The formation of discs in the interior of AGB stars from the tidal disruption of planets and brown dwarfs
The formation of discs in the interior of AGB stars from the tidal disruption of planets and brown dwarfs
复制标题
行星和褐矮星的潮汐破坏导致 AGB 恒星内部圆盘的形成
DOI：
10.1093/mnras/stac463
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发表时间：
2022
影响因子：
4.8
通讯作者：
Blackman, E. G.
中科院分区：
文献类型：
--
作者：
Guidarelli, G.;Nordhaus, J.;Carroll-Nellenback, J.;Chamanady, L.;Frank, A.;Blackman, E. G.
在孤立的白矮星中，有相当一部分拥有超过兆高斯的磁场。观察表明，这些场起源于相互作用的双星系统，在那里伴星被摧毁，从而留下一颗奇特的、高度磁化的白矮星。在后主序演化中，母星的径向膨胀可能会导致轨道伴星被吞没。在共同包络阶段，随着轨道间隔迅速减小，低质量伴星在接近巨星核心时将发生潮汐分裂。我们用流体力学模拟了行星和棕矮星的潮汐分裂，以及随后的吸积盘的形成，在一个渐近的巨型分支恒星的内部。与以前的稳态模拟相比，合成的圆盘的质量分数与估计的大致相同，但还没有达到稳定状态，并且在高度和半径上形态上更长。圆盘的长期演变和其中产生的磁场需要进一步研究。
A significant fraction of isolated white dwarfs host magnetic fields in excess of a MegaGauss. Observations suggest that these fields originate in interacting binary systems where the companion is destroyed thus leaving a singular, highly magnetized white dwarf. In post-main-sequence evolution, radial expansion of the parent star may cause orbiting companions to become engulfed. During the common envelope phase, as the orbital separation rapidly decreases, low-mass companions will tidally disrupt as they approach the giant’s core. We hydrodynamically simulate the tidal disruption of planets and brown dwarfs, and the subsequent accretion disc formation, in the interior of an asymptotic giant branch star. Compared to previous steady-state simulations, the resultant discs form with approximately the same mass fraction as estimated but have not yet reached steady state and are morphologically more extended in height and radius. The long-term evolution of the disc and the magnetic fields generated therein require future study.