VLA OBSERVATIONS OF NEUTRAL HYDROGEN IN VIRGO CLUSTER GALAXIES .1. THE ATLAS

H I maps, velocity fields, position velocity plots, mosaics of the line channel, and H I profiles are presented for the 25 brightest spiral galaxies located in the center of the Virgo Cluster. A synthetic map presents the maps of all the individual galaxies. It confirms that the galaxies located within 3° of M87 have H I disks that are significantly smaller than the optical disks. Further away a number of galaxies have a very asymmetric H I distribution and a sharp edge on the side which points toward M87. The anemic galaxies usually show a ring structure and a patchy aspect. Several gas-rich dwarf galaxies have been found close to H I deficient galaxies and one has been found close to the cluster center. The galaxies located in the western part are larger than in the eastern part. Furthermore the most severely stripped spirals show signs of strong asymmetries in their gas distribution combined with enhanced star formation at the compressed side of the gas disk. This might suggest that we see in the Virgo Cluster a mild form of ram-pressure enhanced star formation, thought to be an important porcess in clusters at higher redshifts.