PARALLAXES FOR W49N AND G048.60+0.02: DISTANT STAR FORMING REGIONS IN THE PERSEUS SPIRAL ARM
PARALLAXES FOR W49N AND G048.60+0.02: DISTANT STAR FORMING REGIONS IN THE PERSEUS SPIRAL ARM
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DOI：
10.1088/0004-637x/775/1/79
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
B. Zhang;B. Zhang;M. Reid;K. Menten;X. Zheng;A. Brunthaler;T. Dame;Ye Xu
中科院分区：
文献类型：
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作者：
B. Zhang;B. Zhang;M. Reid;K. Menten;X. Zheng;A. Brunthaler;T. Dame;Ye Xu
我们报告三角视差测量的22 GHz的H2O脉泽在两个巨大的恒星形成区域从甚长基线阵列观测的酒吧和螺旋结构遗产调查的一部分。kpc到W49N（G043.16+0.01）和kpc到G048.60+0.02的距离将它们定位在英仙座臂的遥远部分，靠近银河系第一象限的太阳圈。这使我们能够第一次准确地定位英仙座臂的内部。结合在第二和第三象限的臂外部测得的源，我们得到英仙座臂的全局俯仰角为9.°5 ± 1.°3，在50° <θ < 80°的范围内几乎没有发现H2O脉泽源，这表明在臂的这一600 kpc的部分几乎没有大质量星星形成活动。
We report trigonometric parallax measurements of 22 GHz H2O masers in two massive star-forming regions from Very Long Baseline Array observations as part of the Bar and Spiral Structure Legacy Survey. The distances of kpc to W49N (G043.16+0.01) and kpc to G048.60+0.02 locate them in a distant section of the Perseus arm near the solar circle in the first Galactic quadrant. This allows us to locate accurately the inner portion of the Perseus arm for the first time. Combining the present results with sources measured in the outer portion of the arm in the second and third quadrants yields a global pitch angle of 9.°5 ± 1.°3 for the Perseus arm. We have found almost no H2O maser sources in the Perseus arm for 50° <ℓ < 80°, suggesting that this ≈6 kpc section of the arm has little massive star formation activity.