Ultradiffuse galaxies in the IC 1459 group from the VEGAS survey
Duncan A. Forbes, Bililign T. Dullo, Jonah S. Gannon, W. J. Couch, E. Iodice, Marilena Spavone, Michele Cantiello, Pietro Schipani
Abstract
ABSTRACT Using deep g, r, i imaging from the VST Early-type GAlaxy Survey (VEGAS), we have searched for ultradiffuse galaxies (UDGs) in the IC 1459 group. Assuming they are group members, we identify nine galaxies with physical sizes and surface brightnesses that match the UDG criteria within our measurement uncertainties. They have mean colours of g − i = 0.6 and stellar masses of ∼108 M⊙. Several galaxies appear to have associated systems of compact objects, e.g. globular clusters. Two UDGs contain a central bright nucleus, with a third UDG revealing a remarkable double nucleus. This appears to be the first reported detection of a double nucleus in a UDG – its origin is currently unclear.