Abstract details

The nearby Virgo Cluster provides an ideal laboratory to study galaxy-galaxy and galaxy-cluster interactions at a level of detail impossible at higher redshift. In Virgo, there exists a large population of spiral galaxies with mostly undisturbed stellar disks, but truncated gas disks. We present results of an observational study of several of these galaxies, utilizing optical and UV imaging, HI observations and optical spectroscopy. By combining optical spectroscopy and UV imaging, we are able to constrain the time since star formation ended in the outer disk and, therefore, constrain the time since the galaxies were stripped. Our results show that there is a correlation between the time since the end of star formation and the morphologies of the neutral hydrogen gas, in the sense that the outer disks of galaxies with asymmetric HI distributions have only recently stopped forming stars. In the case of the stripped spiral NGC 4522, we find evidence that a modest starburst occurred at the time of stripping, suggesting that stripping events can briefly increase the star formation rate. Finally, while most of the galaxies in our sample are consistent with being stripped near the cluster center, several show evidence for being stripped well outside the core, suggesting that the "reach" of the intracluster medium is greater than is suggested by simple ICM models.