Distribution and Kinematics of Classical Cepheids in the Galactic Outer Ring

[摘要] The existence of an outer ring in the Galaxy can explain the kinematics of OB associations in the Perseus and Sagittarius stellar-gas complexes. Moreover, it can also explain the orientation of the Carina arm with respect to the major axis of the bar. We show in this paper that the morphological and kinematical features of the sample of classical Cepheids are consistent with the presence of an R 1 R ′ 2 ring in the Galaxy.

[关键词] Galaxy structure Galaxy kinematics and dynamics