The bulk of the stars in the nuclear stellar disk (NSD), at the center of the Milky Way with a radius of ∼200 pc, formed at least 8 Gyr ago. However, the NSD seems to have experienced outstanding star-forming event about 1 Gyr ago, during which roughly 5% of its mass formed in what may arguably have been one of the most energetic events in the history of the Milky Way. This remarkable star-formation history has been suggested from recent high-angular resolution near-infrared images. From spectroscopic studies, however, only a few of such young and intermediate-age stars have been identified in the NSD; the only available list is from recent Subaru observations, which contains 13 intermediate-age stars with shallower CO absorption in their atmosphere. In addition to the spectroscopically age-identified stars, we have obtained 131 candidates of the young and intermediate-age star populations in a 6.′0 × 3.′3 region near Sgr A*, using MOIRCS narrow-band filter sets. In order to identify statistically significant number of young and intermediate-age stars and possibly discuss their spatial distribution, we propose to make spectroscopy of several tens of these 131 candidates.
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