A&A Supplement series, Vol. 128, March I 1998, 299-308

Received March 6; accepted July 21, 1997

Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies

Ph. Prugniel and Ph. Héraudeau

Send offprint request: Ph. Prugniel (prugniel@obs.univ-lyon1.fr)
Centre de Recherches Astronomique de Lyon, CNRS, Observatoire de Lyon, F-69561 St-Genis-Laval Cedex, France

Abstract:

We present a catalogue of aperture photometry of galaxies, in UBVRI, assembled from three different origins: (i) an update of the catalogue of Buta et al. (1995) (ii) published photometric profiles and (iii) aperture photometry performed on CCD images.

We explored different sets of growth curves to fit these data: (i) The Sérsic law, (ii) The net of growth curves used for the preparation of the RC3 and (iii) A linear interpolation between the de Vaucouleurs (r^1/4) and exponential laws. Finally we adopted the latter solution.

Fitting these growth curves, we derive (1) the total magnitude, (2) the effective radius, (3) the colour indices and (4) gradients and (5) the photometric type of 5169 galaxies. The photometric type is defined to statistically match the revised morphologic type and parametrizes the shape of the growth curve. It is coded from -9, for very concentrated galaxies, to +10, for diffuse galaxies.

keywords: galaxies: fundamental parameters -- galaxies: general -- galaxies: photometry

• 1. Introduction
• 2. The database of aperture photometry
• 3. Fitting method and homogenisation of the data
• 4. The shape of growth curves
• 5. Derived parameters and comparison with RC3
• 6. Comment on the morphological and photometric classifications
• 7. Conclusion
• References