THE STRANGE BARRED SPIRAL GALAXY ESO 235-58 - A CASE OF MORPHOLOGICAL DECEPTION

On the SRC-J southern sky survey, the galaxy ESO 235-58 (alpha = 21h03m, delta = -48-degrees-19', 1950) looks deceptively like a late-type barred spiral with a weak, broken ring surrounding the bar. However, the bar shows a straight, splitting dust lane, atypical of normal bars but just like what is seen in an edge-on spiral galaxy. In this paper, we use CCD images to show that the apparent bar is indeed likely to be an edge-on galaxy, possibly of Hubble type Sb. The object is part of a group of nine galaxies at a distance of 47 Mpc, and from the photometry we find that the edge-on component has a low luminosity, corresponding to a corrected absolute blue magnitude of M0B = -18.0 (for H-0 = 100). The outer spiral part is asymmetric and may be perturbed by one or both of the neighboring large spirals ESO 235 - 55 and ESO 235 - 57. Since we can find no evidence for an independent bulge or nucleus of this part, we believe that ESO 235 - 58 is not simply a case of superposition of two unrelated objects, but instead is an interacting galaxy of the type related to polar rings. This interpretation is supported by preliminary single-dish H I observations and published optical spectroscopy. Here we present mainly B-band images, a B-I color index map, an unsharp-masked image, integrated parameters, and luminosity profiles of the object to highlight its structural properties.