AAS 205th Meeting, 9-13 January 2005
Session 81 Mapping the Universe
Oral, Tuesday, January 11, 2005, 2:00-3:30pm, Town and Country

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[81.02] The Canada–France Deep Fields–Photometric Redshift Survey: An Investigation of Galaxy Evolution Using Photometric Redshifts

M. Brodwin (JPL/Caltech), S. J. Lilly, C. Porciani (ETH-Zurich), H. J. McCracken (IAP), O. Le Fevre (LAM), D. Crampton (HIA), S. Foucaud (IASF-INAF), P. R. Eisenhardt, D. Stern (JPL/Caltech)

This thesis describes a new deep, wide--field, multi--colour imaging survey, 10 times deeper and 30 times larger than its spectroscopic predecessor, the Canada--France Redshift Survey (CFRS). Highly accurate photometric redshifts, calibrated using hundreds of spectroscopic CFRS galaxies, were measured for tens of thousands of objects, with typical dispersions of only \sigma/(1+z) \la 0.06 to I(AB) = 24 for z \le 1.3.

A new Bayesian method to measure the galaxy redshift distribution is developed. The accuracy of the method, which incorporates the full redshift likelihood function of each galaxy in an iterative analysis, is demonstrated in extensive Monte Carlo simulations. I-band and R-band redshift distributions, required for the deprojection of the convergence power spectrum in weak lensing studies, are presented in various magnitude ranges.

We measure the evolution of galaxy correlations with redshift, a primary observable of the structure formation process, correcting for the dilutive effect of photometric redshift errors on the clustering signal. The high z ~ 3 correlation amplitude seen in this work provides compelling evidence for the biased galaxy formation paradigm. The measured galaxy correlations from 0 \la z \la 3 are in excellent agreement with the findings of the largest, state--of--the--art spectroscopic studies.

For the statistics of the galaxy distribution studied in this thesis, the measurement accuracy is limited by the effect of cosmic variance, whose contribution to the total error budget is dominant. Therefore, future studies will be well served by adopting the photometric redshift approach, the efficiency of which will permit the large areas required to obtain a fair sample of the Universe. One such study, the 8.5 deg2 IRAC Shallow Survey, undertaken with Spitzer in the NOAO Bootes field, will permit a study of the clustering evolution of a mass-selected sample of galaxies between 0 \le z \le 2.

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