Circum-nuclear eccentric gas flow in the Galactic Center revealed by ALMA CMZ Exploration Survey (ACES)
Yoshiaki Sofue, Tomoharu Oka, Steven N. Longmore, Daniel Walker, Adam Ginsburg, Jonathan D. Henshaw, John Bally, Ashley T. Barnes, Cara Battersby, Laura Colzi, Paul Ho, Izaskun Jimenez-Serra, J. M. Diederik Kruijssen, Elizabeth Mills, Maya A. Petkova, Mattia C. Sormani, Jennifer Wallace, Jairo Armijos-Abendaño, Katarzyna M. Dutkowska, Rei Enokiya, Pablo García, Savannah Gramze, Christian Henkel, Pei-Ying Hsieh, Yue Hu, Katharina Immer, Yuhei Iwata, Janik Karoly, Ralf S. Klessen, Kotaro Kohno, Mark R. Krumholz, Dani Lipman, Mark R. Morris, Francisco Nogueras-Lara, Jaime E. Pineda, Sergio Martín, Miguel Angel Requenatorres, Víctor M. Rivilla, Denise Riquelme-Vásquez, Álvaro Sánchez-Monge, Miriam G. Santa-Maria, Howard A. Smith, Volker Tolls, Q. Daniel Wang
We analyze the CS (J=2-1) 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 pc region of the Galaxy, which contains the high-velocity compact cloud (HVCC) at (hereafter G0.02). The longitude-velocity diagram (LVD) of the cloud draws an elliptical structure, which is interpreted as an orbital trajectory in the space of a noncircular (eccentric) motion of the molecular gas in the gravitational potential of an extended mass distribution in the central 10 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.