3D simulations of the 180pc molecular ring

Understanding the kinematics and morphology of molecular clouds in the Central Molecular Zone (CMZ) is important for studying the mode of star formation in the central region of the Galaxy. A quasi-continuous ring structure with a radius of 180pc, so-called 180-pc molecular ring, is interpreted as the transition region between the two stable orbits in the bar potential, x1 & x2 [2]. We present, for the first time, 3-D high resolution hydrodynamic simulations of the gas flows in this transition region, and compare the results with previous 2-D studies. We will also see if an m l perturbation, which is revealed as a displacement of the CMZ, is responsible for some of the discrepancies between the previous simulations and observations.