Astrochemical Properties of Planck Cold Clumps
Astrochemical Properties of Planck Cold Clumps
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DOI：
10.3847/1538-4365/228/2/12
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发表时间：
2016-12
期刊：
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通讯作者：
K. Tatematsu;Tie Liu;S. Ohashi;P. Sanhueza;Q. Nguyen-Luong;T. Hirota;Sheng-Yuan Liu;N. Hirano;Minho Choi;Miju Kang;M. Thompson;G. Fuller;Yue-fang Wu;J. Francesco;Kee-Tae Kim;Ke Wang;I. Ristorcelli;M. Juvela;H. Shinnaga;M. Cunningham;M. Saito;Jeong-Eun Lee;L. V. Tóth;Jinhua He;T. Sakai;Jungha Kim;Jcmt Large ProgramSCOPEcollaboration;Trao Key Science ProgramTOPcollaboration
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文献类型：
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作者：
K. Tatematsu;Tie Liu;S. Ohashi;P. Sanhueza;Q. Nguyen-Luong;T. Hirota;Sheng-Yuan Liu;N. Hirano;Minho Choi;Miju Kang;M. Thompson;G. Fuller;Yue-fang Wu;J. Francesco;Kee-Tae Kim;Ke Wang;I. Ristorcelli;M. Juvela;H. Shinnaga;M. Cunningham;M. Saito;Jeong-Eun Lee;L. V. Tóth;Jinhua He;T. Sakai;Jungha Kim;Jcmt Large ProgramSCOPEcollaboration;Trao Key Science ProgramTOPcollaboration
我们用詹姆斯·克拉克麦克斯韦望远镜/SCUBA-2和野边山45米射电望远镜观测了13个普朗克冷团。用野边山望远镜得到的N2 H+分布与SCUBA-2尘埃分布非常相似。82 GHz HC 3 N、82 GHz CCS和94 GHz CCS发射通常相对于N2 H+发射分布不同。CCS发射，这是众所周知的，是丰富的无星分子云的核心，往往是非常clusive的观测目标。我们在DNC，HN 13 C，N2 D+和环状C3 H2中对9个团块进行了深入的单点观测。N2 D+的检出率为50%。此外，我们还观测了15普朗克冷团的NH3发射，以估计动力学温度，并证实大多数目标是冷的（1020 K）。在我们观察到的两个无星团块中，CCS发射分布在N2 H+核心（化学演化气体）周围，这类似于L1544的情况，一个星前核心显示崩溃。此外，我们检测到DNC和N2 D+。这两个团块极有可能处于星星形成的边缘。我们引入了无星核的化学演化因子（CEF）来描述化学演化阶段，并对观测到的普朗克冷团进行了分析。
We observed 13 Planck cold clumps with the James Clerk Maxwell Telescope/SCUBA-2 and with the Nobeyama 45 m radio telescope. The N2H+ distribution obtained with the Nobeyama telescope is quite similar to SCUBA-2 dust distribution. The 82 GHz HC3N, 82 GHz CCS, and 94 GHz CCS emission are often distributed differently with respect to the N2H+ emission. The CCS emission, which is known to be abundant in starless molecular cloud cores, is often very clumpy in the observed targets. We made deep single-pointing observations in DNC, HN13C, N2D+, and cyclic-C3H2 toward nine clumps. The detection rate of N2D+ is 50%. Furthermore, we observed the NH3 emission toward 15 Planck cold clumps to estimate the kinetic temperature, and confirmed that most targets are cold (≲20 K). In two of the starless clumps we observed, the CCS emission is distributed as it surrounds the N2H+ core (chemically evolved gas), which resembles the case of L1544, a prestellar core showing collapse. In addition, we detected both DNC and N2D+. These two clumps are most likely on the verge of star formation. We introduce the chemical evolution factor (CEF) for starless cores to describe the chemical evolutionary stage, and analyze the observed Planck cold clumps.