Early Evolution of Disk, Outflow, and Magnetic Field of Young Stellar Objects: Impact of Dust Model
Early Evolution of Disk, Outflow, and Magnetic Field of Young Stellar Objects: Impact of Dust Model
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DOI：
10.3847/1538-4357/ab93d0
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
Y. Tsukamoto;M. Machida;H. Susa;H. Nomura;S. Inutsuka
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文献类型：
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作者：
Y. Tsukamoto;M. Machida;H. Susa;H. Nomura;S. Inutsuka
用三维非理想磁流体力学模拟研究了低质量年轻恒星对象(YSO)的形成和早期演化。我们研究了YSO的演化，直到原恒星形成后，即原恒星质量达到的时候。我们特别关注尘埃模型对演化的影响。我们发现，无论是何种尘埃模型，在所有的模拟中都会形成一个环绕恒星的圆盘。圆盘大小在原星形成时期约为10Au，在原星形成后增加到数十Au。圆盘的质量与中心原恒星的质量相当，引力不稳定就会产生。在小尘埃尺寸的模拟中，伪盘的翘曲是在原恒星形成后发展起来的。翘曲加强了磁盘中的磁制动，并减小了磁盘尺寸。当典型的尘埃大小和原恒星(加圆盘)质量时，离子中性漂移可能发生在流入的包层中。沙尘流出活动与沙尘大小成反比，沙尘颗粒较小时出现较强的流出活动。
The formation and early evolution of low-mass young stellar objects (YSOs) are investigated using three-dimensional non-ideal magnetohydrodynamics simulations. We investigate the evolution of YSOs up to after protostar formation, at which protostellar mass reaches . We particularly focus on the impact of the dust model on the evolution. We found that a circumstellar disk is formed in all simulations, regardless of the dust model. Disk size is approximately 10 au at the protostar formation epoch, and it increases to several tens of au at after protostar formation. The disk mass is comparable to the central protostellar mass, and gravitational instability develops. In simulations with small dust sizes, the warp of the pseudodisk develops after protostar formation. The warp strengthens magnetic braking in the disk and decreases disk size. Ion-neutral drift can occur in the infalling envelope when the typical dust size is and the protostar (plus disk) mass is . The outflow activity is anticorrelated to the dust size, and the strong outflow appears with small dust grains.