X射线双星天鹅座X-1是历史上第一个含有黑洞候选者的微类星体。在描述微类星体和活动星系核等含有黑洞的天体中发生的过程的理论模型中，磁盘吸积范式占主导地位。然而，到目前为止，还没有可靠的测量这些系统中的磁场。天鹅座X-1磁场的第一次预测是由V. F. Shvartsman完成的。他写道，天鹅座X-1的X射线发射毫秒闪烁证明了黑洞的存在，并指出了磁场在黑洞吸积中的作用。从那时起，有许多人试图寻找天鹅座X-1的磁场，但所有这些努力都只表明了上限。我们的VLT FORS 1 2007年和2008年的观测揭示了系统中存在磁场。我们首次在6个标准差水平上得到了天鹅座X-1光学元件（O-超巨星）表面130 G量级的磁场，并根据理论预言得到了吸积结构外部磁场4 σ水平的观测估计（约600 G）。将这个磁场值标度到黑洞附近，我们发现这个磁场足够强，可以解释X射线毫秒闪烁现象，我们的结果首次直接确定了黑洞吸积盘中的磁场。
英文摘要：
X-ray binary Cygnus X-1 is microquasar containing historically first candidate to black hole. Paradigm of magnetic disc accretion dominates in theoretical models describing processes taking place in objects containing black holes such as microquasars and active galactic nuclei. Nevertheless up to now there were no reliable measurements of magnetic fields in these systems. The first prediction of the Cyg X-1 magnetic field was done by V.F.Shvartsman. He wrote that Cyg X-1 X-ray emission millisecond flickering evidences the presence of a black hole and points to the magnetic field role in accretion onto a black hole. From that times there were many of attempts to search for the Cyg X-1 magnetic field but all of these efforts indicated upper limits only. Our VLT FORS1 2007 and 2008 observations revealed a presence of a magnetic field in the system. For the first time we obtained on the level of 6 standard deviations a magnetic field of the order of 130 G on the surface of the Cyg X-1 optical component (O-supergiant) and observational estimation on a 4 sigma level of a magnetic field on a outer part of accretion structure (about 600 G) in accordance with theoretical prediction. Scaling this field value to black hole vicinity we showed that the field is strong enough to explain the X-ray millisecond flickering and can explain it. Our result presents the first direct determination of magnetic field in accreting disk around a black hole.
The lack of fast rotators in Cyg OB2. I. Insights from spectral reclassification of its B0 population
Instituto de Astrofísica de Canarias（加那利天体物理学研究所）；Departamento de Astrofísica, Universidad de La Laguna（拉帕尔马大学天体物理学系）；Gran Telescopio Canarias (GRANTECAN)（大加那利望远镜）
Confirmation Via the Continuum-Fitting Method that the Spin of the Black Hole in Cygnus X-1 is Extreme
在Gou et al.（2011）中，我们报道了X射线双星天鹅座X-1中的主要黑洞是一个自旋参数a*>0.95（3σ）的近极端克尔黑洞。我们确认了这一结果，同时设定了一个新的更严格的限度：在3σ（99.7%）置信水平下，a*>0.983。早期的工作是基于对所有三个可用光谱的分析，可能是由于这些光谱中存在相对较强的康普顿幂律成分而产生的偏差：散射到幂律中的热种子光子的比例为f_s=23- 31%，而连续拟合方法可靠应用的上限是f_s<25%。随后，我们又获得了天鹅座X-1的六个适合于测量自旋的光谱。其中五个光谱具有高质量，f_s在10%至19%的范围内，连续拟合方法已被证明可以提供可靠的结果。单独地，六个光谱给出了自旋参数的下限，范围从a*>0.95到a*>0.98，使我们能够保守地得出结论，黑洞的自旋是a*>0.983（3σ）。
