Cosmic microwave background constraints on the epoch of reionization

Abstract

We use a compilation of cosmic microwave anisotropy data to constrain the epoch of reionization in the Universe, as a function of cosmological parameters. We consider spatially-flat cosmologies, varying the matter density ${\Omega }_0$ (the flatness being restored by a cosmological constant), the Hubble parameter $h$ and the spectral index $n$ of the primordial power spectrum. Our results are quoted both in terms of the maximum permitted optical depth to the last-scattering surface, and in terms of the highest allowed reionization redshift assuming instantaneous reionization. For critical-density models, significantly-tilted power spectra are excluded as they cannot fit the current data for any amount of reionization, and even scale-invariant models must have an optical depth to last scattering of below 0.3. For the currently-favoured low-density model with ${\Omega }_0=0.3$ and a cosmological constant, the earliest reionization permitted to occur is at around redshift 35, which roughly coincides with the highest estimate in the literature. We provide general fitting functions for the maximum permitted optical depth, as a function of cosmological parameters. We do not consider the inclusion of tensor perturbations, but if present they would strengthen the upper limits we quote.

9 pages LaTeX file with ten figures incorporated (uses mn.sty and epsf). Corrects some equation typos, superseding published version

References in corpus (15)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Discovery of a Supernova Explosion at Half the Age of the Universe and its Cosmological Implications
• The High-Z Supernova Search: Measuring Cosmic Deceleration and Global Cur vature of the Universe Using Type Ia Supernovae
• Constraints on Cosmological Models from Hubble Space Telescope Observations of High-z Supernovae
• Big-bang Nucleosynthesis Enters the Precision Era
• The Cosmic Microwave Background and Observational Convergence in the Omega_m - Omega_lambda Plane
• CMB Anisotropy in the Decaying Neutrino Cosmology
• Cosmological constraints from current CMB and SN 1a data: a brute force 8 parameter analysis
• What Can Cosmic Microwave Background Observations Already Say About Cosmological Parameters in Open and Critical-Density Cold Dark Matter Models?
• Mapping the CMB III: combined analysis of QMAP flights
• Studies of CMB structure at Dec=40. II: Analysis and cosmological interpretation
• Spectral Features from the Reionization Epoch
• The IAC-Bartol Cosmic Microwave Background Anisotropy Experiment: Results of the 1994 Campaign
• New Cosmological Structures on Medium Angular Scales Detected with the Tenerife Experiments
• On The Source of Ionization of The Intergalactic Medium at $z\sim 2.4$

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