CfA Colloquium Schedule Fall 2004
 16 September 2004

16 September 2004

Speaker: Chris Carilli (NRAO)

Title: Radio Astronomical Probes of Cosmic Reionization

Abstract: The epoch of reionization (EoR) corresponds to a 'cosmic phase transition', when the neutral intergalactic medium (IGM) becomes ionized by the first stars and/or AGN. While the discoveries of Gunn-Peterson (GP) absorption troughs in the spectra of the highest redshift QSOs, and large scale polarization of the CMB, have set the first constraints on the EoR, the process of reionization, and the nature of the first luminous objects, remain two of the paramount questions in cosmic structure formation. Moreover, the GP effect is such that observations of this epoch will be difficult at wavelengths shorter than about 1micron. In this talk I will explore studies of the EoR at meter through millimeter wavelengths. I will present recent observations of the dust, molecular gas, and star formation activity in the host galaxies of the highest redshift QSOs (z > 6). These results have interesting implications on the timescale for metal and dust enrichment, on the possibility of co-eval formation of SMBHs and galaxies, and on the process of reionization. I will then discuss future capabilities of low frequency radio astronomy to study the neutral IGM via the HI 21cm line, including imaging and power spectral analyses of large scale structure in emission, and absorption studies toward the first radio loud sources.

Video of the Presentation (Talks can be viewed with RealPlayer. Free download is available from )

References for students:

  1. Loeb and Barkana, Ann. Rev. Astron. Astrophys., 39, 19
  2. Walter et al. Nature, 424, 406
  3. Bertoldi et al. Astron. Astrophys., 406, L55
  4. Carilli et al., New Astro. Rev. (in press), (key project V)


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