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

arXiv · 2506.11553

Circum-nuclear eccentric gas flow in the Galactic Center revealed by ALMA CMZ Exploration Survey (ACES)

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Abstract

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 $\sim 10$ pc region of the Galaxy, which contains the high-velocity compact cloud (HVCC) at $(l,b,v_{\rm lsr})\sim(+0^\circ.02,-0^\circ.02, 100 {\rm km~s}^{-1})$ (hereafter G0.02). The longitude-velocity diagram (LVD) of the cloud draws an elliptical structure, which is interpreted as an orbital trajectory in the $(l,V_{\rm lsr})$ 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.

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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. 2025-06-13. Circum-nuclear eccentric gas flow in the Galactic Center revealed by ALMA CMZ Exploration Survey (ACES). https://arxiv.org/abs/2506.11553

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