Chan Man Ho, Lee Chak Man, Yu Chi Wai
Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, New Territories, Hong Kong, China.
Sci Rep. 2022 Sep 10;12(1):15258. doi: 10.1038/s41598-022-18946-7.
In the past three decades, many stars orbiting about the supermassive black hole (SMBH) at the Galactic Centre (Sgr A*) were identified. Their orbital nature can give stringent constraints for the mass of the SMBH. In particular, the star S2 has completed at least one period since our first detection of its position, which can provide rich information to examine the properties of the SMBH, and the astrophysical environment surrounding the SMBH. Here, we report an interesting phenomenon that if a significant amount of dark matter or stellar mass is distributed around the SMBH, the precession speed of the S2 stellar orbit could be 'slow down' by at most 27% compared with that without dark matter surrounding the SMBH, assuming the optimal dark matter scenario. We anticipate that future high quality observational data of the S2 stellar orbit or other stellar orbits can help reveal the actual mass distribution near the SMBH and the nature of dark matter.
在过去三十年里，人们识别出了许多围绕银河系中心超大质量黑洞（人马座A*）运行的恒星。它们的轨道特性能够对超大质量黑洞的质量给出严格限制。特别是，自我们首次探测到恒星S2的位置以来，它已至少完成了一个周期，这能提供丰富信息来检验超大质量黑洞的性质以及超大质量黑洞周围的天体物理环境。在此，我们报告一个有趣的现象：假设存在最佳暗物质情形，若在超大质量黑洞周围分布有大量暗物质或恒星质量，与没有暗物质环绕超大质量黑洞的情况相比，S2恒星轨道的进动速度最多可“减慢”27%。我们预计，未来S2恒星轨道或其他恒星轨道的高质量观测数据将有助于揭示超大质量黑洞附近的实际质量分布以及暗物质的本质。
