KMS of Xinjiang Astronomical Observatory, CAS
| 银河系内OH脉泽与H2CO的对比研究 | |
| Alternative Title | The Comparison between OH maser and H2COin the Milky Way |
郭伟华
| |
| Subtype | 硕士 |
| Thesis Advisor | 加尔肯·叶生别克 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 天体物理 |
| Keyword | 恒星形成 分子云 甲醛 羟基脉泽 |
| Abstract | 本文对比了18cm OH 脉泽与6cm H2CO(1_10-1_11)吸收线在银河系的分布。大部分OH 脉泽分布在内银河(-75◦ < l < 75◦), 相比H2CO(-5◦ < b < 5◦) 有较高的银纬分布。两分子的速度分布与CO类似，多数源分布在分子环内。在30◦ < l < 90◦ OH脉泽速度分布范围相比H2CO较为弥散。筛选出的OH脉泽与H2CO分子云成协较好，两者速度差小于5km/s。相比16126MHz OH，1665MHz,1667MHzOH脉泽，1720 MHz OH 脉泽在LOH-Lα H2CO 和LOH-Lα IR的关系中指数α较小。小波束望远镜观测的H2CO样本与OH 脉泽有很好的相关性，暗示两分子在激发机制上有相似之处，可能都是由于激波影响。按照OH脉泽类型把样本区分为OH星际脉泽与OH恒星脉泽以及按照是否与红外源成协区分，分别与H2CO的做光度相关性并对比分析，发现OH星际脉泽样本和与红外源成协的样本中两分子的相关性更强，这说明射电连续辐射和红外辐射场在H2CO与OH脉泽的光度关系中起作用。 |
| Other Abstract | We collected 4231 Galactic H2CO absorption lines (~2241 sources) at 6 cm from literatures published to 2014. We compared the distribution of these H2CO absorption lines with OH masers at 18 cm in the Milky Way. Most of OH masers distribute in the inner Galaxy (-75◦ < l < 75◦) with a higher Galactic latitude comparing with H2CO (-5◦ < b < 5◦). The longitude-velocity distributions of H2CO and OH show that the majority of the objects are located in the molecular ring and same as the CO molecular gas does. The range of the velocity of OH maser is larger and diffuser than that of H2CO in the Galactic longitude 30◦ < l < 90◦. We matched H2CO and four ground states of OH and found that OH masers associate well with H2CO clouds with a small velocity deviation (< 5 km s−1). The 1720 MHz OH has a lower power law index(α) in the relation of LOH-LαH2CO and LOH-Lα IR comparing to 1612, 1665, and 1667 MHz OH. H2CO observed by higher resolution telescope is apt to have good correlation with OH maser which implies the two excitation processes have something in common and maybe can attribute to shock effects. The correlation between H2CO and interstellar OH maser is much stronger than that between H2CO and stellar OH maser. The same situation appears in with presence and absent of far infrared radiation(FIR)sources. It indicates the connection between FIR and radio continuum seems to be the bridge that connects OH with H2CO. |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/1713 |
| Collection | 研究生学位论文 射电天文研究室 |
| Affiliation | 中国科学院新疆天文台 |
| Recommended Citation GB/T 7714 | 郭伟华. 银河系内OH脉泽与H2CO的对比研究[D]. 北京. 中国科学院大学,2016. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| 郭伟华-学位论文.pdf（2252KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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