2008ApJ...674..247L

We have obtained velocity-resolved spectra of the H₂1-0 S(1) (λ=2.1218 µm) emission line at 2" angular resolution (or ∼0.08 pc spatial resolution) in four regions within the central 10 pc of the Galaxy where the supernova-like remnant Sgr A East is colliding with molecular clouds. To investigate the kinematic, physical, and positional relationships between the important gaseous components in the center, we compared the H₂ data cube with previously published NH₃data. The projected interaction boundary of Sgr A East is determined to be an ellipse with its center offset ∼1.5 pc from Sgr A* and dimensions of 10.8 pcx7.6 pc. This H₂ boundary is larger than the synchrotron emission shell but consistent with the dust ring, which is believed to trace the shock front of Sgr A East. Since Sgr A East is driving shocks into its nearby molecular clouds, we can determine their positional relationships using the shock directions as indicators. As a result, we suggest a revised model for the three-dimensional structure of the central 10 pc. The actual contact between Sgr A East and all of the surrounding molecular material, including the circumnuclear disk and the southern streamer, makes the hypothesis of infall into the nucleus and feeding of Sgr A* very likely.