For photometry at very faint levels, fluxes in some bands may even be measured as negative, due to expected sky-subtraction fluctuations. Having different incompleteness limits for each passband further complicates the interpretation of such plots. For the blue, b J is defined by the combination of Eastman IIIa-J emulsion and GG385 filter. For the red, r F is defined by the Eastman IIIa-F emulsion and GG495 filter, and is photometrically intermediate between V and R . The color distribution of nearby galaxies can be determined from a number of relatively bright surveys.
Numbers give sample size.
The dotted histogram in the 20-21 panel is Jones et al. From 22 to 24, Metcalfe et al. Guhathakurta's data are also shown in the 23 - 24 panel as a dotted histogram, for comparison. Shanks et al. This was, however, a model-dependent conclusion that needed spectroscopic redshift confirmation.