Abstract

We analyze the CS ((Formula presented) –1) line cube from the internal data release obtained by the large-scale program “ALMA CMZ Exploration Survey (ACES)” to investigate the kinematic structure of the innermost (Formula presented) pc region of the Galaxy, which contains the high-velocity compact cloud (HVCC) at (Formula presented) (hereafter G0.02). The longitude–velocity diagram (LVD) of the cloud draws an elliptical structure, which is interpreted as an orbital trajectory in the (Formula presented) space of a noncircular (eccentric) motion of the molecular gas in the gravitational potential of an extended mass distribution in the central (Formula presented) pc of the Galaxy. We argue that G0.02 is a kinematic tracer of the inner potential, a rare case of a dense gas following an eccentric orbit in the nuclear gravitational field. © The Author(s) 2025. Published by Oxford University Press on behalf of the Astronomical Society of Japan. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.