Measuring spin of a supermassive black hole at the Galactic Centre - Implications for a unique spin
Measuring spin of a supermassive black hole at the Galactic Centre - Implications for a unique spin
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DOI：
10.1111/j.1745-3933.2010.00818.x
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发表时间：
2009-06
影响因子：
--
通讯作者：
Y. Kato;M. Miyoshi;R. Takahashi;H. Negoro;R. Matsumoto
中科院分区：
文献类型：
--
作者：
Y. Kato;M. Miyoshi;R. Takahashi;H. Negoro;R. Matsumoto
我们确定的背景下discseismology的超大质量黑洞的自旋通过比较新检测到的准周期振荡（QPOs）的无线电发射在银河系中心，人马座A*（Sgr A*），以及红外和X射线辐射与银河系黑洞。我们发现Sgr A* 和银河系X射线源中黑洞的自旋参数有一个独特的值--0：44，这个值小于一般公认的超大质量黑洞的值，这表明黑洞在超大质量黑洞生长过程中的角动量提取的证据。我们的研究结果表明，自旋参数接近平衡值，其中通过吸积的自旋上升是平衡的自旋下降通过Blandford-Znajek机制，无论其初始自旋。我们预计，通过使用QPO测量黑洞的自旋将为探索宇宙中黑洞的演化打开一个新的窗口。
We determine the spin of a supermassive black hole in the context of discseismology by comparing newly detected quasi-periodic oscillations (QPOs) of radio emission in the Galactic centre, Sagittarius A* (Sgr A*), as well as infrared and X-ray emissions with those of the Galactic black holes. We find that the spin parameters of black holes in Sgr A* and in Galactic X-ray sources have a unique value of � 0:44 which is smaller than the generally accepted value for supermassive black holes, suggesting evidence for the angular momentum extraction of black holes during the growth of supermassive black holes. Our results demonstrate that the spin parameter approaches the equilibrium value where spin-up via accretion is balanced by spin-down via the Blandford-Znajek mechanism regardless of its initial spin. We anticipate that measuring the spin of black holes by using QPOs will open a new window for exploring the evolution of black holes in the Universe.