Key points are not available for this paper at this time.
We identify six ultra-diffuse galaxies (UDGs) outside clusters in three nearby isolated groups (0.014 250 kpc) of our three groups, we identify a population of potential UDG progenitors (two of them confirmed spectroscopically). These progenitors have similar masses, shapes and sizes but are bluer, g − i ∼ 0.45 and for this reason brighter, μg(0) 24 mag arcsec−2 UDGs after ∼6 Gyr. If confirmed, our observations support a scenario where UDGs are old, extended, low surface brightness dwarf galaxies (M⋆ ∼ 108 M⊙) born in the field, are later processed in groups and, ultimately, infall into galaxy clusters by group accretion.
Román et al. (Mon,) studied this question.