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arXiv 1710.03311astro-ph.GAastro-ph.SR
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星际子弹发动机IRAS 05506+2414的分子线研究

A molecular-line study of the interstellar bullet engine IRAS 05506+2414

Raghvendra Sahai, Chin-Fei Lee, Carmen Sanchez Contreras, Nimesh Patel, Mark R. Morris, Mark Claussen

摘要:

我们提出了干涉和单碟分子线观测的星际子弹外流源IRAS 05506+2414,其广角子弹喷雾类似于猎户座BN/KL爆炸外流,可能产生于一个完全不同的机制比经典的吸积盘驱动的双极流在年轻的恒星物体。子弹流出源与一个大的伪盘和三个分子流出-高速流出(HVO),中速流出(MVO),和一个缓慢的,扩展的流出(SEO)。赝盘的大小(质量)为10,350 AU x 6,400 AU(0.64-0.17 Msun);从模型拟合假设的落入和旋转,我们得出的中心恒星质量为8- 19 Msun。HVO(MVO)的角大小为~5180(~3330)AU,预计流出速度为~140 km/s(~30 km/s)。SEO大小(流出速度)为~0.9 pc(~6 km/s)。HVO的轴与SEO(伪盘)的轴对齐(正交)。MVO的速度结构尚未得到解决。HVO和SEO中的标量动量非常相似,这表明SEO是由HVO与周围云物质相互作用引起的。子弹喷射与伪盘共享一个共同的轴,并且具有与MVO相当的年龄(几百年),这表明这三个结构紧密相连。我们讨论了IRAS 05506+2414中外流的几种模型(包括星团的动力学衰变,逃逸恒星与致密云的偶然相遇,以及两颗原恒星的近距离通过),并得出结论,第二历元成像来获得子弹和附近恒星的自行可以帮助区分它们。

英文摘要:

We present interferometric and single-dish molecular line observations of the interstellar bullet-outflow source IRAS 05506+2414, whose wide-angle bullet spray is similar to the Orion BN/KL explosive outflow and likely arises from an entirely different mechanism than the classical accretion-disk-driven bipolar flows in young stellar objects. The bullet-outflow source is associated with a large pseudo-disk and three molecular outflows -- a high-velocity outflow (HVO), a medium-velocity outflow (MVO), and a slow, extended outflow (SEO). The size (mass) of the pseudo-disk is 10,350 AU x 6,400 AU (0.64-0.17 Msun); from a model-fit assuming infall and rotation we derive a central stellar mass of 8--19 Msun. The HVO (MVO) has an angular size ~5180 (~3330) AU, and a projected outflow velocity of ~140 km/s (~30 km/s). The SEO size (outflow speed) is ~0.9 pc (~6 km/s). The HVO's axis is aligned with (orthogonal to) that of the SEO (pseudo-disk). The velocity structure of the MVO is unresolved. The scalar momenta in the HVO and SEO are very similar, suggesting that the SEO has resulted from the HVO interacting with ambient cloud material. The bullet spray shares a common axis with the pseudo-disk, and has an age comparable to that of MVO (few hundred years), suggesting that these three structures are intimately linked together. We discuss several models for the outflows in IRAS 05506+2414 (including dynamical decay of a stellar cluster, chance encounter of a runaway star with a dense cloud, and close passage of two protostars), and conclude that 2nd-epoch imaging to derive proper motions of the bullets and nearby stars can help to discriminate between them.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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