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Session 87 - Large Scale Structure.
Display session, Friday, January 09
Exhibit Hall,
The angular clustering of faint field galaxies is investigated using deep imaging (I\sim 25) obtained with the 10-m Keck--I telescope. The autocorrelation function is consistent with ømega(\theta) \propto \theta^-0.8, and we find no compelling evidence for a flattening of the power law index at the faintest magnitude limits. Results from a number of independent observational studies are combined in order to investigate the variation of the correlation amplitude with median I-magnitude. At I_med\sim 23 the results obtained by different studies are all in rough agreement and indicate that for I_med > 22 the correlation amplitude declines far less steeply than would be expected from an extrapolation of the trend in the brighter samples. In particular, at I_med \sim 24 our data indicate ømega(\theta) to be a factor \sim 7 higher than the extrapolation. A flattening of the correlation amplitude at faint magnitude limits is a general feature of models in which the redshift distribution of the faint field population contains a substantial fraction of objects at z > 1 and in order to reproduce the apparent abrupt flattening of the amplitude of ømega(\theta) observed at the faintest limits, of order 50% of the galaxies in a sample with I_med \sim 24 must be at z > 1.