Summary

The important results of the previous sections are are summarized below, before discussing in the next section.

1. The group&field dwarf galaxies have a higher surface brightness, at a given total luminosity than cluster dwarfs, in the magnitude range 220#220 to 218#218.

2. The offset is notably larger in the case of early type galaxies than for late type galaxies. In central extrapolated exponential surface brightness 41#41, the field dEs are 222#222 brighter than the cluster dEs, whereas the irregulars are only offset by 223#223.

3. An implication of the abovementioned observation is that the difference in surface brightness between early and late types is larger in the field than in clusters, where the difference is small. The late type galaxies in the group&field are of lower surface brightness and are larger in size than the group&field early types of equivalent absolute magnitude.

4. The difference between the late type group&field dwarfs and the cluster sample late type dwarfs seems to increase with decreasing luminosity, see Table  and Fig.  for the model parameter 41#41. The sense of this increase in the offset is that fainter galaxies in the group&field tend to be of higher surface brightness at a given absolute magnitude than is predicted by the shifted relation. The brighter galaxies, however, show less of an offset between the two environment classes. The slope of the relation defined by the group&field galaxies might therefore be shallower than that defined by the cluster galaxies.

5. In the case of the early type galaxies the trend is opposite to that of the late types, but the difference in offset is small. If real, the trend is that brighter group&field galaxies show a larger offset in surface brightness than the fainter ones. Here the effect is very small, so its significance is not high.

6. There is an offset towards smaller exponential scale length, 139#139, in the case of the group&field sample, as compared to the cluster sample, at a given magnitude. This compensates for the brighter surface brightness at a given magnitude.

7. The difference scale-length between the group&field dwarfs and the cluster dwarfs, for the late types, seems to increase with decreasing luminosity, as in the case of surface brightnesses. The cluster galaxies become larger to compensate for the surface brightness decrease, and this difference increases towards faint magnitudes. The slope defined by the group&field galaxies seems to be steeper than the relation defined by the cluster dwarfs.

8. In the case of the early type dwarfs the trend is opposite to that of the late types, if any. The possible trend is that brighter group&field galaxies show a larger offset towards smaller size than the fainter ones, as compared with their cluster cousins. But again the significance of this trend for the early types is low.