Tidal tails around the outer halo globular clusters Eridanus and Palomar 15

Understand

We report the discovery of tidal tails around the two outer halo globular clusters, Eridanus and Palomar 15, based on $gi$-band images obtained with DECam at the CTIO 4-m Blanco Telescope.

• The tidal tails are among the most remote stellar streams presently known in the Milky Way halo.
• Cluster members have been determined from the color-magnitude diagrams and used to establish the radial density profiles, which show, in both cases, a strong departure in the outer regions from the best-fit King profile.
• Spatial density maps reveal tidal tails stretching out on opposite sides of both clusters, extending over a length of $\sim$760 pc for Eridanus and $\sim$1160 pc for Palomar 15.