The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. I. Detection of a rich population of dusty objects in the IRS 13 cluster

A detailed analysis of the Nuclear Stellar Cluster (NSC) concedes not only the existence of the Scluster with its fast-moving stars and the supermassive black hole (SMBH) Sgr A*. It also reveals an embedded region of gas and dust with an exceptionally high stellar density called IRS 13. The IRS 13 cluster can be divided into the northern and the eastern counterparts, called IRS 13N and IRS 13E, respectively. This work will focus on both regions and study their most prominent members using rich infrared and radio/submm data baselines. Applying a multiwavelength analysis enables us to determine a comprehensive photometric footprint of the investigated cluster sample. Using the raytracing-based radiative transfer model HYPERION, the spectral energy distribution of the IRS 13 members suggests a stellar nature of the dusty sources. These putative Young Stellar Objects (YSOs) have a comparable spectroscopic identification to the D and G sources in or near the S cluster. Furthermore, we report the existence of a population of dusty sources in IRS 13 that can be mostly identified in the H-, K-, and Lband. Together with the objects reported in literature, we propose that this population is the outcome of a recent star formation process. Furthermore, we report that these presumably young objects are arranged in a disk structure. Although it cannot be excluded that the intrinsic arrangement of IRS 13 does show a disk structure, we find indications that the investigated cluster sample might be related to the counterclockwise disk.
Comment: 59 pages, 44 figures, accepted and published by the ApJ