The Australia Telescope Compact Array H1 survey of the galactic center

We present a survey of atomic hydrogen (H I) emission in the direction of the Galactic Center (GC) conducted with the CSIRO Australia Telescope Compact Array (ATCA). The survey covers the area –5° ≤ l ≤ +5°, –5° ≤ b ≤ +5° over the velocity range –309 km s^–1 ≤ v _LSR ≤ 349 km s^–1 with a velocity resolution of 1 km s^–1. The ATCA data are supplemented with data from the Parkes Radio Telescope for sensitivity to all angular scales larger than the 145" angular resolution of the survey. The mean rms brightness temperature across the field is 0.7 K, except near (l, b) = 0°, 0° where it increases to ~2 K. This survey complements the Southern Galactic Plane Survey to complete the continuous coverage of the inner Galactic plane in H I at ~2' resolution. Here, we describe the observations and analysis of this GC survey and present the final data product. Features such as Bania's Clump 2, the far 3 kpc arm, and small high-velocity clumps are briefly described.