AAS 195th Meeting, January 2000
Session 55. Cosmological Parameters and the Early Universe
Oral, Thursday, January 13, 2000, 10:00-11:30am, Regency VII

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[55.06] Reionization as a Probe of Cosmology and Early Astrophysics

A. Venkatesan (University of Chicago)

Observations of high-redshift quasar spectra have revealed that the intergalactic medium is highly ionized up to redshifts of about 5, implying that universal reionization occurred before then. A number of authors have recently investigated reionization by the first stars or quasars through semi-analytic models or numerical simulations. A large number of parameters, both cosmological and astrophysical, describe any specific reionization scenario, e.g, the normalization of the initial power spectrum of density fluctuations, the rate of baryon conversion to stars in early objects, etc. Here, we adopt a semi-analytic model of stellar reionization, quantify how the optical depth to reionization depends on the model's parameters, and combine this with constraints from the microwave background. Given a reionization model, it is also possible to translate limits on cosmological parameters into those on astrophysical parameters, and vice versa.

The author(s) of this abstract have provided an email address for comments about the abstract: aparna@oddjob.uchicago.edu

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