Massive star formation in the Carina nebula complex and Gum 31. I. the Carina nebula complex
Massive star formation in the Carina nebula complex and Gum 31. I. the Carina nebula complex
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船底座星云复合体和 Gum 31 中的大质量恒星形成。 I. 船底座星云复合体
DOI：
10.1093/pasj/psaa078
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发表时间：
2020
影响因子：
2.3
通讯作者：
Fukui Yasuo
中科院分区：
文献类型：
--
作者：
Fujita Shinji;Sano Hidetoshi;Enokiya Rei;Hayashi Katsuhiro;Kohno Mikito;Tsuge Kisetsu;Tachihara Kengo;Nishimura Atsushi;Ohama Akio;Yamane Yumiko;Ohno Takahiro;Yamada Rin;Fukui Yasuo
本文介绍了Mopra和NANTEN2望远镜对船底座星云复合体（CNC）的12co （J= 1-0）、13CO （J= 1-0）和12co （J= 2-1）发射谱线的观测结果。我们重点研究了与CNC相关的大质量恒星形成区域，包括三个星团Tr 14、Tr 15和Tr 16，以及孤立的wr星HD 92740。我们发现CNC中的分子云在- 27，- 20，- 14和- 8 km s - 1的速度下主要分为四个云。它们的质量分别为0.7 × 104M⊙、5.0 × 104M⊙、1.6 × 104M⊙和0.7 × 104M⊙。由于它们的高12CO (J= 2-1)/12CO （J= 1-0）强度比和它们与斯皮策8 μm分布的对应关系，大多数可能与星团有关。此外，这些云显示了云与云碰撞的观测特征。特别是，在位置-速度图中存在一个v形结构，并且在- 20 km s - 1云和- 14 km s - 1云团之间存在互补的空间分布。此外，利用ALMA的存档数据，我们发现碰撞云之间的SiO发射增强，SiO是一种激波分子气体的示踪剂。基于这些观测特征，我们提出了一个场景，其中星团中大质量恒星的形成是由两个云之间的碰撞触发的。通过使用碰撞的路径长度和假设的速度分离，我们估计碰撞的时间尺度为~ 1 Myr。这与先前研究中估计的集群年龄相当。
Herein, we present results from observations of the12CO (J= 1–0),13CO (J= 1–0), and12CO (J= 2–1) emission lines toward the Carina nebula complex (CNC) obtained with the Mopra and NANTEN2 telescopes. We focused on massive-star-forming regions associated with the CNC including the three star clusters Tr 14, Tr 15, and Tr 16, and the isolated WR-star HD 92740. We found that the molecular clouds in the CNC are separated into mainly four clouds at velocities −27, −20, −14, and −8 km s−1. Their masses are 0.7 × 104M⊙, 5.0 × 104M⊙, 1.6 × 104M⊙, and 0.7 × 104M⊙, respectively. Most are likely associated with the star clusters, because of their high12CO (J= 2–1)/12CO (J= 1–0) intensity ratios and their correspondence to the Spitzer 8 μm distributions. In addition, these clouds show the observational signatures of cloud–cloud collisions. In particular, there is a V-shaped structure in the position–velocity diagram and a complementary spatial distribution between the −20 km s−1cloud and the −14 km s−1cloud. Furthermore, we found that SiO emission, which is a tracer of a shocked molecular gas, is enhanced between the colliding clouds by using ALMA archive data. Based on these observational signatures, we propose a scenario wherein the formation of massive stars in the clusters was triggered by a collision between the two clouds. By using the path length of the collision and the assumed velocity separation, we estimate the timescale of the collision to be ∼1 Myr. This is comparable to the ages of the clusters estimated in previous studies.