The Pal 5 Star Stream Gaps

Understand

Pal 5 is a low mass, low velocity dispersion, globular cluster with spectacular tidal tails.

• We use the SDSS DR8 data to extend the density measurements of the trailing star stream to 23 degrees distance from the cluster, at which point the stream runs off the edge of the available sky coverage.
• The size and the number of gaps in the stream are measured using a filter which approximates the structure of the gaps found in stream simulations.
• We find 5 gaps that are at least 99% confidence detections with about a dozen gaps at 90% confidence.