TWO PLANES OF SATELLITES IN THE CENTAURUS A GROUP

摘要

Tip of the red giant branch measurements based on Hubble Space Telescope and ground-based imaging have resulted in accurate distances to 29 galaxies in the nearby Centaurus A Group. All but 2 of the 29 galaxies lie in either of two thin planes roughly parallel with the supergalactic equator. The planes are only slightly tilted from the line of sight, leaving little ambiguity regarding the morphology of the structure. The planes have characteristic rms long axis dimensions of similar to 300 kpc and short axis dimensions of similar to 60 kpc, hence axial ratios similar to 0.2, and are separated in the short axis direction by 303 kpc.