Environmental effects on the structure of the Dwarf Spheroidal Galaxies

Abstract

The central surface brightness ($\mu_V(0)$) of the dwarf spheroidal satellites of our own Galaxy is found to correlate with their distance from the Galactic Center ($R_{GC}$). This observational evidence suggests that environmental effects could strongly influence their structure. This suggestion is further supported by a clear-cut bivariate correlation linking $\mu_V(0)$ to a linear combination of $M_V$, the absolute integrated magnitude, and $R_{GC}$, which seems to be shared also by the M31 spheroidals. Possible implications for the Fundamental Plane of elliptical galaxies and Dark Matter content of dwarf spheroidals are also briefly discussed.Comment: 14 pages, plain TEX, 4 figures soon available via ftp://boas3.bo.astro .it bap/files/ , get bap95-34fig*.ps or http://www.bo.astro.it/ or upon request at [email protected] --accepted by MNRAS-Letter