Metal Abundance and Kinematical Properties of M81 Globular Cluster
  System
  In this paper, we presented metal abundance properties of 144 M81 globular
clusters. These globulars consist of the largest globular cluster sample in M81
till now. Our main results are: the distribution of metallicities are bimodal,
with metallicity peaks at [Fe/H]\sim-1.51 and -0.58, and the metal-poor
globular clusters tend to be less spatially concentrated than the metal-rich
ones; the metal-rich globular clusters in M81 do not demonstrate a centrally
concentrated spatial distribution as the metal-rich ones in M31 do; like our
Galaxy and M31, the globular clusters in M81 have a small radial metallicity
gradient. These results are consistent with those obtained based on a small
sample of M81 globular clusters. In addition, this paper showed that there is
evidence that a strong rotation of the M81 globular cluster system around the
minor axis exists, and that rotation is present in the metal-rich globular
cluster subsample, while the metal-poor globular cluster subsample shows no
evidence for rotation. The most significant difference between the rotation of
the metal-rich and metal-poor globular clusters occurs at intermediate
projected galactocentric radii. The results of this paper confirm the
conclusion of Schroder et al. that M81's metal-rich globular clusters at
intermediate projected radii were associated with a thick disk of M81.
