A Survey of Radio Recombination Line Emission from the Galactic Center Region

Abstract

Preliminary results of a systematic survey of H78α:, H91α and H98β emission from the inner 40′ of the Galactic center region are presented. This region consists of two prominent continuum features, the Sgr A complex and the radio continuum Arc. In spite of much nonthermal emission arising from these two features, we detected strong line emission with large line widths in more than half of the observed 130 positions. Many of the detections are new, in particular -50 km s-1 ionized gas linking the Sgr A complex and the Arc, s line emission from G0.1+0.08 (the arched filaments), and α line emission from the loop-like structures which surround the non-thermal filaments near G0.2–0.05. We find that much of the detected lines are probably associated with the -50 km s-1and the 20 km s-1 molecular clouds, known to lie near the Galactic center. We present line profiles of a number of Galactic center sources including Sgr B1, Sgr C and Sgr D.