TRIGONOMETRIC PARALLAXES OF MASSIVE STAR-FORMING REGIONS. II. CEP A AND NGC 7538
TRIGONOMETRIC PARALLAXES OF MASSIVE STAR-FORMING REGIONS. II. CEP A AND NGC 7538
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DOI：
10.1088/0004-637x/693/1/406
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发表时间：
2008-11
期刊：
影响因子：
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通讯作者：
L. Moscadelli;Mark J. Reid;K. Menten;A. Brunthaler;X. Zheng;Ye Xu;Ye Xu
中科院分区：
文献类型：
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作者：
L. Moscadelli;Mark J. Reid;K. Menten;A. Brunthaler;X. Zheng;Ye Xu;Ye Xu
我们报告了NGC 7538和Cep A的三角引力，分别对应于2.65+0.12−0.11和0.70+0.04−0.04 kpc的距离。它与NGC 7538的距离远小于它的运动学距离，并将其置于英仙座旋臂中，与Cep A的距离也小于它的运动学距离，并将其置于“本地”旋臂或刺。将距离和自行与观测到的径向速度结合起来，就可以给出恒星形成区的位置和整个空间的运动。我们发现这两个源与圆形银河系轨道有显著的偏差：两个源都显示出与银河系自转相反的大的奇特运动（大于10 km s-1），而NGC 7538有一个类似的奇特运动朝向银河系中心。
We report trigonometric parallaxes for the sources NGC 7538 and Cep A, corresponding to distances of 2.65+0.12−0.11 and 0.70+0.04−0.04 kpc, respectively. The distance to NGC 7538 is considerably smaller than its kinematic distance and places it in the Perseus spiral arm. The distance to Cep A is also smaller than its kinematic distance and places it in the “Local” arm or spur. Combining the distance and proper motions with observed radial velocities gives the location and full space motion of the star-forming regions. We find significant deviations from circular galactic orbits for these sources: both sources show large peculiar motions (greater than 10 km s−1) counter to galactic rotation and NGC 7538 has a comparable peculiar motion toward the Galactic center.