Molecular Gas Excitation of the Massive Dusty Starburst CRLE and the Main-sequence Galaxy HZ10 at z = 5.7 in the COSMOS Field
Molecular Gas Excitation of the Massive Dusty Starburst CRLE and the Main-sequence Galaxy HZ10 at z = 5.7 in the COSMOS Field
复制标题
DOI：
10.3847/1538-4357/ac403a
复制
发表时间：
2021-12
期刊：
影响因子：
--
通讯作者：
Daniel Vieira;D. Riechers;R. Pavesi;A. Faisst;E. Schinnerer;N. Scoville;G. Stacey
中科院分区：
文献类型：
--
作者：
Daniel Vieira;D. Riechers;R. Pavesi;A. Faisst;E. Schinnerer;N. Scoville;G. Stacey
本文报道了用北方扩展毫米波阵列对星爆星系CRLE （z = 5.667）和主序星系HZ10 （z = 5.654）的CO（5→4）线和CO（6→5）线的观测结果。CRLE是宇宙场中最明亮的z > 5星暴，而HZ10是目前已知的z > 5中气体最丰富的“正常”星系。我们发现CO（5→4）和CO（6→5）的线光度分别为（4.9±0.5）和（3.8±0.4）× 1010 K km s−1 pc2，这是CRLE和5个尘埃恒星形成星系的上限。对于HZ10来说，这些光度线限制为zbbbb50的MS星系提供了第一个重要的限制。我们发现HZ10的L5→4’/L2→1’的上限可能与MS星系在z≈1.5附近的平均值相似，这表明具有类似气体激发的MS星系可能在大爆炸后10亿年就已经存在了。对于CRLE，我们根据CO线梯的激发模型确定H2密度、动力学温度和粉尘温度的最可能值。我们还推导出总气体质量为（7.1±1.3）× 1010 M⊙。我们的发现提供了一些目前最详细的关于气体激发的限制，这些气体激发设定了z bbb50星系原星团环境中恒星形成的条件。
We report CO(5 → 4) and CO(6 → 5) line observations in the dusty starbursting galaxy CRLE (z = 5.667) and the main-sequence (MS) galaxy HZ10 (z = 5.654) with the Northern Extended Millimeter Array. CRLE is the most luminous z > 5 starburst in the COSMOS field and HZ10 is the most gas-rich “normal” galaxy currently known at z > 5. We find line luminosities for CO(5 → 4) and CO(6 → 5) of (4.9 ± 0.5) and (3.8 ± 0.4) × 1010 K km s−1 pc2 for CRLE and upper limits of 5 dusty star-forming galaxies. For HZ10, these line luminosity limits provide the first significant constraints of this kind for an MS galaxy at z > 5. We find the upper limit of L5→4′/L2→1′ in HZ10 could be similar to the average value for MS galaxies around z ≈ 1.5, suggesting that MS galaxies with comparable gas excitation may already have existed one billion years after the Big Bang. For CRLE we determine the most likely values for the H2 density, kinetic temperature, and dust temperature based on excitation modeling of the CO line ladder. We also derive a total gas mass of (7.1 ± 1.3) × 1010 M ⊙. Our findings provide some of the currently most detailed constraints on the gas excitation that sets the conditions for star formation in a galaxy protocluster environment at z > 5.