arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1607.01060astro-ph.HE
收藏

自旋对吸积黑洞高能辐射的影响

Effects of Spin on High-Energy Radiation from Accreting Black Holes

Michael O' Riordan, Asaf Pe'er, Jonathan C. McKinney

摘要:

对X射线双星中喷流的观测表明,射电功率与黑洞自旋之间存在相关性。这种相关性如果得到证实,就指向了相对论性喷流可能由黑洞的旋转能量提供动力的想法。为了进一步研究这一点,我们进行广义相对论辐射输运计算磁逮捕吸积流,这是已知的产生强大的喷气机通过Blandford-Znajek(BZ)机制。我们发现,X射线和γ射线的发射强烈依赖于自旋和倾角。令人惊讶的是,高能功率并没有表现出与BZ喷流功率相同的对自旋的依赖性,而是可以理解为红移效应。特别是,垂直于自旋轴观察到的光子在靠近视界之前几乎没有净红移。这样的观察者可以看到更深的炽热、致密、高度磁化的内盘区域。这种效应对于快速旋转的黑洞是最大的,这是由于坐标系拖曳和视界半径减小的共同作用。虽然X射线辐射主要是由近地平线区域,近红外辐射起源于更大的半径。因此,X射线与近红外线能量的比值是黑洞自旋的观测特征。

英文摘要:

Observations of jets in X-ray binaries show a correlation between radio power and black hole spin. This correlation, if confirmed, points towards the idea that relativistic jets may be powered by the rotational energy of black holes. In order to examine this further, we perform general-relativistic radiative transport calculations on magnetically arrested accretion flows, which are known to produce powerful jets via the Blandford-Znajek (BZ) mechanism. We find that the X-ray and gamma-ray emission strongly depend on spin and inclination angle. Surprisingly, the high-energy power does not show the same dependence on spin as the BZ jet power, but instead can be understood as a redshift effect. In particular, photons observed perpendicular to the spin axis suffer little net redshift until originating from close to the horizon. Such observers see deeper into the hot, dense, highly-magnetized inner disk region. This effect is largest for rapidly rotating black holes due to a combination of frame dragging and decreasing horizon radius. While the X-ray emission is dominated by the near horizon region, the near-infrared radiation originates at larger radii. Therefore, the ratio of X-ray to near-infrared power is an observational signature of black hole spin.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑