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Optical spectroscopy of galaxies in the direction of the Virgo cluster
Optical spectroscopy of 76 galaxies, 48 of which are projected in thedirection of the Virgo cluster and 28 onto the Coma-A1367 supercluster,is reported. Adding these new measurements to those found in theliterature, the redshift completeness in the Virgo region becomes 92% atB_T<=16.0 and 68% at B_T<=18.0. The one of CGCG galaxies in thedirection of the Coma-A1367 supercluster becomes 98%. The Virgo clustermembership estimates obtained on morphological grounds by Binggeli etal. (\cite{Binggeli}) are confirmed in all cases. However, several``possible members" classified as BCD (if in the cluster) are foundinstead to be giant emission-line galaxies in the background of theVirgo cluster Based on observations obtained with the Loiano telescopebelonging to the University of Bologna, Italy, with the OHP, operated bythe French CNRS and with the G. Haro telescope of the INAOE, Mexico.
| A Minnesota Automated Plate Scanner Catalog of Galaxies behind the Virgo Cluster and toward Its Antipode
We present a catalog of 1268 galaxies, essentially complete to B <=17.0, found by scanning glass copies of several fields of the originalPalomar Sky Survey using the Minnesota Automated Plate Scanner in itsisodensitometric mode (as opposed to the threshold densitometric modeused in the APS Catalog of the POSS I). In addition to the differentscanning mode, we have employed a different star-galaxy separationmethod and have visually inspected POSS prints to verify that each imageremaining in the catalog is nonstellar. The scanned fields aredistributed generally in two areas, one around the outskirts of theVirgo Cluster, the other toward the antipode of the cluster (but stillin the northern celestial hemisphere). The catalog gives the position ofthe center of each galaxy; estimates of the blue and red magnitudeswithin the outermost threshold crossing and of the blue magnitudeextrapolated to zero surface brightness; and the blue and red diametersof four ellipses fitted to the four threshold crossings (approximately23.8,23.6,23.2, and 22.7 mag arcsec 2 in blue, and 22.5,22.4,21.5, and21.2 mag arcsec^-2^ in red), and the ellipticities of those fourellipses. The catalog has served as a base from which to draw targetsfor a Tully-Fisher study of the Virgocentric infall velocity of theLocal Group.
| Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area.
The present catalog of 2096 galaxies within an area of about 140 sq degapproximately centered on the Virgo cluster should be an essentiallycomplete listing of all certain and possible cluster members,independent of morphological type. Cluster membership is essentiallydecided by galaxy morphology; for giants and the rare class of highsurface brightness dwarfs, membership rests on velocity data. While 1277of the catalog entries are considered members of the Virgo cluster, 574are possible members and 245 appear to be background Zwicky galaxies.Major-to-minor axis ratios are given for all galaxies brighter than B(T)= 18, as well as for many fainter ones.
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