Star Formation in Early-Type Virgo Cluster Spiral Galaxies
Session 76 -- Spirals I
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

## [76.14] Star Formation in Early-Type Virgo Cluster Spiral Galaxies

R.A. Koopmann, J.D.P. Kenney (Yale)

The Virgo Cluster has a population of early-type spiral galaxies not present in the field. These galaxies are very HI-deficient and have small star-forming disks. The uncertainty about the nature of these galaxies is reflected in their morphological classifications; many are classified as peculiar or have mixed classifications such as Sc/Sa. An understanding of the origin of these galaxies is crucial in determining the importance of the cluster environment in galaxy evolution.

Much can be learned about the influence of the cluster environment on these galaxies by comparing them to isolated galaxies, which are least affected by environment. Peculiar early-types in the Virgo Cluster may simply be stripped versions of isolated spirals or they may be remnants of tidal interactions or mergers. We present the results of a comparison of the star-forming properties and kinematics of 18 Virgo Cluster early-type spirals and 15 isolated S0, Sa, and Sc spirals, based on analysis of H$\alpha$ and R images and optical long slit spectroscopy. The most spectacular galaxy in this sample is the Sa peculiar NGC 4424, which is