reduced substantially at $E>54.4$eV versus lower energies. This suggests that the impact of high energy photons from binary stars is reduced when accounting for an energy dependent escape fraction.}, added-at = {2022-07-26T10:45:40.000+0200}, author = {Kostyuk, Ivan and Nelson, Dylan and Ciardi, Benedetta and Glatzle, Martin and Pillepich, Annalisa}, biburl = {https://www.bibsonomy.org/bibtex/28cc0a7bdd4603f95f2b9573942b1f098/gpkulkarni}, description = {Ionizing photon production and escape fractions during cosmic reionization in the TNG50 simulation}, interhash = {69416ee4ab87cf39821917de3219d137}, intrahash = {8cc0a7bdd4603f95f2b9573942b1f098}, keywords = {library}, note = {cite arxiv:2207.11278Comment: 19 pages, 15 figures, submitted to MNRAS}, timestamp = {2022-07-26T10:45:40.000+0200}, title = {Ionizing photon production and escape fractions during cosmic reionization in the TNG50 simulation}, url = {http://arxiv.org/abs/2207.11278}, year = 2022 }