Discovery of Two Small High-velocity Compact Clouds in the Central 10 pc of Our Galaxy

摘要

We discovered two small high-velocity compact clouds (HVCCs) in the HCN J=4-3 and J=3-2 maps of the central 20 pc of our Galaxy. Both HVCCs have broad velocity widths (Delta V greater than or similar to 40 km s(-1)) and compact sizes (d similar to 1 pc), and originate from the dense molecular clouds in the position-velocity space. One of them has a faint counterpart in a Paschen-a image. Their spatial structure, kinematics, and absence of luminous stellar object are compatible with the notion that each of the small HVCCs is driven by the plunge of an invisible compact object into a molecular cloud. Such objects are most likely inactive, isolated black holes.