2003MNRAS.341..509L

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 H₂in the Galactic Centre, in a 90x27 arcsec² region between the north-eastern boundary of the non-thermal source Sgr A East, and the giant molecular cloud (GMC) M-0.02-0.07. The detected H₂v = 1 ⟶ 0 S(1) emission has an intensity of 1.6-21x10^–18 W.m^–2.arcsec^–2 and is present over most of the region. Along with the high intensity, the large linewidths (FWHM = 40-70 km.s^–1) and the H₂v = 2 ⟶ 1 S(1) to v = 1 ⟶ 0 S(1) line ratios (0.3-0.5) can be best explained by a combination of C-type shocks and fluorescence. The detection of shocked H₂is clear evidence that Sgr A East is driving material into the surrounding adjacent cool molecular gas. The H₂emission lines have two velocity components at ~+50 and ∼0 km.s^–1, which are also present in the NH₃(3, 3) emission mapped by McGary, Coil & Ho. This two-velocity structure can be explained if Sgr A East is driving C-type shocks into both the GMC M-0.02-0.07 and the northern ridge of McGary et al.