The Arcturus Moving Group: Its Place in the Galaxy

Abstract

The Arcturus moving group is a well-populated example of phase space substructure within the thick disk of our Galaxy. Traditionally regarded as the remains of a dissolved open cluster, it has recently been suggested to be a remnant of a satellite accreted by our Galaxy. To investigate the origin of the group we undertook a high-resolution spectroscopic abundance study of Arcturus group members and candidates. Examining abundance of Fe, Mg, Ca, Ti, Cr, Ni, Zn, Ce, Nd, Sm and Gd for 134 stars we found that the group is chemically similar to disk stars and does not exhibit a clear chemical homogeneity. Furthermore, we confirm the existence of the Arcturus group using the Nordstroem et al. (2004), Schuster et al. (2006) and RAdial Velocity Experiment (RAVE) surveys (Steinmetz et al. 2006). The origin of the group still remains unresolved: the chemical results are consistent with a dynamical origin but do not entirely rule out a merger one. Certainly, the Arcturus group provides a challenge to our understanding of the nature and origin of the Galaxy's thick disk.

6 pages, 2 figures, to appear in the Proceedings of the IAU Symposium 254: The Galaxy Disk in Cosmological Context

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Cited by in corpus (11)

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• Riding the kinematic waves in the Milky Way disk with Gaia
• Stellar Kinematic Constraints on Galactic Structure Models Revisited: Bar and Spiral Arm Resonances
• Stellar halo streams in the Solar neighbourhood
• Chemo-kinematics of the Milky Way spiral arms and bar resonances: connection to ridges and moving groups in the Solar vicinity
• Chemo-kinematics of the Milky Way from the SDSS-III MARVELS Survey
• Disentangling the Arcturus stream
• Effect of orbital trapping by bar resonances in the local U-V velocity field
• Asymmetric metallicity patterns in the stellar velocity space with RAVE
• Kinematically Detected Halo Streams