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Session 55 - New Digital Sky Surveys.
Display session, Wednesday, June 10
Atlas Ballroom,

[55.05] Morphological Galaxy Counts from the Digitized POSS-II

S. C. Odewahn, S. G. Djorgovski, R. Gal (Caltech), R. R. de Carvalho (Observatorio Nacional, Brasil)

We present preliminary results from a three-color survey of selected high-latitude fields of the digitized Second Palomar Observatory Sky Survey (DPOSS). Innovative automated image classification techniques employing artificial neural network pattern classifiers are used to establish catalogs of stars and galaxies to an approximate magnitude limit of g_J \leq 21 mag. A variety of global photometric properties and Fourier image models are extracted from the JFN galaxy images having diameters measured at the 25 mag\ arcsec^-2 isophote larger than 30''. A multi-dimensional analysis of these quantities is performed using artificail neural networks to develop a viable galaxy morphology classifier for the DPOSS material. We present a new morphological classifiction approach using Fourier image models to identify barred and ringed spiral systems. The resultant multi-color photometric catalog is used to compute morphological galaxy number counts in 3 bands (photographic JFN calibrated to Gunn gri). These data will be compared to predictions from non-evolving and evolving galaxy models and serve as a fiducial measure of galaxy number counts at intermediate flux levels. The results are discussed in the context of related studies of the high redshift Universe made with the Keck telescopes and HST. This work is supported in part by a grant from the Norris Foundation.

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Program listing for Wednesday