A new formation scenario of a counter-rotating circumstellar disk: Spiral-arm accretion from a circumbinary disk in a triple protostar system
A new formation scenario of a counter-rotating circumstellar disk: Spiral-arm accretion from a circumbinary disk in a triple protostar system
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反向旋转星周盘的新形成情景：三原恒星系统中双星盘的旋臂吸积
DOI：
10.1093/pasj/psab084
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发表时间：
2021
影响因子：
2.3
通讯作者：
Suto Yasushi
中科院分区：
文献类型：
--
作者：
Takaishi Daisuke;Tsukamoto Yusuke;Suto Yasushi
我们提出了在一个三重原恒星系统模拟从湍流分子云核心没有磁场的星周盘的旋转方向的演变。我们在这样的三重系统中发现了一个新的反旋环星盘的形成途径。第三原恒星的形成是通过环双星盘的碎裂，并且所有三个环星盘的初始旋转方向几乎平行于双星系统的轨道运动方向。它们之间的引力-流体动力相互作用在随后的104 yr极大地扰动了第三星盘的轨道，由于环双星盘的旋臂吸积作用，第三星盘和星星的自转方向发生了逆转。第三纪星周盘的反向旋转一直持续到模拟结束（形成后约6.4 × 104年），这意味着反向旋转盘的寿命很长。这一新的形成途径可能解释了阿尔马最近发现的反向旋转盘。
We present the evolution of rotational directions of circumstellar disks in a triple protostar system simulated from a turbulent molecular cloud core with no magnetic field. We find a new formation pathway of a counter-rotating circumstellar disk in such triple systems. The tertiary protostar forms via the circumbinary disk fragmentation and the initial rotational directions of all three circumstellar disks are almost parallel to that of the orbital motion of the binary system. Their mutual gravito-hydrodynamical interaction for the subsequent ∼104yr greatly disturbs the orbit of the tertiary, and the rotational directions of the tertiary disk and star are reversed due to the spiral-arm accretion of the circumbinary disk. The counter-rotation of the tertiary circumstellar disk continues to the end of the simulation (∼6.4 × 104yr after its formation), implying that the counter-rotating disk is long-lived. This new formation pathway during the disk evolution in Class 0/I young stellar objects possibly explains the counter-rotating disks recently discovered by ALMA.