SDSS red gal. automated morph. classification

Existing automated schemes can successfully distinguish between early- and late-type galaxies and identify merger candidates, but are inadequate for studying detailed morphologies of red sequence galaxies. To fill this need, we present a new automated classification scheme that focuses on making finer distinctions between early types roughly corresponding to Hubble types E, S0 and Sa.

We visually classify a sample of 984 non-star-forming Sloan Digital Sky Survey galaxies with apparent sizes >14-arcsec. We then develop an automated method to closely reproduce the visual classifications, which both provides a check on the visual results and makes it possible to extend morphological analysis to much larger samples. We visually classify the galaxies into three bulge classes (BC) by the shape of the light profile in the outer regions: discs have sharp edges and bulges do not, while some galaxies are intermediate.