Giant galaxy growing from recycled gas : ALMA maps the circumgalactic molecular medium of the Spiderweb in [C I]
Giant galaxy growing from recycled gas : ALMA maps the circumgalactic molecular medium of the Spiderweb in [C I]
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DOI：
10.1093/mnrasl/sly034
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发表时间：
2018-02
影响因子：
4.8
通讯作者：
B. Emonts;M. Lehnert;H. Dannerbauer;C. Breuck;M. Villar-Martin;G. Miley;J. Allison;B. Gullberg;N. Hatch;P. Guillard;M. Mao;R. Nrao;Iap;Iac;Eső;CAB-INTA-CSIC;L. Observatory;U. Sydney;D. Univ.;U. Nottingham;U. Manchester;CASSUniv. Western Sydney
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文献类型：
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作者：
B. Emonts;M. Lehnert;H. Dannerbauer;C. Breuck;M. Villar-Martin;G. Miley;J. Allison;B. Gullberg;N. Hatch;P. Guillard;M. Mao;R. Nrao;Iap;Iac;Eső;CAB-INTA-CSIC;L. Observatory;U. Sydney;D. Univ.;U. Nottingham;U. Manchester;CASSUniv. Western Sydney
大质量蛛网星系的环星系介质（CGM）是z = 2.2的合并原星系团星系的聚集体，形成了一个丰富的界面，反馈和再循环作用于吸积气体。这是由阿塔卡马大型毫米波阵列和澳大利亚望远镜紧凑阵列对[CI]、CO（1-0）和CO（4-3）的观测所显示的。[CI]和CO（4-3）在1050 kpc范围内被探测到，这是先前探测到的低表面亮度CO（1-0）在CGM范围内的分布。这证实了我们先前关于冷分子晕存在的结果。中央射电星系MRC 1138-262显示出非常高的全球L CO（4−3）/L CO（1−0）1，这表明除了星星形成的FUV加热机制之外，蜘蛛网星系的中心还存在其他机制。相反，CGM的L CO（4−3）/L CO（1−0）和L [C I]/L CO（1−0）与更宽的原星系团中的5个星系的ISM相似，其碳丰度X[C I]/XH 2与银河系和恒星形成星系相似。分子CGM因此富含金属，不扩散，证实了冷气体和原位星星形成之间的联系。因此，蜘蛛网星系的成长不是直接通过从宇宙网中吸积气体，而是从CGM中回收的气体。
The circumgalactic medium (CGM) of the massive Spiderweb Galaxy, a conglomerate of merging proto-cluster galaxies at z = 2.2, forms an enriched interface where feedback and recycling act on accreted gas. This is shown by observations of [CI], CO(1-0), and CO(4-3) performed with the Atacama Large Millimeter Array and Australia Telescope Compact Array. [CI] and CO(4-3) are detected across ∼50 kpc, following the distribution of previously detected low-surface-brightness CO(1-0) across the CGM. This confirms our previous results on the presence of a cold molecular halo. The central radio galaxy MRC 1138-262 shows a very high global L CO(4−3)/L CO(1−0) ∼ 1, suggesting that mechanisms other than FUVheating by star formation prevail at the heart of the Spiderweb Galaxy. Contrary, the CGM has L CO(4−3)/L CO(1−0) and L [C I]/L CO(1−0) similar to the ISM of five galaxies in the wider proto-cluster, and its carbon abundance, X[C I]/XH2 , resembles that of the Milky Way and star-forming galaxies. The molecular CGM is thus metal-rich and not diffuse, confirming a link between the cold gas and in situ star formation. Thus, the Spiderweb Galaxy grows not directly through accretion of gas from the cosmic web, but from recycled gas in the CGM.