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Session 3 - Source Surveys, Galaxy Surveys, Distance Scale I.
Display session, Wednesday, January 07
Exhibit Hall,

[3.14] The HST WFPC2 B-Band Parallel Survey

S. H. Cohen, R. A. Windhorst, C. A. T. C. Burg (ASU), S. C. Odewahn (Caltech), S. P. Driver (UNSW), R. S. de Jong (Durham), R. O. Marzke (DAO), J. A. Tyson, I. Dell'Antonio (Lucent Tech.)

This survey contains 29 shallow (B\lesssim25) randomly selected high latitude WFPC2 fields with images taken in both B(F450W) and I(F814W). The goal of this project is to morphologically classify the galaxies and then study galaxy properties as a function of B-band type. The galaxies are classified using an Artificial Neural Network (ANN) on the higher S/N I-band images which provides reliable types for I\lesssim25 or B\lesssim27 mag. The ANN classification depends on surface brightness and light profile but not on color or scale length. These results are combined with similar (deeper) studies in the HDF and the deep field surrounding the radio galaxy 53W002.

First we present the B-band galaxy counts for early types (E/S0), mid-types (Sabc) and late types (Sd/Irr), along with the total counts. These counts show that we have adequate statistics for a range 19\lesssimB\lesssim27 and that the counts are in good agreement with other studies. The key here is improved statistics at the bright end. It is also evident that the faint portion of the counts is dominated by the irregular galaxies, which have a steep count slope of \alpha\simeq0.40\pm0.05. We also show the relation between magnitude and scale length as a function of type. This, along with the color-magnitude diagram for this sample, shows that there is a general trend with both color and size as a function of morphological type and apparent magnitude. More data is expected and we hope to improve the statistics, especially at the bright end.

Program listing for Wednesday