5 Conclusion

  We have presented 210 new central $\mathrm{Mg}_2$ measurements for 87 galaxies rescaled to the Lick/IDS system. The mean individual internal error on these measurements is 0$\hbox{$.\!\!^{\rm m}$}$009$\,\pm\,$0$\hbox{$.\!\!^{\rm m}$}$003 and the external error is 0$\hbox{$.\!\!^{\rm m}$}$012$\,\pm\,$0$\hbox{$.\!\!^{\rm m}$}$002.

Beside providing Mg₂ measurements for 28 new galaxies, this analysis shows the suitability of our spectra for line-strength measurements. We will extend this work by measuring the spatial profiles of line strength indices along the major axis of galaxies, and use this data to go further into the analysis and interpretation of the scaling relations involving the stellar population. Two preliminary reports are published in Prugniel & Golev (1998) and Golev et al. (1998).

Acknowledgements

We are grateful to the telescope operators at Observatoire de Haute-Provence for their help during the observations. This research has made use of the Lyon-Meudon Extragalactic Database (LEDA) operated by the LEDA team at the CRAL-Observatoire de Lyon. This work has benefited from the SIMBAD database operated by the Centre des Données astronomiques de Strasbourg (CDS) in Strasbourg. We acknowledge the use of the ADS Abstract Service. We are grateful to the anonymous referee for useful comments. VG thanks the CRAL-Observatoire Astronomique de Lyon for an invited-astronomer position and the Bulgarian National Science Fundation grant No.F575/1995.