Toward an automatic classification of galaxies

The growing quantities of data on galaxies furnished by new instruments are presently addressed by an automatic galaxy-classification method which may be integrated into a data-processing program for photographic plates. The process proceeds through three stages: (1) the digitization of the astronomical field-containing plate in order to detect the galaxies; (2) the extraction of parameters for each galaxy detected; and (3) the use of the parameters to classify the processed image, using an expert system rather than a conventional pattern-recognition algorithm. The current implementation of this system can classify a galaxy in about 122 sec, of which 120 is needed for extraction and 2 for inferential processing. 23 refs