Optical spectroscopy of galaxies in the direction of the Virgo cluster

G. Gavazzi¹ - C. Bonfanti¹ - P. Pedotti¹ - A. Boselli² - L. Carrasco^3,4

1 - Università degli Studi di Milano - Bicocca, P.zza dell'Ateneo Nuovo 1, 20126 Milano, Italy
2 - Laboratoire d'Astronomie Spatiale, Traverse du Siphon, F-13376 Marseille Cedex 12, France
3 - Instituto Nacional de Astrofísica, Optica y Electrónica, Apartado Postal 51, CP 72000 Puebla, Pue., Mexico
4 - Observatorio Astronómico Nacional/UNAM, Ensenada B.C., Mexico

Abstract:

Optical spectroscopy of 76 galaxies, 48 of which are projected in the direction of the Virgo cluster and 28 onto the Coma-A1367 supercluster, is reported. Adding these new measurements to those found in the literature, the redshift completeness in the Virgo region becomes 92% at $B_{\rm T}\leq16.0$ and 68% at $B_{\rm T}\leq18.0$ . The one of CGCG galaxies in the direction of the Coma-A1367 supercluster becomes 98%. The Virgo cluster membership estimates obtained on morphological grounds by Binggeli et al. (1985) are confirmed in all cases. However, several "possible members" classified as BCD (if in the cluster) are found instead to be giant emission-line galaxies in the background of the Virgo cluster

Key words: galaxies: clusters; virgocluster -- galaxies: distances and redshifts