Jets and Tori in Proto-Planetary Nebulae
Jets and Tori in Proto-Planetary Nebulae
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原行星状星云中的喷流和托里
DOI：
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发表时间：
2007
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通讯作者：
P. Huggins
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文献类型：
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作者：
P. Huggins
我们研究了恒星从渐近巨星分支过渡到行星状星云阶段时喷流和分子环面出现的时间序列。喷流和环面是这种进化的突出特征，但它们的起源尚不确定。利用光学和毫米线运动学，我们确定了弹射历史的一个样本，充分观察的情况下。我们发现射流和环面几乎同时发展。我们还发现，有证据表明，喷流的出现时间通常略晚于tori，滞后时间为几百年。这些特征为射流与环面之间的物理关系提供了强有力的证据，并对射流形成理论提出了新的限制。在短时间尺度上，离散环面抛射后的喷流有利于伴星与中心恒星相互作用的模型。具有长时间尺度的模型，或喷流后面有一个环面的模型，都被排除在外。
We investigate the time sequence for the appearance of jets and molecular tori in the transition of stars from the asymptotic giant branch to the planetary nebula phase. Jets and tori are prominent features of this evolution, but their origins are uncertain. Using optical and millimeter line kinematics, we determine the ejection history in a sample of well-observed cases. We find that jets and tori develop nearly simultaneously. We also find evidence that jets typically appear slightly later than tori, with a lag time of a few hundred years. These characteristics provide strong evidence that jets and tori are physically related, and they set new constraints on theories of jet formation. The ejection of a discrete torus followed by jets on a short timescale favors the class of models in which a companion interacts with the central star. Models with long timescales, or with jets followed by a torus, are ruled out.