LOW-LUMINOSITY COMPANIONS OF EARLY-TYPE GALAXIES

Optical redshifts of nine low-luminosity companions of early-type giant galaxies have been obtained as part of a study of the small-scale clustering properties of dwarf galaxies. The velocity differences between the low-luminosity companions and the nearest giant are typically less than 300 km s-1 in the case of "field" giants and larger for members of groups of galaxies. We speculate that early-type companions of isolated giant galaxies may be gravitationally bound satellites which can be used as dynamical probes of dark halos, while in groups of galaxies they are free-floating in the general potential well of the group. The spectra of one nucleated dwarf elliptical and two dwarfs of composite dE and BCD morphology show evidence of recent star formation.