CH Galactic Center Survey
We present a map of the 3.3 GHz transitions of the CH molecule toward the Galactic Center region. As one of the primary science projects of the upgraded 12-m radio telescope at the Arecibo Observatory, we observed a 1.5 deg. by 1.5 deg. single-pointing map of the region of all 3 CH hyperfine transitions at this frequency. The beam size of the 12-m telescope at this frequency is approximately 27 arcminutes. We sampled this area at half-Nyquist spacing covering nine
positions across a 3 by 3 grid. We detected the CH line at 3.335 GHz in all nine positions in good agreement with previous observations. We also present the first detections of the 3.264 and 3.349 GHz CH lines across the region. In several positions, the 3.264 GHz line amplitude exceeds the main line by a factor of two, in contrast to what is expected in LTE conditions. We emphasize the performance of the Arecibo 12-m for this study, and motivate future use of this instrument to make a fully sampled survey of the galactic plane with unprecedented sensitivity.