论文标题
主要序列星吞没子遗迹：锂在哪里？
Sub-stellar engulfment by a main sequence star: where is the lithium?
论文作者
论文摘要
在这项工作中，我们研究了太阳样的主序列（MS）恒星对棕色矮人（BD）的吞噬是否可以显着改变恒星的结构和表面上的LI含量。在三种不同的情况下，我们对具有0.01和0.019 MSUN的BD吞没的BD吞没的3D平滑颗粒流体动力学模拟，在三种不同的情况下，是1 msun和太阳成分的MS星。我们详细研究了相互作用的动力学，以及相互作用类型和BD的相关性，在系统的质量损失，角动量传递以及宿主恒星表面的LI丰度变化方面，在子赛对象的最终命运和宿主星的最终命运中的相关性。我们发现，大多数BD质量在MS Star的密集区域稀释。只有在合并方案中，BD材料的显着比例（40％）才能保留在外层中。我们发现相互作用后，宿主星的表面旋转速度明显增加，范围在25 km/s（放牧碰撞）到50 km/s（合并）之间。我们还发现，由于吞噬的情况，系统（1E-4-1E-3 MSUN）的质量损失很大，在合并的情况下，可能会形成类似磁盘的结构。假设在相互作用期间，宿主恒星的对流包膜的深度均未修改，则发现表面液体丰度的较小变化，并且发现了放牧的碰撞。但是，在合并中，根据BD质量，我们发现了20-30因子的大量LI增强。可以在宿主恒星中观察到这些功能中的一些特征，它们保留了足够长的时间。
In this work, we study whether the engulfment of a brown dwarf (BD) by a solar-like main-sequence (MS) star can significantly alter the structure of the star and the Li content on its surface. We perform 3D Smoothed Particle Hydrodynamics simulations of the engulfment of a BD with masses 0.01 and 0.019 Msun, onto an MS star of 1 Msun and solar composition, in three different scenarios: a head-on collision, a grazing collision, and a merger. We study the dynamics of the interaction in detail, and the relevance of the type of interaction and the mass of the BD on the final fate of the sub-stellar object and the host star in terms of mass loss of the system, angular momentum transfer, and changes in the Li abundance in the surface of the host star. We found that most of the BD mass is diluted in the denser region of the MS star. Only in the merger scenario a significant fraction (40%) of the BD material would remain in the outer layers. We find a clear increase in the surface rotational velocity of the host star after the interaction, ranging between 25 km/s (grazing collision) to 50 km/s (merger). We also find a significant mass loss from the system (1e-4 - 1e-3 Msun) due to the engulfment, which in the case of the merger, may form a circumstellar disk-like structure. Assuming that neither the depth of the convective envelope of the host star nor its mass content are modified during the interaction, a small change in the surface Li abundance in the head-on and grazing collisions is found. However, in the merger we find large Li enhancements, by factors 20-30, depending on the BD mass. Some of these features could be detected observationally in the host star provide they remain long enough time.
