论文标题

G323.18+0.15中的Cloud-Cloud碰撞和恒星形成

Cloud-cloud collision and star formation in G323.18+0.15

论文作者

Ma, Yingxiu., Zhou, Jianjun., Esimbek, Jarken., Baan, Willem., Li, Dalei., He, Yuxin., Tang, Xindi., Ji, Weiguang., Zhou, Dongdong., Wu, Gang., Xu, Ye.

论文摘要

我们研究了基于诱导的细丝,团块和恒星形成的签名,研究了云云碰撞候选G323.18+0.15。我们使用了来自Sedigism $^{13} $ CO($ j $ \,= \,2--1)调查的档案分子光谱线数据,来自Mopra Southern Galactic Plane CO调查,并从瞥见,MIPS,Hi-Gal和SGPS调查中提供了无线电数据。我们的新结果表明,G323.18+0.15复合物距离我们为3.55kpc,由三个云组件组成,G323.18A,G323.18B和G323.18C。 G323.18B显示出完美的U形结构,可以完全补充G323.18A,这表明G323.18A与联合G323.18BC丝状结构之间发生碰撞。在G323.18B的底部形成一个致密的压缩层(细丝),在那里我们检测到大大增加的速度分散体。位置速度图中具有中间速度的桥梁出现在G323.18A和G323.18B之间,该桥与压缩层相对应。 G323.18A加上G323.18B整体上可能没有重力结合。这表明压缩层中的高质量恒星形成可能是由于意外事件引起的。压缩层中的列密度约为$ 1.36 \ times 10^{22} $ cm $^{ - 2} $,大多数密集的团块和高质量恒星都位于那里。 G323.18+0.15复合物内的分类和年轻恒星物体(YSO)的平均表面密度远高于周围的密度。 G323.18A和G323.18B之间碰撞的时间尺度为$ 1.59 $ MYR。这比分类的典型寿命更长,并且与Classii YSO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.

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