The Arcturus moving group is a well-populated example of phase-space substructure within the disk of our Galaxy .
With its large rotational lag ( V = -100 \textrm { kms } ^ { -1 } ) , metal-poor nature ( \textrm { [ Fe / H ] } \sim - 0.6 ) and significant age ( 10 Gyr ) it belongs to the Galaxy ’ s thick disk .
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 .

We confirm via further kinematic studies using the [ Nordström et al .
( 2004 ) , Nordström et al .
( 2004 ) ] , [ Schuster et al .
( 2006 ) , Schuster et al .
( 2006 ) ] and RAdial Velocity Experiment surveys ( RAVE , [ Steinmetz et al .
( 2006 ) , Steinmetz et al .
2006 ] ) the existence of the group , finding it to possibly favour negative U velocities and also possibly a solar-circle phenomenon .
We undertook a high-resolution spectroscopic abundance study of Arcturus group members and candidates to investigate the origin of the group .
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 .

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 .