%0 Generic %1 lewis2022short %A Lewis, Joseph S. W. %A Ocvirk, Pierre %A Sorce, Jenny G. %A Dubois, Yohan %A Aubert, Dominique %A Conaboy, Luke %A Shapiro, Paul R. %A Dawoodbhoy, Taha %A Teyssier, Romain %A Yepes, Gustavo %A Gottlöber, Stefan %A Rasera, Yann %A Ahn, Kyungjin %A Iliev, Ilian T. %A Park, Hyunbae %A Thélie, Émilie %D 2022 %K library %T The short ionizing photon mean free path at z=6 in Cosmic Dawn III, a new fully-coupled radiation-hydrodynamical simulation of the Epoch of Reionization %U http://arxiv.org/abs/2202.05869 %X Recent determinations of the mean free path of ionising photons (mfp) in the intergalactic medium (IGM) at $z=6$ are lower than many theoretical predictions. In order to gain insight into this issue, we investigate the evolution of the mfp in our new massive fully coupled radiation hydrodynamics cosmological simulation of reionization: Cosmic Dawn III (CoDaIII). CoDaIII's scale ($94^3 \, cMpc^3$) and resolution ($8192^3$ grid) make it particularly suitable to study the evolution of the IGM during the Epoch of Reionization (EoR). The simulation was performed with RAMSES-CUDATON on Summit, and used 131072 processors coupled to 24576 GPUs, making it the largest EoR simulation, and largest RAMSES simulation ever performed. A superior agreement with global constraints on reionization is obtained in CoDaIII over CoDaII especially for the evolution of the neutral hydrogen fraction and the cosmic photo-ionization rate, thanks to an improved calibration, later end of reionization ($z=5.6$), and higher spatial resolution. Analyzing the mfp, we find that CoDaIII reproduces the most recent observations very well, from $z=6$ to $z=4.6$. We show that the distribution of the mfp in CoDaIII is bimodal, with short (neutral) and long (ionized) mfp modes, respectively, due to the patchiness of reionization and the co-existence of neutral versus ionized regions during the EoR. The neutral mode peaks at sub-kpc to kpc scales of mfp, while the ionized mode peak evolves from $0.1 Mpc/h$ at $z=7$ to $10$ Mpc/h at $z=5.2$. Computing the mfp as the average of the ionized mode provides the best match to the recent observational determinations. The distribution reduces to a single neutral (ionized) mode at $z>13$ ($z<5$).

@misc{lewis2022short, abstract = {Recent determinations of the mean free path of ionising photons (mfp) in the intergalactic medium (IGM) at $\rm z=6$ are lower than many theoretical predictions. In order to gain insight into this issue, we investigate the evolution of the mfp in our new massive fully coupled radiation hydrodynamics cosmological simulation of reionization: Cosmic Dawn III (CoDaIII). CoDaIII's scale ($\rm 94^3 \, cMpc^3$) and resolution ($\rm 8192^3$ grid) make it particularly suitable to study the evolution of the IGM during the Epoch of Reionization (EoR). The simulation was performed with RAMSES-CUDATON on Summit, and used 131072 processors coupled to 24576 GPUs, making it the largest EoR simulation, and largest RAMSES simulation ever performed. A superior agreement with global constraints on reionization is obtained in CoDaIII over CoDaII especially for the evolution of the neutral hydrogen fraction and the cosmic photo-ionization rate, thanks to an improved calibration, later end of reionization ($\rm z=5.6$), and higher spatial resolution. Analyzing the mfp, we find that CoDaIII reproduces the most recent observations very well, from $\rm z=6$ to $\rm z=4.6$. We show that the distribution of the mfp in CoDaIII is bimodal, with short (neutral) and long (ionized) mfp modes, respectively, due to the patchiness of reionization and the co-existence of neutral versus ionized regions during the EoR. The neutral mode peaks at sub-kpc to kpc scales of mfp, while the ionized mode peak evolves from $\rm 0.1 Mpc/h$ at $\rm z=7$ to $\sim 10$ Mpc/h at $\rm z=5.2$. Computing the mfp as the average of the ionized mode provides the best match to the recent observational determinations. The distribution reduces to a single neutral (ionized) mode at $\rm z>13$ ($\rm z<5$).}, added-at = {2022-02-15T04:57:14.000+0100}, author = {Lewis, Joseph S. W. and Ocvirk, Pierre and Sorce, Jenny G. and Dubois, Yohan and Aubert, Dominique and Conaboy, Luke and Shapiro, Paul R. and Dawoodbhoy, Taha and Teyssier, Romain and Yepes, Gustavo and Gottlöber, Stefan and Rasera, Yann and Ahn, Kyungjin and Iliev, Ilian T. and Park, Hyunbae and Thélie, Émilie}, biburl = {https://www.bibsonomy.org/bibtex/255d3a16241c4689e9568760fbe4a8a99/gpkulkarni}, description = {The short ionizing photon mean free path at z=6 in Cosmic Dawn III, a new fully-coupled radiation-hydrodynamical simulation of the Epoch of Reionization}, interhash = {af218813135f86548b33431d43f5cf91}, intrahash = {55d3a16241c4689e9568760fbe4a8a99}, keywords = {library}, note = {cite arxiv:2202.05869Comment: Submitted to MNRAS}, timestamp = {2022-02-15T04:57:14.000+0100}, title = {The short ionizing photon mean free path at z=6 in Cosmic Dawn III, a new fully-coupled radiation-hydrodynamical simulation of the Epoch of Reionization}, url = {http://arxiv.org/abs/2202.05869}, year = 2022 }