Abstract
We present a large-scale, interferometric survey of ammonia (1, 1) and (2, 2) toward the Galactic center observed with the Australia Telescope Compact Array. The survey covers. Delta l similar to 1 degrees (similar to 150 pc at an assumed distance of 8.5 kpc) and Delta b similar to 0 degrees.2 (similar to 30 pc) which spans the region between the supermassive black hole Sgr A* and the massive star forming region Sgr B2. The resolution is similar to 20 '' (similar to 0.8 pc) and emission at scales greater than or similar to 2 ' (greater than or similar to 3.2 pc) is filtered out due to missing interferometric short spacings. Consequently, the data represent the denser, compact clouds and disregards the large-scale, diffuse gas. Many of the clumps align with the 100 pc dust ring and mostly anti-correlate with 1.2 cm continuum emission. We present a kinetic temperature map of the dense gas. The temperature distribution peaks at similar to 38 K with a width at half maximum between 18 K and 61 K (measurements sensitive within T-kin similar to 10-80 K). Larger clumps are on average warmer than smaller clumps which suggests internal heating sources. Our observations indicate that the circumnuclear disk similar to 1.5 pc around Sgr A* is supplied with gas from the 20 km s(-1) molecular cloud. This gas is substantially cooler than gas similar to 3-15 pc away from Sgr A*. We find a strong temperature gradient across Sgr B2. Ammonia column densities correlate well with SCUBA 850 mu m fluxes, but the relation is shifted from the origin, which may indicate a requirement for a minimum amount of dust to form and shield ammonia. Around the Arches and Quintuplet clusters we find shell morphologies with UV-influenced gas in their centers, followed by ammonia and radio continuum layers.