A Collimated Jet and an Infalling-Rotating Disk in G192.16−3.84 Traced by H2O Maser Emission
A Collimated Jet and an Infalling-Rotating Disk in G192.16−3.84 Traced by H2O Maser Emission
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DOI：
10.1093/pasj/58.5.883
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发表时间：
2006-08
影响因子：
2.3
通讯作者：
H. Imai;T. Omodaká;T. Hirota;T. Umemoto;K. Sorai;T. Kondo
中科院分区：
文献类型：
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作者：
H. Imai;T. Omodaká;T. Hirota;T. Umemoto;K. Sorai;T. Kondo
本文报道了日本VLBI新观测网在两个月内对G192.16−3.84恒星形成区的三个历元观测的H2O脉泽，揭示了G192.16−3.84整个H2O脉泽区的三维运动学结构，其中包含两个相距约1200天文单位的年轻天体。脉泽的空间运动学结构已经很好地坚持，因为以前的观测，其中的脉泽预计将与一个高度准直的双极喷流和一个下降旋转盘在北方和南部集群的H2O脉泽功能，分别。我们估计喷流的扩张速度为100 kms −1，并重新估计整个喷流的动力年龄为5.6 × 104年。我们研究了在过去和现在的观测中多普勒速度的空间分布和在南部星团中的H2O脉泽特征的相对自行，以及两个脉泽星团之间的相对整体运动。它们可以用一个半径为1000天文单位，中心恒星质量为5-10 M ²的下沉旋转盘模型来很好地解释，而不是用一个垂直于观测到的CO流出的双极喷流模型。根据导出的H2O脉泽空间运动学参数，讨论了G192.16−3.84中大质量年轻天体的形成机制和外流发展。
We report on H2O masers associated with the massive-star forming region G192.16−3.84 observed with the new Japanese VLBI network at three epochs spanned for two months, which have revealed the three-dimensional kinematical structure of the whole H2O maser region in G192.16−3.84, containing two young stellar objects separated by ∼ 1200AU. The maser spatio–kinematical structure has well persisted since previous observations, in which the masers are expected to be associated with a highly collimated bipolar jet and an infalling-rotating disk in the northern and southern clusters of H2O maser features, respectively. We estimated a jet expansion speed of ∼ 100kms −1 and re-estimated the dynamical age of the whole jet to be 5.6 ×10 4 yr. We investigated the spatial distribution of the Doppler velocities during the previous and present observations and the relative proper motions of H2O maser features in the southern cluster, as well as the relative bulk motion between the two maser clusters. They are well explained by a model of an infalling-rotating disk with a radius of ∼ 1000AU and a central stellar mass of 5–10 M� , rather than by a model of a bipolar jet perpendicular to the observed CO outflow. Based on the derived H2O maser spatio–kinematical parameters, we discuss the formation mechanism of the massive young stellar objects and the outflow development in G192.16−3.84.