Cloud-cloud collision and star formation in G323.18+0.15
Cloud-cloud collision and star formation in G323.18+0.15
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G323.18 云-云碰撞和恒星形成 0.15
DOI：
10.1051/0004-6361/202243317
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发表时间：
2022-05
影响因子：
6.5
通讯作者：
Xu Ye
中科院分区：
文献类型：
--
作者：
Ma Yingxiu;Zhou Jianjun;Esimbek Jarken;Baan Willem;Li Dalei;He Yuxin;Tang Xindi;Ji Weiguang;Zhou Dongdong;Wu Gang;Xu Ye
基于诱导细丝、团块和恒星形成的特征，我们研究了云-云碰撞候选者G323.18+0.15。我们使用了来自SEDIGISM $^{13}$CO（$J$,=,2- 1）巡天的档案分子谱线数据，来自Mopra南银河面CO巡天的数据，以及来自GLIMPSE、MIPS、Hi-GAL和SGPS巡天的红外到无线电数据。我们的新结果表明，G323.18+0.15复合体距离我们3.55kpc，由G323.18a, G323.18b和G323.18c三个云组件组成。G323.18b呈现完美的u型构造，与G323.18a完全互补，提示G323.18a与合并后的G323.18bc丝状构造发生碰撞。在G323.18b的底部形成了一个致密的压缩层（细丝），在那里我们检测到速度色散大大增加。位置-速度图中出现在G323.18a和G323.18b之间的中间速度桥，对应于压缩层。G323.18a和G323.18b作为一个整体可能不受引力约束。这表明压缩层中的高质量恒星形成可能是由偶然事件引起的。压缩层的柱密度约为1.36 × 10^{22}$cm$^{-2}$，大部分致密团块和大质量恒星都位于此。G323.18+0.15复合体内的i类和i类年轻恒星天体（yso）的平均表面密度远高于周围的密度。G323.18a和G323.18b碰撞的时间尺度为1.59美元。这比i级YSOs的典型寿命更长，并且与i级YSOs的寿命相当。
We studied the cloud-cloud collision candidate G323.18+0.15 based on signatures of induced filaments, clumps, and star formation. We used archival molecular spectrum line data from the SEDIGISM $^{13}$CO($J$,=,2--1) survey, from the Mopra southern Galactic plane CO survey, and infrared to radio data from the GLIMPSE, MIPS, Hi-GAL, and SGPS surveys. Our new result shows that the G323.18+0.15 complex is 3.55kpc away from us and consists of three cloud components, G323.18a, G323.18b, and G323.18c. G323.18b shows a perfect U-shape structure, which can be fully complemented by G323.18a, suggesting a collision between G323.18a and the combined G323.18bc filamentary structure. One dense compressed layer (filament) is formed at the bottom of G323.18b, where we detect a greatly increased velocity dispersion. The bridge with an intermediate velocity in a position-velocity diagram appears between G323.18a and G323.18b, which corresponds to the compressed layer. G323.18a plus G323.18b as a whole are probably not gravitationally bound. This indicates that high-mass star formation in the compressed layer may have been caused by an accidental event. The column density in the compressed layer of about $1.36 times 10^{22}$cm$^{-2}$ and most of the dense clumps and high-mass stars are located there. The average surface density of classI and classII young stellar objects (YSOs) inside the G323.18+0.15 complex is much higher than the density in the surroundings. The timescale of the collision between G323.18a and G323.18b is $1.59$Myr. This is longer than the typical lifetime of classI YSOs and is comparable to the lifetime of classII YSOs.
DOI：
10.1007/978-3-319-22801-3
发表时间：
2018
期刊：
--
影响因子：
--
作者：
S. Stahler
通讯作者：
S. Stahler