The epoch of reionization in the R h = ct universe

Persistent Link:
http://hdl.handle.net/10150/615094
Title:
The epoch of reionization in the R h = ct universe
Author:
Melia, Fulvio; Fatuzzo, Marco
Affiliation:
The University of Arizona
Issue Date:
2016-01-11
Publisher:
OXFORD UNIV PRESS
Citation:
The epoch of reionization in the R h =  ct universe 2016, 456 (4):3422 Monthly Notices of the Royal Astronomical Society
Journal:
Monthly Notices of the Royal Astronomical Society
Rights:
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Collection Information:
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.
Abstract:
The measured properties of the epoch of reionization (EoR) show that reionization probably began around $z\sim 12-15$ and ended by $z=6$. In addition, a careful analysis of the fluctuations in the cosmic microwave background indicate a scattering optical depth $\tau\sim 0.066\pm0.012$ through the EoR. In the context of $\Lambda$CDM, galaxies at intermediate redshifts and dwarf galaxies at higher redshifts now appear to be the principal sources of UV ionizing radiation, but only for an inferred (ionizing) escape fraction $f_{ion}\sim 0.2$, which is in tension with other observations that suggest a value as small as $\sim 0.05$. In this paper, we examine how reionization might have progressed in the alternative Friedmann-Robertson Walker cosmology known as the $R_{\rm h}=ct$ Universe, and determine the value of $f_{ion}$ required with this different rate of expansion. We find that $R_{\rm h}=ct$ accounts quite well for the currently known properties of the EoR, as long as its fractional baryon density falls within the reasonable range $0.026\lesssim \Omega_b\lesssim 0.037$. This model can also fit the EoR data with $f_{ion}\sim 0.05$, but only if the Lyman continuum photon production is highly efficient and $\Omega_b \sim 0.037$. These results are still preliminary, however, given their reliance on a particular form of the star-formation rate density, which is still uncertain at very high redshifts. It will also be helpful to reconsider the EoR in $R_{\rm h}=ct$ when complete structure formation models become available.
ISSN:
0035-8711; 1365-2966
DOI:
10.1093/mnras/stv2902
Version:
Final accepted manuscript
Additional Links:
http://mnras.oxfordjournals.org/lookup/doi/10.1093/mnras/stv2902

Full metadata record

DC FieldValue Language
dc.contributor.authorMelia, Fulvioen
dc.contributor.authorFatuzzo, Marcoen
dc.date.accessioned2016-06-29T19:38:39Z-
dc.date.available2016-06-29T19:38:39Z-
dc.date.issued2016-01-11-
dc.identifier.citationThe epoch of reionization in the R h =  ct universe 2016, 456 (4):3422 Monthly Notices of the Royal Astronomical Societyen
dc.identifier.issn0035-8711-
dc.identifier.issn1365-2966-
dc.identifier.doi10.1093/mnras/stv2902-
dc.identifier.urihttp://hdl.handle.net/10150/615094-
dc.description.abstractThe measured properties of the epoch of reionization (EoR) show that reionization probably began around $z\sim 12-15$ and ended by $z=6$. In addition, a careful analysis of the fluctuations in the cosmic microwave background indicate a scattering optical depth $\tau\sim 0.066\pm0.012$ through the EoR. In the context of $\Lambda$CDM, galaxies at intermediate redshifts and dwarf galaxies at higher redshifts now appear to be the principal sources of UV ionizing radiation, but only for an inferred (ionizing) escape fraction $f_{ion}\sim 0.2$, which is in tension with other observations that suggest a value as small as $\sim 0.05$. In this paper, we examine how reionization might have progressed in the alternative Friedmann-Robertson Walker cosmology known as the $R_{\rm h}=ct$ Universe, and determine the value of $f_{ion}$ required with this different rate of expansion. We find that $R_{\rm h}=ct$ accounts quite well for the currently known properties of the EoR, as long as its fractional baryon density falls within the reasonable range $0.026\lesssim \Omega_b\lesssim 0.037$. This model can also fit the EoR data with $f_{ion}\sim 0.05$, but only if the Lyman continuum photon production is highly efficient and $\Omega_b \sim 0.037$. These results are still preliminary, however, given their reliance on a particular form of the star-formation rate density, which is still uncertain at very high redshifts. It will also be helpful to reconsider the EoR in $R_{\rm h}=ct$ when complete structure formation models become available.en
dc.language.isoenen
dc.publisherOXFORD UNIV PRESSen
dc.relation.urlhttp://mnras.oxfordjournals.org/lookup/doi/10.1093/mnras/stv2902en
dc.rights© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Societyen
dc.titleThe epoch of reionization in the R h = ct universeen
dc.typeArticleen
dc.contributor.departmentThe University of Arizonaen
dc.identifier.journalMonthly Notices of the Royal Astronomical Societyen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal accepted manuscripten
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