Details

Autor(en) / Beteiligte

• Pritchard, Jonathan R
• Loeb, Abraham
• Wyithe, J. Stuart B

Titel

Constraining reionization using 21-cm observations in combination with CMB and Ly[alpha] forest data

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2010-10, Vol.408 (1), p.57

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2010

Quelle

Wiley Online Library

Beschreibungen/Notizen

• ABSTRACT In this paper, we explore the constraints on the reionization history that are provided by current observations of the Lyα forest and the cosmic microwave background. Rather than using a particular semi-analytic model, we take the novel approach of parametrizing the ionizing sources with arbitrary functions and perform likelihood analyses to constrain possible reionization histories. We find model-independent conclusions that reionization is likely to be mostly complete byz= 8and that the intergalactic medium was 50 per cent ionized atz= 9-10. Upcoming low-frequency observations of the redshifted 21-cm line of neutral hydrogen are expected to place significantly better constraints on the hydrogen neutral fraction at6 z 12. We use our constraints on the reionization history to predict the likely amplitude of the 21-cm power spectrum and show that observations with the highest signal-to-noise ratio will most likely be made at frequencies corresponding toz= 9-10. This result provides an important guide to the upcoming 21-cm observations. Finally, we assess the impact that measurement of the neutral fraction will have on our knowledge of reionization and the early source population. Our results show that a single measurement of the neutral fraction mid-way through the reionization era will significantly enhance our knowledge of the entire reionization history. [PUBLICATION ABSTRACT]