SgrA West in the light of molecules: cold and dense gas east of the circumnuclear disk

摘要

We present the very first detection of N_2H~+ J = (1 - 0) and CH_3OH(2_k-1_k) line emission on 5" scales in the circumnuclear disk (CND) around Sgr A*. The emission matches the position and shape of the dark clouds in the near-infrared. Our findings suggest that these molecular clouds in the eastern CND are significantly colder and denser than the rest of the CND, and partially shocked. The research on these dark clouds will contribute to understanding the processes of star formation close to a supermassive black hole.