In several simulation runs, we identified star particles aged 20–30 Myr in the NSD and traced their motions to 100 Myr ago, when they existed as gas clouds. At $\sim 75$ Myr before star formation, i.e. during the gas cloud phase, some of the tracked particles had reached the CMZ while others were moving along the bar. However, all these clouds were trapped within the CMZ at the time of star formation. Star formation was scarce along the bar but common within the CMZ, consistent with the simulations of @Kim-2011.

Summary
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We conducted infrared spectroscopic observations of classical Cepheids near the Galactic Center. From the measured radial velocities of the Cepheids, we inferred that they orbit within the NSD in a manner similar to other contained objects. Preliminary simulation suggested that these Cepheids formed in the same disk region 20–30 Myr ago and may have undergone several rotations, rather than becoming trapped in the disk after birth. The orbits of the Cepheids should be further investigated once the proper motions become available, and a detailed study on their kinematics would provide important clues on stellar formation and dynamical evolution in the NSD region. Furthermore, by investigating the chemical abundance 