Mapping the Outer Edge of the Young Stellar Cluster in the Galactic Center

摘要: We present new near-infrared spectroscopic observations of the outer edges young stellar cluster around supermassive black hole at Galactic center. The show a break in surface-density profile stars approximately 13 arcsec (0.52 pc). These spectroscopically confirm previous suggestions based on photometry. Using Gemini North's Near-Infrared Integral Field Spectrometer (NIFS) we are able to detect and separate early- late-type with 75% completeness Ks = 15.5. sample region radii between 7" 23" (0.28 pc 0.92 pc) from Sgr A*, spectral classifications 144 brighter than 15.5, where 140 (> 1 Gyr) only four early-type (young, 4-6 Myr). A broken power-law fit matches well our data previously published values. projected is also measured found be consistent results. find that observed inconsistent theory originating tightly bound infalling cluster, as no significant trail above 13". note either simple disk instability criterion or cloud-cloud collision could explain location edge, though lack information make conclusive remarks alternative. If this represents an edge it would set important scale for most recent episode star formation