Interaction between the Northeastern Boundary of Sgr A East and Giant Molecular Clouds: Excitation Mechanisms of the H2 Emission

Abstract

We have detected the v = 1 0 S(1) (λ = 2.1218 μm) and v = 2 1 S(1) (λ = 2.2477 μm) lines of H2 in a region between the northeastern boundary of Sgr A East and the giant molecular cloud (GMC) M-0.02-0.07, in the Galactic centre. The broad line widths, the low peak velocities relative to the molecular clouds, and the moderate H2 v = 2 1 S(1) to v = 1 0 S(1) line ratios can be best explained by a combination of C-type shocks and .uorescence. The detection of shocked H2 in this region is clear evidence that Sgr A East is driving material into both the GMC M-0.02-0.07 and the northern ridge found by McGary, Coil, & Ho (2001).