论文标题

恒星形成区域IC 1396N的原始喷气机的NIR光谱调查

NIR spectroscopic survey of protostellar jets in the star forming region IC 1396N

论文作者

Massi, Fabrizio, López, Rosario, Beltrán, Maria T., Estalella, Robert, Girart, Josep M.

论文摘要

简略。明亮的云IC1396N托管Co,h $ _2 $,而Herbig-Haro流出了由毫米紧凑型来源提供动力的。我们的目的是表征h $ _2 $排放特征的运动学和物理条件,分布在IC1396N上,这些功能看起来像带喷射式形态的结链,追踪不同的h $ _2 $流出,并获得有关(和识别)驱动源的进一步信息。使用Grisms KB(R〜1200),HK和JH(R〜500),在TNG处使用NIC在TNG处使用低分辨率,长缝的近红外光谱。在整个IC1396N中使用了几个缝隙指数和PA,以对先前在深H $ _2 $ 2.12 $ 2.12 $μ$ m的图像中检测到的许多H $ _2 $结的样品。这些结表现出富含H $ _2 $的RO振动光谱,与激发激发一致,IC1396N H $ _2 $流出的径向速度和相关的物理条件得出。这些还允许估计几个功能的灭绝范围。 [FEII]仅检测到几个节的发射,这也显示出异常大的H $ _2 $ 1-0 s(3)/s(1)通量比。获得的径向速度证实,大多数流出都靠近天空平面。在同一链中的附近结通常显示出不同的径向速度,蓝色班次和红移,我们认为这是由于驱动源中无处不在的喷气进料或倾斜冲击的发展。其中一个链(链A)作为一组特征,尾随弓形震动结构与3-D磁磁动力学模型的结果一致。领先的弓震(A15)的任何一侧都表现出不同的径向速度,在论文中讨论了可能的解释。我们的数据无法确认链A和B是否都由中间质量年轻恒星对象BIMA 2起源。

Abridged. The bright-rimmed cloud IC1396N hosts CO, H$_2$, and Herbig-Haro outflows powered by millimetre compact sources. We aim to characterise the kinematics and physical conditions of the H$_2$ emission features spread over IC1396N, which appear as chains of knots with a jet-like morphology, tracing different H$_2$ outflows, and to obtain further information about (and an identification of) the driving sources. Low-resolution, long-slit near-infrared spectra were acquired with NICS at the TNG, using grisms KB (R~1200), HK and JH (R~500). Several slit pointings and PA were used throughout IC1396N to sample a number of the H$_2$ knots previously detected in deep H$_2$ 2.12 $μ$m images. The knots exhibit rich ro-vibrational spectra of H$_2$, consistent with shock-excited excitation, from which radial velocities and relevant physical conditions of the IC1396N H$_2$ outflows were derived. These also allowed estimating extinction ranges towards several features. [FeII] emission was only detected towards a few knots, which also display unusually large H$_2$ 1-0 S(3)/S(1) flux ratios. The obtained radial velocities confirm that most of the outflows are close to the plane of the sky. Nearby knots in the same chain often display different radial velocities, both blue-shifted and red-shifted, which we interpret as due to ubiquitous jet precession in the driving sources or the development of oblique shocks. One of the chains (strand A) appears as a set of features trailing a leading bow-shock structure consistent with the results of 3-D magneto-hydrodynamical models. Either side of the leading bow-shock (A15) exhibits a different radial velocity, whose possible explanations are discussed in the paper. Our data cannot confirm whether strands A and B have both been originated by the intermediate mass young stellar object BIMA 2.

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