A Search for Kinematic Evidence of Tidal Tails in Globular Clusters
Recent star count surveys of areas around globular star clusters have shown strong evidence of tidal tails stretching out many degrees beyond the cluster tidal radius. These tails are believed to be cluster stars which have escaped due to tidal shocking after passages through the disk of the Galaxy. Although the statistical star counts indicate and overdensity of stars around the clusters, to date, there is little kinematic verification for any tidal tail stars.We present results of a kinematic search for evidence of tidal tails using the Sloan Digital Sky Survey (SDSS), Data Release-1 (DR1). This search was conducted using thirteen globular star clusters which were found to be within three degrees of the DR1 strips. Using stars from the DR1 spectroscopy database, we have determined radial velocities, distances and metal abundance for the large number of the SDSS stars. The SDSS stars include horizontal branch stars, blue stragglers and main sequence turn-off stars, most of which reach to the distances of the clusters. Comparing these parameters to that of a given globular cluster, we search for stars which match the cluster parameters to within the uncertainty of our derived parameters. Along with the candidate findings for this project, we will also including a comparison of candidate tidal star positions to that of published tidal tails from star counts, and discuss future refinements and follow-up observations.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2003