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dc.contributor.authorBosman, Sarah EI
dc.contributor.authorFan, Xiaohui
dc.contributor.authorJiang, Linhua
dc.contributor.authorReed, Sophie L
dc.contributor.authorMatsuoka, Yoshiki
dc.contributor.authorBecker, George D
dc.contributor.authorHaehnelt, Martin G
dc.date.accessioned2018-09-20T12:02:37Z
dc.date.available2018-09-20T12:02:37Z
dc.date.issued2018
dc.identifier.issn1365-2966
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/280419
dc.description.abstractWe present measurements of the mean and scatter of the IGM Lyman-{\alpha} opacity at 4.9 < z < 6.1 along the lines of sight of 62 quasars at z > 5.7, the largest sample assembled at these redshifts to date by a factor of two. The sample size enables us to sample cosmic variance at these redshifts more robustly than ever before. The spectra used here were obtained by the SDSS, DES-VHS and SHELLQs collaborations, drawn from the ESI and X-Shooter archives, reused from previous studies or observed specifically for this work. We measure the effective optical depth of Lyman-{\alpha} in bins of 10, 30, 50 and 70 cMpc h-1, construct cumulative distribution functions under two treatments of upper limits on flux and explore an empirical analytic fit to residual Lyman-{\alpha} transmission. We verify the consistency of our results with those of previous studies via bootstrap re-sampling and confirm the existence of tails towards high values in the opacity distributions, which may persist down to z = 5.2. Comparing our results with predictions from cosmological simulations, we find further strong evidence against models that include a spatially uniform ionizing background and temperature-density relation. We also compare to IGM models that include either a fluctuating UVB dominated by rare quasars or temperature fluctuations due to patchy reionization. Although both models produce better agreement with the observations, neither fully captures the observed scatter in IGM opacity. Our sample of 62 z > 5.7 quasar spectra opens many avenues for future study of the reionisation epoch.
dc.publisherOxford University Press
dc.titleNew constraints on Lyman-α opacity with a sample of 62 quasars at z > 5.7
dc.typeArticle
prism.endingPage1076
prism.publicationNameMonthly Notices of the Royal Astronomical Society
prism.startingPage1055
prism.volume479
dc.identifier.doi10.17863/CAM.27790
dcterms.dateAccepted2018-05-16
rioxxterms.versionofrecord10.1093/mnras/sty1344
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.licenseref.startdate2018-05-16
dc.contributor.orcidHaehnelt, Martin [0000-0001-8443-2393]
dc.identifier.eissn1365-2966
rioxxterms.typeJournal Article/Review
pubs.funder-project-idScience and Technology Facilities Council (ST/N000927/1)
cam.issuedOnline2018-05-21
cam.orpheus.successThu Jan 30 10:54:33 GMT 2020 - The item has an open VoR version.
rioxxterms.freetoread.startdate2100-01-01


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