12 GHz methanol maser outflow from the massive star-forming region: G35.20–0.74
12 GHz methanol maser outflow from the massive star-forming region: G35.20–0.74
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DOI：
10.1088/1674-4527/13/7/005
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发表时间：
2013-07
影响因子：
1.8
通讯作者：
Q. Yan;Bo Zhang;Zheng-hong Tang;Xing-wu Zheng
中科院分区：
文献类型：
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作者：
Q. Yan;Bo Zhang;Zheng-hong Tang;Xing-wu Zheng
本文报道了用甚长基线阵（VLBA）观测的大质量恒星形成区G35.20-0.74中12 GHz甲醇脉泽的内部自行，观测时间为1.5年。探测到两组脉泽特征，A组和B组，后者具有V形空间分布，可能追踪G35.20-0.74的北流出。我们提出了一个三维模型，这些脉泽的运动学，通过假设星际介质被吹的恒星风从驱动源（G35.2N）的流出。采用先前研究中流出物主轴的位置角为0.81 °，我们估计出倾角为35° ± 5.5°，沿着主轴的恒星风速度为8.1 ± 0.7 km s−1，膨胀速度梯度为0.05 ± 0.016 km s−1 Au−1。根据该模型，求得G35.20-0.74期北向外流的年龄为1.6 × 104 yr。
We report the internal proper motions of 12 GHz methanol masers in massive star-forming region G35.20–0.74 observed with the Very Long Baseline Array (VLBA) at four epochs spanning about 1.5 yr. Two groups of maser features were detected, groups A and B, and the latter that had a V-shaped spatial distribution is likely tracing the north outflow in G35.20–0.74. We present a three-dimensional model for the kinematics of these masers, by assuming the interstellar medium was blown by the stellar wind from the driving source (G35.2N) of the outflow. Adopting a position angle of ∼ 81° for the main axis of the outflow from previous studies, we estimate an inclination of 35° ± 5.5°, a velocity of 8.1 ± 0.7 km s−1 for the stellar wind along the main axis and an expansion speed gradient of 0.05 ± 0.016 km s−1 AU−1. From the model, we derive the age of the north outflow in G35.20–0.74 to be ∼ 1.6 × 104 yr.