Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. IV. The ALMA view of N113 and N159W in the LMC
Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. IV. The ALMA view of N113 and N159W in the LMC
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用甲醛测量的大量恒星形成分子团的动力学温度。
DOI：
10.1051/0004-6361/202141804
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发表时间：
2016-10
影响因子：
6.5
通讯作者：
He Y
中科院分区：
文献类型：
--
作者：
Tang X. D.;Henkel C.;Menten K. M.;Gong Y.;Chen C. -H. R.;Li D. L.;Lee M. -Y.;Mangum J. G.;Ao Y. P.;Muhle S.;Aalto S.;Garcia-Burillo S.;Martin S.;Viti S.;Muller S.;Costagliola F.;Asiri H.;Levshakov S. A.;Spaans M.;Ott J.;Impellizzeri C. M. V.;Fukui Y.;He Y
为了对星星形成过程中的物理学有一个总体的了解，测量温度和密度等物理参数是必不可少的。分子云密集团块的化学和物理性质受动力学温度的强烈影响。因此，这个参数对于更好地理解星际介质至关重要。甲醛是一种示踪整个致密分子气体的分子，是直接测量气体动力学温度最可靠的示踪剂。我们的目标是用甲醛的谱线确定气体动力学温度，并与大量块状团簇的氨谱线结果进行比较。三个218 GHz的跃迁在高质量星星形成的不同阶段，用15米詹姆斯·克拉克麦克斯韦望远镜（JCMT）对30个大质量星系团观测到了对位H2 CO（JKAKC=303-202，322-221和321-220）。使用RADEX非LTE模型，我们推导出气体动力学温度模拟测量的para-H2 CO 322-221/303- 202和321-220/303-202的比例。由对-H_2CO（321-220/303-202）线比值导出的气体动力学温度范围为30 ~ 61 K，平均为46 K。动力学温度的比较，从para-H2 CO，NH3，和灰尘排放表明，在许多情况下，para-H2 CO跟踪类似的动力学温度NH3（2，2）/（1，1）的转变和灰尘与HII地区。明显更高的温度探测与外流/冲击相关的团块中的对位H2 CO。动力学温度从para-H2 CO示踪湍流获得的大规模团块中的NH3（2，2）/（1，1）的程度高于。对-H_2CO谱线的非热速度色散与气体动力学温度呈正相关。大质量的团块显着影响超音速非热运动。
For a general understanding of the physics involved in the star formation process, measurements of physical parameters such as temperature and density are indispensable. The chemical and physical properties of dense clumps of molecular clouds are strongly affected by the kinetic temperature. Therefore, this parameter is essential for a better understanding of the interstellar medium. Formaldehyde, a molecule which traces the entire dense molecular gas, appears to be the most reliable tracer to directly measure the gas kinetic temperature.We aim to determine the kinetic temperature with spectral lines from formaldehyde and to compare the results with those obtained from ammonia lines for a large number of massive clumps.Three 218 GHz transitions (JKAKC=303-202, 322-221, and 321-220) of para-H2CO were observed with the 15m James Clerk Maxwell Telescope (JCMT) toward 30 massive clumps of the Galactic disk at various stages of high-mass star formation. Using the RADEX non-LTE model, we derive the gas kinetic temperature modeling the measured para-H2CO 322-221/303-202and 321-220/303-202 ratios. The gas kinetic temperatures derived from the para-H2CO (321-220/303-202) line ratios range from 30 to 61 K with an average of 46 K. A comparison of kinetic temperature derived from para-H2CO, NH3, and the dust emission indicates that in many cases para-H2CO traces a similar kinetic temperature to the NH3 (2,2)/(1,1) transitions and the dust associated with the HII regions. Distinctly higher temperatures are probed by para-H2CO in the clumps associated with outflows/shocks. Kinetic temperatures obtained from para-H2CO trace turbulence to a higher degree than NH3 (2,2)/(1,1) in the massive clumps. The non-thermal velocity dispersions of para-H2CO lines are positively correlated with the gas kinetic temperature. The massive clumps are significantly influenced by supersonic non-thermal motions.
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DOI：
10.1088/0004-637x/785/1/55
发表时间：
2014-02
期刊：
The Astrophysical Journal
影响因子：
--
作者：
J. Ott;A. Weiss;L. Staveley-Smith;C. Henkel;D. Meier
通讯作者：
J. Ott;A. Weiss;L. Staveley-Smith;C. Henkel;D. Meier
DOI：
10.1088/0004-637x/743/1/56
发表时间：
2011-09
期刊：
The Astrophysical Journal
影响因子：
--
作者：
C. Cyganowski;C. Brogan;T. Hunter;E. Churchwell
通讯作者：
C. Cyganowski;C. Brogan;T. Hunter;E. Churchwell
DOI：
10.1088/0004-637x/766/2/108
发表时间：
2013-02
期刊：
The Astrophysical Journal
影响因子：
--
作者：
J. Mangum;J. Darling;C. Henkel;K. Menten
通讯作者：
J. Mangum;J. Darling;C. Henkel;K. Menten
DOI：
10.1086/171167
发表时间：
1992-04
期刊：
The Astrophysical Journal
影响因子：
--
作者：
J. Mangum;A. Wootten;L. Mundy
通讯作者：
J. Mangum;A. Wootten;L. Mundy
影响因子：
6.5
作者：
S. Treviño-Morales;P. Pilleri;A. Fuente;C. Kramer;È. Roueff;M. Gonz'alez-Garc'ia;J. Cernicharo;M. Gerin;J. Goicoechea;J. Pety;O. Bern'e;V. Ossenkopf;D. Ginard;S. Garc'ia-Burillo;J. Rizzo;S. Viti
通讯作者：
S. Treviño-Morales;P. Pilleri;A. Fuente;C. Kramer;È. Roueff;M. Gonz'alez-Garc'ia;J. Cernicharo;M. Gerin;J. Goicoechea;J. Pety;O. Bern'e;V. Ossenkopf;D. Ginard;S. Garc'ia-Burillo;J. Rizzo;S. Viti