SIMBAD references

We investigate the radial dependence of the spectroscopic properties, in particular the Mg₂, <Fe>, and Hβ spectroscopic indices, in a sample of galaxies spanning a wide range of absolute luminosity in the Coma Cluster. After allowing for the magnitude dependence of these indices, we find a significant gradient in Mg₂, in the sense that galaxies in the core of the cluster have stronger Mg₂. We find only weak gradients in <Fe> and Hβ. Using the model grids presented in an earlier paper in this series, we attribute the Mg₂ gradient to changes in metal abundance. One possible mechanism to create this abundance gradient is pressure confinement by the intracluster medium of material from supernova-driven winds early in the history of the galaxies.