A HIGH-RESOLUTION SURVEY OF H I ABSORPTION TOWARD THE CENTRAL 200 pc OF THE GALACTIC CENTER

We present an H I absorption survey of the central 250 pc of the Galaxy. Very Large Array observations were made at 21 cm in the DnC and CnB configurations and have a resolution of ~15 '' (0.6 pc at the Galactic center (GC) distance) and a velocity resolution of ~2.5 km/s. This study provides H I data with high spatial resolution, comparable with the many high-resolution observations which have been made of GC sources over the past 10 years. Here we present an overview of the HI absorption toward ~40 well-known continuum sources and a detailed comparison of the ionized, atomic, and molecular components of the interstellar medium for the Sgr B, Radio Arc, and Sgr C regions. In these well-known regions, the atomic gas appears to be closely correlated in both velocity and distribution to the ionized and molecular gas, indicating that it resides in photodissociation regions related to the H II regions in the GC. Toward the majority of the radio continuum sources, HI absorption by the 3 kpc arm is detected, constraining these sources to lie beyond a 5 kpc distance in the Galaxy.