New Insights into the 3D Structure and Dynamics of the Canis Major Region

The Canis Major (CMa) region has been the focus of a recent study that provides new insights into its three-dimensional (3D) morphology and the motions of its components. Conducted by Yiwei Dong and colleagues, the research integrates molecular gas data with high-precision astrometric parameters from the Gaia Data Release 3 (DR3) to analyze the dynamical evolution and star formation history of the region.

The study confirms the presence of a slowly expanding shell-like structure in the CMa region, characterized by an estimated radius of 47 ± 11 parsecs and an expansion velocity of 1.6 ± 0.7 kilometers per second. This expansion is supported by a calculated timescale of approximately 4.4 million years, derived from traceback analysis assuming constant velocities.

Furthermore, the authors estimate that at least two supernova explosions are necessary to account for the observed expansion, reinforcing previous hypotheses regarding multiple supernova events in the area. This research effectively combines carbon monoxide (CO) data with astrometric data from young stellar objects (YSOs), paving the way for future studies on the 3D morphology and kinematics of molecular clouds.

The findings of this study are significant as they enhance our understanding of the star formation processes and the dynamic interactions within the Canis Major region, which is crucial for broader astrophysical models. The paper, titled "3D Morphology and Motions of the Canis Major Region from Gaia DR3," can be cited as follows: Yiwei Dong et al., arXiv:2409.01670.