Surface Brightness Profiles of Three New Dwarf Spheroidal Companions to M31

摘要

CCD images of three newly discovered dwarf spheroidal companions to M31, Andromeda V, VI, and VII, are used to extract surface brightness profiles and total magnitudes. Using distance moduli provided by Armandroff et al. and Grebel & Guhathakurta, these galaxies are shown to have similar luminosities to other Local Group dwarf spheroidals; And V in particular is similar to Draco and Ursa Minor in luminosity, i.e., among the faintest known. In the luminosity-metallicity relation, And V is shown to have a significantly higher metallicity than expected.