标题： MUSE光谱成像研究Th 28喷流：内喷流的进动 显示英文标题

标题： A MUSE Spectro-imaging Study of the Th 28 Jet: Precession in the Inner Jet

摘要： 上下文：Th 28 是卢pus 3 星云中的一颗经典 T 星，它驱动着一个扩展的双极喷流。 先前对内喷流的研究发现了围绕喷流轴旋转的特征，这是喷流产生理论的一个关键结果。 因此，这是一个重要的天体，用于研究尚不明确的喷流产生机制。 我们利用 VLT/MUSE 获取的光学积分场光谱观测数据，研究 Th 28 微喷流的形态和运动学，以表征其结构和喷流活动。 我们使用光谱成像和位置-速度图来研究喷流的动力学和形态特征，并获得一个包含喷流可见的发射线的目录。 采用 Lucy-Richardson 去卷积程序来区分内微喷流区域的结构。 提取垂直于喷流轴的空间剖面，以拟合喷流宽度、张开角以及喷流轴的变化。 我们确认了之前在红移喷流中识别出的结 HHW$_{2}$，并在每个瓣中首次识别出三个额外的结。 我们还发现来自蓝移微喷流的 [O III]$\lambda$5007 发射，包括最靠近恒星的结。 估计了两侧最内部结的自行运动，并表明新结大约在 10-15 年的时间尺度上被喷射出来。 喷流轴质心在两个微喷流的内部部分显示出点对称的波动，表明进动。 我们利用喷流形状测量进动周期为 8 年，半张开角 < 0.6$^{\circ}$。 这可能为之前报告的旋转特征提供另一种解释。 我们发现喷流形状与由于距离恒星 $\leq$ 0.3 天文单位处的棕矮星伴星引起的进动相容。 显示英文摘要

摘要： Context: Th 28 is a Classical T Tauri star in the Lupus 3 cloud which drives an extended bipolar jet. Previous studies of the inner jet identified signatures of rotation around the outflow axis, a key result for theories of jet launching. Thus this is an important source in which to investigate the poorly understood jet launching mechanism. We investigate the morphology and kinematics of the Th 28 micro-jets with the aim of characterizing their structure and outflow activity, using optical integral-field spectroscopy observations obtained with VLT/MUSE. We use spectro-imaging and position-velocity maps to investigate the kinematic and morphological features of the jet, and obtain a catalogue of emission lines in which the jet is visible. A Lucy-Richardson deconvolution procedure is used to differentiate the structure of the inner micro-jet region. Spatial profiles extracted perpendicular to the jet axis are fitted to investigate the jet width, opening angle and the evolution of the jet axis. We confirm the previously identified knot HHW$_{2}$ within the red-shifted jet and identify three additional knots in each lobe for the first time. We also find [O III]$\lambda$5007 emission from the blue-shifted micro-jet including the knot closest to the star. Proper motions for the innermost knots on each side are estimated and we show that new knots are ejected on an approximate timescale of 10-15 years. The jet axis centroids show a point-symmetric wiggle within the inner portion of both micro-jets indicating precession. We use the jet shape to measure a precession period of 8 years, with a half-opening angle < 0.6$^{\circ}$. This may provide an alternative explanation for the rotation signatures previously reported. We find the jet shape to be compatible with precession due to a brown dwarf companion orbiting at a separation $\leq$ 0.3 au.