2 Description of the method of measurement

Using approximate coordinates of the galaxies to be measured, DSS images are extracted from ESO in Münich. The size of frames is $5' \times 5'$ for galaxies larger than 0.9 arcmin and $3' \times 3'$ for smaller galaxies. If the galaxy is clearly identified, the position of the galaxy center is estimated visually and the corresponding pixel position (X and Y) is interactively determined and converted into Right Ascension and Declination using the polynomial astrometric plate solution given in the header of the FITS file.