%0 Generic %1 lewis2020galactic %A Lewis, Joseph S. W. %A Ocvirk, Pierre %A Aubert, Dominique %A Sorce, Jenny G. %A Shapiro, Paul R. %A Deparis, Nicolas %A Dawoodbhoy, Taha %A Teyssier, Romain %A Yepes, Gustavo %A Gottlober, Stefan %A Ahn, Kyungjin %A Iliev, Ilian T. %A Chardin, Jonathan %D 2020 %K library %T Galactic ionising photon budget during the Epoch ofReionisation in the Cosmic Dawn II simulation %U http://arxiv.org/abs/2001.07785 %X Cosmic Dawn ("CoDa") II yields the first statistically-meaningful determination of the relative contribution to reionization by galaxies of different halo mass, from a fully-coupled radiation-hydrodynamics simulation of the epoch of reionization large enough ($100$ Mpc) to model global reionization while resolving the formation of all galactic halos above $\sim 10^8 \msol$. Cell transmission inside high-mass haloes is bi-modal -- ionized cells are transparent, while neutral cells absorb the photons their stars produce - and the halo escape fraction $ \fesc$ reflects the balance of star formation rate ("SFR") between these modes. The latter is increasingly prevalent at higher halo mass, driving down $\fesc$ (we provide analytical fits to our results), whereas halo escape luminosity, proportional to $\times SFR$, increases with mass. Haloes with dark matter masses within $6\cdot 10^8 < < 310^10 \msol$ produce $80$% of the escaping photons at z=7, when the Universe is 50% ionized, making them the main drivers of cosmic reionization. Less massive haloes, though more numerous, have low SFRs and contribute less than 10% of the photon budget then, despite their high $\fesc$. High mass haloes are too few and too opaque, contributing $<10$% despite their high SFRs. The dominant mass range is lower (higher) at higher (lower) redshift, as mass function and reionization advance together (e.g. at z$=8.5$, x$_HI=0.9$, $< 5.10^9 \msol$ haloes contributed $80$%). Galaxies with UV magnitudes $M_AB1600$ between $-12$ and $-19$ dominated reionization between z$=6$ and 8.

@misc{lewis2020galactic, abstract = {Cosmic Dawn ("CoDa") II yields the first statistically-meaningful determination of the relative contribution to reionization by galaxies of different halo mass, from a fully-coupled radiation-hydrodynamics simulation of the epoch of reionization large enough ($\sim 100$ Mpc) to model global reionization while resolving the formation of all galactic halos above $\sim 10^8 \msol$. Cell transmission inside high-mass haloes is bi-modal -- ionized cells are transparent, while neutral cells absorb the photons their stars produce - and the halo escape fraction $ \fesc$ reflects the balance of star formation rate ("SFR") between these modes. The latter is increasingly prevalent at higher halo mass, driving down $\fesc$ (we provide analytical fits to our results), whereas halo escape luminosity, proportional to $\fesc \times {\rm SFR}$, increases with mass. Haloes with dark matter masses within $6\cdot 10^{8} \msol < \mh < 3\cdot 10^{10} \msol$ produce $\sim 80$% of the escaping photons at z=7, when the Universe is 50% ionized, making them the main drivers of cosmic reionization. Less massive haloes, though more numerous, have low SFRs and contribute less than 10% of the photon budget then, despite their high $\fesc$. High mass haloes are too few and too opaque, contributing $<10$% despite their high SFRs. The dominant mass range is lower (higher) at higher (lower) redshift, as mass function and reionization advance together (e.g. at z$=8.5$, x$_{\rm HI}=0.9$, $\mh < 5.10^9 \msol$ haloes contributed $\sim 80$%). Galaxies with UV magnitudes $M_{AB1600}$ between $-12$ and $-19$ dominated reionization between z$=6$ and 8.}, added-at = {2020-01-23T05:25:11.000+0100}, author = {Lewis, Joseph S. W. and Ocvirk, Pierre and Aubert, Dominique and Sorce, Jenny G. and Shapiro, Paul R. and Deparis, Nicolas and Dawoodbhoy, Taha and Teyssier, Romain and Yepes, Gustavo and Gottlober, Stefan and Ahn, Kyungjin and Iliev, Ilian T. and Chardin, Jonathan}, biburl = {https://www.bibsonomy.org/bibtex/2f21b9af411b0d30ec669b477695e61db/gpkulkarni}, description = {Galactic ionising photon budget during the Epoch ofReionisation in the Cosmic Dawn II simulation}, interhash = {88881b7c828cd1cccff67409e8718f7a}, intrahash = {f21b9af411b0d30ec669b477695e61db}, keywords = {library}, note = {cite arxiv:2001.07785Comment: Submitted to MNRAS}, timestamp = {2020-01-23T05:25:11.000+0100}, title = {Galactic ionising photon budget during the Epoch ofReionisation in the Cosmic Dawn II simulation}, url = {http://arxiv.org/abs/2001.07785}, year = 2020 }