A wide-field kinematic survey for tidal tails around five globular clusters

Abstract

Using the AAOmega instrument of the Anglo-Australian Telescope, we have obtained medium-resolution near-infrared spectra of 10,500 stars in two-degree fields centered on the galactic globular clusters 47 Tuc, NGC 288, M12, M30 and M55. Radial velocities and equivalent widths of the infrared Ca II triplet lines have been determined to constrain cluster membership, which in turn has been used to study the angular extent of the clusters. From the analysis of 140-1000 member stars in each cluster, we do not find extended structures that go beyond the tidal radii. For three cluster we estimate a 1% upper limit of extra-tidal red giant branch stars. We detect systemic rotation in 47 Tuc and M55.

4 pages, 3 figures, accepted for publication in ApJ Letters

References in corpus (2)

• Formation and evolution of clumpy tidal tails around globular clusters
• Using globular clusters to test gravity in the weak acceleration regime: NGC 7099

Cited by in corpus (4)

• Halo globular clusters observed with AAOmega: dark matter content, metallicity and tidal heating
• A Spectroscopic Survey for Omega Centauri Members at and beyond the Cluster Tidal Radius
• AAOmega radial velocities rule out current membership of the planetary nebula NGC 2438 in the open cluster M46
• Radial velocities of five globular clusters obtained with AAOmega