论文标题
在银河中心附近的星形S2轨道中检测Schwarzschild进攻
Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole
论文作者
论文摘要
绕着紧凑型无线电源SGR A*绕的星S2是最接近大型黑洞（候选）的重力场的精确探针。在过去的2.7年中，我们已经监视了恒星在天空上的径向速度和运动，主要是在ESO VLT上的Sinfoni和NACO自适应光学仪（AO）仪器，自2017年以来，具有四型telescope beam beam beam beam组合仪仪表仪。在本文中，我们报告了S2轨道中的一般相对性（GR）Schwarzschild进动（SP）的首次检测。由于其高度椭圆形轨道（E = 0.88），S2的SP主要是运动前后运动前后的扭结〜 + - 1年，相对于相应的开普勒轨道。极好的2017-2019重力天文学定义了上心通道和外向方向。传入方向由S2在红外参考框架中的位置进行118个NACO-AO测量，并在SGR A*的明亮状态（'Flares'）中进行了75个直接测量的S2-SGR A*分离。我们的14参数模型适合距离，中央质量，AO天文学的参考框架相对于质量，轨道的六个参数以及SP的无尺度参数f_sp（Newton的F_SP = 0和GR的1）。从数据到2019年底，我们强劲地检测到S2的SP，DEL PHI = 12'每个轨道周期。从具有不同的加权方案和自举的后拟合和MCMC贝叶斯分析中，我们发现F_SP = 1.10 +-0.19。 S2数据与GR完全一致。 S2轨道内的任何扩展质量都不能超过中央质量的〜0.1％。中央弧秒内的任何紧凑型第三块都必须小于约1000 m_sun。
The star S2 orbiting the compact radio source Sgr A* is a precision probe of the gravitational field around the closest massive black hole (candidate). Over the last 2.7 decades we have monitored the star's radial velocity and motion on the sky, mainly with the SINFONI and NACO adaptive optics (AO) instruments on the ESO VLT, and since 2017, with the four-telescope interferometric beam combiner instrument GRAVITY. In this paper we report the first detection of the General Relativity (GR) Schwarzschild Precession (SP) in S2's orbit. Owing to its highly elliptical orbit (e = 0.88), S2's SP is mainly a kink between the pre-and post-pericentre directions of motion ~ +- 1 year around pericentre passage, relative to the corresponding Kepler orbit. The superb 2017-2019 astrometry of GRAVITY defines the pericentre passage and outgoing direction. The incoming direction is anchored by 118 NACO-AO measurements of S2's position in the infrared reference frame, with an additional 75 direct measurements of the S2-Sgr A* separation during bright states ('flares') of Sgr A*. Our 14-parameter model fits for the distance, central mass, the position and motion of the reference frame of the AO astrometry relative to the mass, the six parameters of the orbit, as well as a dimensionless parameter f_SP for the SP (f_SP = 0 for Newton and 1 for GR). From data up to the end of 2019 we robustly detect the SP of S2, del phi = 12' per orbital period. From posterior fitting and MCMC Bayesian analysis with different weighting schemes and bootstrapping we find f_SP = 1.10 +- 0.19. The S2 data are fully consistent with GR. Any extended mass inside S2's orbit cannot exceed ~ 0.1% of the central mass. Any compact third mass inside the central arcsecond must be less than about 1000 M_sun.
