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arXiv 2107.04830gr-qcastro-ph.HE
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Vlasov气体从有限半径球到黑洞的吸积和angular momentum的作用

Accretion of a Vlasov gas on to a black hole from a sphere of finite radius and the role of angular momentum

Aldo Gamboa, Carlos Gabarrete, Paola Domínguez-Fernández, Darío Núñez, Olivier Sarbach

摘要:

本文分析了球对称无碰撞动力学气体云在Schwarzschild黑洞上的吸积。而以前的研究已经处理这个问题,指定边界条件在无穷远,在这里的性质的气体是在一个球体的有限半径。相应的稳态解是使用四种不同的模型计算的,这些模型的复杂程度越来越高,从牛顿粒子的纯径向下落开始,最终以完全广义相对论计算结束,其中单个粒子具有角动量。由此产生的质量吸积率进行了分析,并与以前的模型,包括标准的邦迪模型的流体动力学流动。我们将我们的模型应用到超大质量黑洞Sgr A* 和M87*,我们讨论了如何可以部分地解释它们的低光度的动力学描述涉及角动量。此外,我们得到的结果与以前的模型相关的边界所施加的旋转措施的偏振光来自Sgr A* 和估计的吸积率M87* 从事件视界望远镜合作的吸积率。我们的方法和结果可以作为一个更现实的黑洞吸积模型在各种天体物理的情况下,吸积的材料预计将是几乎无碰撞的第一近似。

英文摘要:

The accretion of a spherically symmetric, collisionless kinetic gas cloud on to a Schwarzschild black hole is analysed. Whereas previous studies have treated this problem by specifying boundary conditions at infinity, here the properties of the gas are given at a sphere of finite radius. The corresponding steady-state solutions are computed using four different models with an increasing level of sophistication, starting with the purely radial infall of Newtonian particles and culminating with a fully general relativistic calculation in which individual particles have angular momentum. The resulting mass accretion rates are analysed and compared with previous models, including the standard Bondi model for a hydrodynamic flow. We apply our models to the supermassive black holes Sgr A* and M87*, and we discuss how their low luminosity could be partially explained by a kinetic description involving angular momentum. Furthermore, we get results consistent with previous model-dependent bounds for the accretion rate imposed by rotation measures of the polarised light coming from Sgr A* and with estimations of the accretion rate of M87* from the Event Horizon Telescope collaboration. Our methods and results could serve as a first approximation for more realistic black hole accretion models in various astrophysical scenarios in which the accreted material is expected to be nearly collisionless.

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。

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