2. The sample
The sample is basically the same as in Bottinelli et al. (1995) with the exception that now we include and galaxies which usually are not utilized in TF-distance determinations because of their large scatter. However, when trying to find and understand possible type dependencies, it is important to have the extreme classes in the sample.
During this study it was noticed that the way of determining galaxy type has some influence on the detected type dependence and this led to a revision in how the types are assigned to the galaxies in the LEDA data bank, from which the present galaxies are extracted. We describe the question of types in the future data paper.
As in Bottinelli et al. (1995), we exclude very face-on and edge-on galaxies, allowing the inclination range . Galactic latitudes are omitted and galactic extinction corrections for the diameters are made according to RC2 (de Vaucouleurs et al. 1976). The inclination correction was derived in the above paper: . As we rely on the Virgo-centric velocity field model to derive the kinematical distances, galaxies closer than about from Virgo cannot be used. The final sample contains 3560 galaxies.
© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998