2002ApJ...579L..83H

Using the new 23 GHz receivers at the Very Large Array (VLA), we have detected NH₃(6, 6) emission (ν = 25.056025 GHz) from hot (>150 K) molecular clouds in the central 10 pc of the Galaxy. This is the first successful detection of NH₃(6, 6) with the VLA. The brightest emission comes from a region interior to the ``circumnuclear disk'' (CND), less than 1.5 pc in projected distance from Sagittarius A*. This region does not show molecular emission from lower energy transitions such as NH<sub>3</sub>(1, 1) and (2, 2), HCN (1-0), and HCO<sup>+</sup> (1-0). Line ratios of NH<sub>3</sub>(6, 6) and (3, 3) emission as well as NH<sub>3</sub>(6, 6) line widths have peak values within 1.5 pc of Sgr A*, indicating that the gas is physically close to the nucleus. NH<sub>3</sub>(6, 6) is also detected toward many features outside the CND observed in NH<sub>3</sub>(1, 1), (2, 2), and (3, 3). These features tend to lie along ridges of gas associated with Sgr A East or the massive ``molecular ridge'' that connects the ``20 km/s'' and ``50 km/s'' giant molecular clouds.