observationandstudyofthe13coc18ohcoandn2hmolecularlinestowardsiras022326138

	observationandstudyofthe13coc18ohcoandn2hmolecularlinestowardsiras022326138
	Liubin Zhu; Ji Yang; Min Wang
刊名	chineseastronomyandastrophysics
	2007
卷号	31 期号:4 页码:387
ISSN号	0275-1062
英文摘要	Using the 13.7 m millimeter-wave telescope at the Qinghai Station of Purple Mountain Observatory, we have made observations of 13 CO, C 18 O, HCO + and N 2 H + molecular lines towards IRAS 02232+6138. As the excitation density of the probe molecule increases from 13 CO to HCO + , the size of the cloud core associated with IRAS 02232+6138 decreases from 2.40 pc to 0.54 pc, and the virial mass of the cloud core decreases from 2.2 × 10 3 M ⊙ to 5.1 × 10 2 M ⊙ . A bipolar molecular outflow is found towards IRAS 02232+6138. Using the power function n ( r ) ∝ r ?α to fit the spatial density structure of the cloud core, we obtain the power-law index α = 2.3 ? 1.2; and we find that, as the probed density increases, the power function becomes more flat. The abundance ratio of 13 CO to C 18 O is 12.4 ± 6.9, comparable with the values 11.8 ± 5.9 for dark clouds and the values 9.0–15.6 for massive cores. The abundance of N 2 H + molecules is 3.5 ± 2.5 × 10 ?10 , consistent with the value 1.0 ? 5.0 × 10 ?10 for dark cloud cores and the value 1.2 ? 12.8 × 10 ?10 for massive cores. The abundance of HCO + molecules is 0.9 ± 0.5 × 10 ?9 , close to the value 1.6 ? 2.4 × 10 ?9 for massive cores. An increase of HCO + abundance in the outflow region was not found. Combining with the IRAS data, the luminosity-mass ratio of the cloud core is obtained in the range 37–163( L M ) ⊙ . Based on the IRAS luminosity, it is estimated that a main-sequence O7.5 star is probably embedded in the IRAS 02232+6138 cloud core.
语种	英语
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/31835]
专题	中国科学院紫金山天文台
作者单位	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Liubin Zhu,Ji Yang,Min Wang. observationandstudyofthe13coc18ohcoandn2hmolecularlinestowardsiras022326138[J]. chineseastronomyandastrophysics,2007,31(4):387.
APA	Liubin Zhu,Ji Yang,&Min Wang.(2007).observationandstudyofthe13coc18ohcoandn2hmolecularlinestowardsiras022326138.chineseastronomyandastrophysics,31(4),387.
MLA	Liubin Zhu,et al."observationandstudyofthe13coc18ohcoandn2hmolecularlinestowardsiras022326138".chineseastronomyandastrophysics 31.4(2007):387.