A photometric determination of twists in three early-type galaxies

Detailed photometric data have been obtained for three early-type galaxies by using the Cerro Tololo 1.5-m telescope and an SEC television camera. The aim of this photometry is to gain further accurate information on the occurrence of twists in such galaxies; i.e., on any variations with radius of the position angle of the major axes of the isophotes. The results of the photometry are: (1) the finding of no detectable twist within the bulge of the S0 galaxy NGC 5102; (2) confirmation of a substantial twist (about 10 deg) in the inner portion of the E3 galaxy IC 1459; and (3) determination of a moderate twist (about 5 deg) within the E4 galaxy NGC 4697, possibly too small to have been previously detected. If such moderate twists should turn out to be common in elliptical galaxies, the suspicion of triaxiality for most such galaxies would be enhanced.