The luminosity-diameter relation in normal ellipticals: A tool for environmental effects

We have examined a sample of 150 elliptical galaxies taken from a recent survey (Bursteinet al., 1987) which includes also new CCD photometric data. The fits of total luminosityL versus three different diameter indicators (i.e., the effective diameterD _e, theD _n diameter proposed by Dressleret al. (1987), and the isophotal diameterD ₀ at 25 mag arc sec^–2) had given no sign of environmental effect on such quantities. A comparison with previous results based on lower quality data was carried out in order to check the reliability of different photometries and statical tools used.Our main conclusion is that the luminosity-diameter relation seems to be universal in the range of luminosities spanned by our sample; so environmental effects, if present, must be smaller than observational errors.