恒星形成区AFGL 5157的CO同位素分子谱线研究

发布时间：2018-03-12 20:24

  本文选题：星际介质　切入点：云　出处：《天文学报》2013年04期 　论文类型：期刊论文

【摘要】：通过对恒星形成区AFGL 5157进行了24′×24′(12 pc×12 pc)的成图观测,得到了该分子云的~(13)CO(J=1-0)和C~(18)O(J=1-0)云核各自的分布结构和平均物理参数.在云核的边缘位置,同位素丰度比X[(~(13)CO)/(C~(18)O)]约为10,接近于巨分子云的比值.~(13)CO和C~(18)O云核的维里质量小于云核质量,具有引力不稳定性,且C~(18)O云核更易塌缩.C~(18)O分子云核的东北方向和西南方向的分子云柱密度分布分别为1.1×10~(23)×z~(-0.43)和4.6×10~(25)×z~(-0.58),z表示到云核中心的距离.由~(12)CO(J=1-0)高速线翼成份的测量,估计了外流源的质量损失率,求得外向流的质量和速度的关系近似为m∝v~(-1.8).~(13)CO分子云核的恒星形成率为23%,该区域可能受反射星云NGC 1985的触发而正在形成中大质量恒星或者星团.
[Abstract]:The distribution structure and average physical parameters of the cloud nuclei of AFGL 5157 in the star forming region are obtained by means of the 24'脳 24'脳 24'~ (12) PC 脳 12 PC), and the distribution structure and the average physical parameters of the cloud nuclei are obtained, respectively, at the edge of the cloud nuclei. The isotope abundance ratio X is about 10, which is close to the ratio of giant molecular clouds. The virial mass of cloud nuclei is smaller than that of cloud nuclei and has gravitational instability. The density distributions of the molecular cloud column in the northeast direction and southwest direction of the cloud nucleus are 1.1 脳 10 ~ (-23) 脳 Z ~ (-0.43)) and 4.6 脳 10 ~ (10) ~ (25) 脳 Z ~ (-0.58) ~ (z) respectively. The mass loss rate of the efflux source is estimated by the measurement of the component of the wing along the high speed line of the Cnion ~ (12) COJJ _ (1-0), which indicates the distance from the cloud nucleus to the center of the cloud nucleus, and the density distribution of the cloud column in the northeast direction and the southwest direction of the cloud nucleus is 1.1 脳 10 ~ (-23) 脳 Z ~ (-0.43)), respectively. The relationship between the mass and velocity of the outward flow is approximate to m 鈭，

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