Photometry And Spectroscopy Of Coma Dwarf Ellipticals

Abstract

ies to have (on average) a bluer color: \Delta(B \GammaR)=\DeltaR = \Gamma0:056\Sigma0:002. Fainter than R ' 18:5 mag, the dE sequence spreads and merges with the multitude of noncluster galaxies, which are the dominant population at these magnitudes. The effect is that the program-field mean color values are skewed redward, away from the dashed line (an extension of the upper solid line), towards the mean colors of the control-field objects (open circles). In the right panel of Fig. 1, we plot the binned, scaled and subtracted CMD: one vertical line segment for each color-magnitude bin, with a height proportional to the number of objects in that bin. Here, the solid circles represent the mean corrected color, weighted by the number of objects in each Figure 1: Analysis of the control-field corrected program-field CMD.<F