dc.contributor.author Garel, Thibault en dc.contributor.author Blaizot, Jérémy en dc.contributor.author Rosdahl, Joakim en dc.contributor.author Michel-Dansac, Léo en dc.contributor.author Haehnelt, Martin en dc.contributor.author Katz, Harley en dc.contributor.author Kimm, Taysun en dc.contributor.author Verhamme, Anne en dc.date.accessioned 2021-04-19T23:31:49Z dc.date.available 2021-04-19T23:31:49Z dc.identifier.issn 0035-8711 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/321315 dc.description.abstract The Ly$\alpha$ emission line is one of the most promising probes of cosmic reionisation but isolating the signature of a change in the ionisation state of the IGM is challenging because of intrinsic evolution and internal radiation transfer effects. We present the first study of the evolution of Ly$\alpha$ emitters (LAE) during the epoch of reionisation based on a full radiation-hydrodynamics cosmological simulation that is able to capture both the large-scale process of reionisation and the small-scale properties of galaxies. We predict the Ly$\alpha$ emission of galaxies in the $10^3$ cMpc$^3$ SPHINX simulation at $6\leq z\leq9$ by computing the full Ly$\alpha$ radiation transfer from ISM to IGM scales. SPHINX is able to reproduce many observational constraints such as the UV/Ly$\alpha$ luminosity functions and stellar mass functions at z $\geq$ 6 for the dynamical range probed by our simulation ($M_{\rm 1500}\gtrsim-18$, $L_{\rm Ly\alpha}\lesssim10^{42}$ erg/s, $M_{\star}\lesssim10^9$ M$_{\odot}$). As intrinsic Ly$\alpha$ emission and internal Ly$\alpha$ escape fractions barely evolve from $z=6$ to 9, the observed suppression of Ly$\alpha$ luminosities with increasing redshift is fully attributed to IGM absorption. For most observable galaxies ($M_{\rm 1500}\lesssim-16$), the Ly$\alpha$ line profiles are slightly shifted to the red due to internal radiative transfer effects which mitigates the effect of IGM absorption. Overall, the enhanced Ly$\alpha$ suppression during reionisation traces the IGM neutral fraction $x_{\rm HI}$ well but the predicted amplitude of this reduction is a strong function of the Ly$\alpha$ peak shift, which is set at ISM/CGM scales. We find that a large number of LAEs could be detectable in very deep surveys during reionisation when $x_{\rm HI}$ is still $\approx 50\%$. dc.publisher Royal Astronomical Society dc.rights All rights reserved dc.title Ly $α$ as a tracer of cosmic reionization in the SPHINX radiation-hydrodynamics cosmological simulation en dc.type Article prism.endingPage 1926 prism.issueIdentifier 2 en prism.publicationName Monthly Notices of the Royal Astronomical Society en prism.startingPage 1902 prism.volume 504 en dc.identifier.doi 10.17863/CAM.68439 dcterms.dateAccepted 2021-04-07 en rioxxterms.versionofrecord 10.1093/mnras/stab990 en rioxxterms.version VoR rioxxterms.licenseref.uri http://www.rioxx.net/licenses/all-rights-reserved en rioxxterms.licenseref.startdate 2021-04-07 en dc.contributor.orcid Haehnelt, Martin [0000-0001-8443-2393] dc.identifier.eissn 1365-2966 rioxxterms.type Journal Article/Review en pubs.funder-project-id STFC (ST/S000623/1) pubs.funder-project-id SCIENCE & TECHNOLOGY FACILITIES COUNCIL (ST/N000927/1) cam.issuedOnline 2021-04-14 en cam.orpheus.success Mon Jun 14 07:30:46 BST 2021 - The item has an open VoR version. * cam.orpheus.counter 7 * rioxxterms.freetoread.startdate 2100-01-01
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