发表机构
Technion - Israel Institute of Technology（以色列理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究利用新构建的三维红超巨星模型计算共包层演化中吸积物质角动量随机分量，发现其波动幅度可能数倍于固定轴角动量，易形成间歇性吸积盘并发射摆动喷流，支持喷流在共包层演化中关键作用的观点。
AI 中文摘要
我们使用新构建的三维红超巨星（RSG）恒星模型，该模型还模拟核能产生和光球发射，来计算在共包层演化（CEE）期间，伴星在RSG包层内螺旋吸积的物质的角动量的随机分量。吸积物质具有由RSG包层中的密度梯度和轨道运动产生的固定方向角动量分量。方向随机变化的角动量分量源于剧烈的包层对流。我们不包括CEE期间伴星对RSG包层的影响，并考虑一个未受干扰、不旋转的RSG恒星模型。我们发现波动的角动量幅度可能是固定轴角动量的几倍。吸积物质的总比角动量很容易在中子星和黑洞周围形成间歇性吸积盘，但对于在主序星伴星周围形成吸积盘来说，只是勉强足够或根本不够。我们预期形成的间歇性吸积盘将发射轴方向变化的摆动喷流。我们讨论了CEE和掠包层演化（GEE）中摆动喷流的相关方面，GEE可能先于CEE或完全取代它。研究表明喷流在许多CEE情况下是关键因素，标准的CEE应包括伴星在CEE之前（如GEE期间）、期间和/或离开时发射的喷流。我们的研究支持这一观点并强调摆动喷流的重要性。
英文摘要
We use our newly constructed three-dimensional red supergiant (RSG) stellar model, which also mimics nuclear energy production and photospheric emission, to calculate the stochastic component of the angular momentum of the mass that a companion spiraling within the RSG's envelope accretes during common envelope evolution (CEE). The accreted mass has a fixed-direction angular-momentum component arising from the density gradient in the RSG envelope and orbital motion. The angular momentum component with a stochastically varying direction results from vigorous envelope convection. We do not include the companion's influence on the RSG envelope during the CEE and consider an undisturbed, non-rotating RSG stellar model. We find that the fluctuating angular momentum amplitude can be several times the fixed-axis angular momentum. The total specific angular momentum of the accreted mass easily forms intermittent accretion disks around neutron stars and black holes, but it is only marginally sufficient, or not at all, to form accretion disks around main-sequence stellar companions. The intermittent accretion disks we expect to form will launch wobbling jets with varying axes. We discuss aspects of wobbling jets in the CEE and the grazing envelope evolution (GEE), which might precede the CEE or replace it altogether. Studies have claimed that jets are a crucial ingredient in many cases of CEE, and the standard CEE should include jets that the companion launches, before (like the GEE), during, and/or at the exit from the CEE. Our study supports this claim and emphasizes the importance of wobbling jets.
CommentsAccepted in Publications of the Astronomical Society of the Pacific
