本文選題：星際介質(zhì)　切入點：云　出處：《天文學報》2013年04期 　論文類型：期刊論文

【摘要】：通過對恒星形成區(qū)AFGL 5157進行了24′×24′(12 pc×12 pc)的成圖觀測,得到了該分子云的~(13)CO(J=1-0)和C~(18)O(J=1-0)云核各自的分布結構和平均物理參數(shù).在云核的邊緣位置,同位素豐度比X[(~(13)CO)/(C~(18)O)]約為10,接近于巨分子云的比值.~(13)CO和C~(18)O云核的維里質(zhì)量小于云核質(zhì)量,具有引力不穩(wěn)定性,且C~(18)O云核更易塌縮.C~(18)O分子云核的東北方向和西南方向的分子云柱密度分布分別為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離.由~(12)CO(J=1-0)高速線翼成份的測量,估計了外流源的質(zhì)量損失率,求得外向流的質(zhì)量和速度的關系近似為m∝v~(-1.8).~(13)CO分子云核的恒星形成率為23%,該區(qū)域可能受反射星云NGC 1985的觸發(fā)而正在形成中大質(zhì)量恒星或者星團.
[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，

本文編號：1603151