典型文献
Chemical Evolution During the Formation of Molecular Clouds
文献摘要：
To study the chemical evolution during the formation of molecular clouds, we model three types of clouds with different density structures:collapsing spherical, collapsing ellipsoidal, and static spherical profiles. The collapsing models are better than the static models in matching the observational characteristics in typical molecular clouds. This is mainly because the gravity can speed up the formation of some important molecules (e.g., H2, CO, OH) by increasing the number density during collapse. The different morphologies of prolate, oblate, and spherical clouds lead to differences in chemical evolution, which are mainly due to their different evolution of number density. We also study the effect of initial chemical compositions on chemical evolution, and find that H atoms can accelerate OH formation by two major reactions:O+H→OH in gas phase and on dust grain surfaces, leading to the models in which hydrogen is mainly atomic initially better match observations than the models in which hydrogen is mainly molecular initially. Namely, to match observations, initially hydrogen must be mostly atomic. The CO molecules are able to form even without the pre-existence of H2. We also study the influence of gas temperature, dust temperature, intensity of interstellar radiation field and cosmic-ray ionization rate on chemical evolution in static clouds. The static CO clouds with high dust temperature, strong radiation field, and intensive cosmic rays are transient due to rapid CO destruction.
文献关键词：
中图分类号：
作者姓名：
Jingfei Sun;Fujun Du
作者机构：
Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026,China
文献出处：
引用格式：
[1]Jingfei Sun;Fujun Du-.Chemical Evolution During the Formation of Molecular Clouds)[J].天文和天体物理学研究,2022(06):269-290
A类：
B类：
Chemical,Evolution,During,Formation,Molecular,Clouds,To,study,chemical,evolution,during,formation,molecular,clouds,we,three,types,different,density,structures,collapsing,spherical,ellipsoidal,static,profiles,models,are,better,than,matching,observational,characteristics,typical,This,mainly,because,gravity,can,speed,up,some,important,molecules,H2,by,increasing,number,collapse,morphologies,prolate,oblate,differences,which,due,their,We,also,effect,compositions,find,that,atoms,accelerate,two,major,reactions,O+H,gas,phase,dust,grain,surfaces,leading,hydrogen,atomic,initially,observations,Namely,must,mostly,able,even,without,pre,existence,influence,temperature,intensity,interstellar,radiation,field,cosmic,ionization,high,strong,intensive,rays,transient,rapid,destruction
AB值：
0.500336
相似文献
机标中图分类号，由域田数据科技根据网络公开资料自动分析生成，仅供学习研究参考。
