ALMA Unveils Widespread Molecular Gas Clumps in the Ram Pressure Stripped Tail of the Norma Jellyfish Galaxy
ALMA Unveils Widespread Molecular Gas Clumps in the Ram Pressure Stripped Tail of the Norma Jellyfish Galaxy
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DOI：
10.3847/1538-4357/ab3e6c
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发表时间：
2019-05
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影响因子：
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通讯作者：
P. Jáchym;J. Kenney;M. Sun;F. Combes;L. Cortese;T. Scott;S. Sivanandam;E. Brinks;E. Roediger;J. Palouš;M. Fumagalli
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作者：
P. Jáchym;J. Kenney;M. Sun;F. Combes;L. Cortese;T. Scott;S. Sivanandam;E. Brinks;E. Roediger;J. Palouš;M. Fumagalli
我们提出了首个高分辨率的冷分子气体分布图，这是由ALMA在长冲压压力剥离尾部的CO（2−1）排放所追踪的。Norma星系团星系ESO 137-001正在与周围的星系团内介质发生强烈的相互作用，是最近的具有长多相和多组分尾巴的水母星系之一。我们以1″（350 pc）的角分辨率绘制了尾部的全部范围，并发现大部分致密CO区域的丰富分布，延伸到近60 kpc的长度和25 kpc的宽度。ALMA共检测到109 M⊙的分子气体。通过与先前APEX观测结果的比较，我们还推断出在尾部存在大量延伸的分子成分。ALMA CO的特征主要出现在许多小型（~ 1.5 kpc）火球（即，年轻恒星向星系延伸的线性流的恒星形成云）的头部，以及大型（~ 8 kpc）超级火球和双面火球的头部，这些火球具有额外的扩散电离气体尾巴，向恒星尾巴的相反方向延伸。新的数据有助于揭示分子尾巴的起源；朝向彗尾方向的CO细丝很可能是原位形成的年轻分子特征，而相对于彗尾倾斜的大CO细丝则可能起源于致密的气体复合物，这些气体复合物逐渐被推离盘。
We present the first high-resolution map of the cold molecular gas distribution as traced by CO(2−1) emission with ALMA in a long ram pressure stripped tail. The Norma cluster galaxy ESO 137-001 is undergoing a strong interaction with the surrounding intracluster medium and is one of the nearest jellyfish galaxies with a long multiphase and multicomponent tail. We have mapped the full extent of the tail at 1″ (350 pc) angular resolution and found a rich distribution of mostly compact CO regions extending to nearly 60 kpc in length and 25 kpc in width. In total, about 109 M⊙ of molecular gas was detected with ALMA. From comparison with previous APEX observations, we also infer the presence of a substantial extended molecular component in the tail. The ALMA CO features are found predominantly at the heads of numerous small-scale (∼1.5 kpc) fireballs (i.e., star-forming clouds with linear streams of young stars extending toward the galaxy) but also large-scale (∼8 kpc) superfireballs and double-sided fireballs that have additional diffuse ionized gas tails extending in the direction opposite the stellar tails. The new data help to shed light on the origin of the molecular tail; CO filaments oriented in the direction of the tail are likely young molecular features formed in situ, whereas large CO features tilted with respect to the tail may have originated from dense gas complexes that were gradually pushed away from the disk.