Observational Test of Environmental Effects on The Local Group Dwarf Spheroidal Galaxies

Abstract

In this paper, we examine whether tidal forces exerted by the Galaxy or M31 have an influence on the Local Group dwarf spheroidal galaxies (dSphs) which are their companions. We focus on the surface brightness profiles of the dSphs, especially their core radii because it is suggested based on the numerical simulations that tidal disturbance can make core radii extended. We examine the correlation for the dSphs between the distances from their parent galaxy (the Galaxy or M31) and the compactnesses of their surface brightness profiles by using a parameter ``C'' defined newly in this paper. Consequently, we find no significant correlation. We make some remarks on the origin of this result by considering three possible scenarios; tidal picture, dark matter picture, and heterogeneity of the group of dSphs, each of which has been often discussed to understand fundamental properties and formation processes of dSphs.

14 pages LaTeX, 2 PostScript figures, to appear in ApJ Letters

References in corpus (6)

• Dwarf Galaxies of the Local Group
• Dwarf Spheroidal Satellite Galaxies Without Dark Matter: Results From Two Different Numerical Techniques
• A Survey for Low-Surface-Brightness Galaxies Around M31. I. The Newly Discovered Dwarf Andromeda V
• Properties of Two New M31 dSph Companions from Keck Imaging
• Physical Interpretation of the Mass-Luminosity Relation of Dwarf Spheroidal Galaxies
• Implication of Dark Matter in Dwarf Spheroidal Galaxies

Cited by in corpus (1)

• The Progenitors of Dwarf Spheroidal Galaxies