Radiation-driven implosion in the Cepheus B molecular cloud  

作　　者：Sheng Chen Maohai Huang 

机构地区：[1]National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Research in Astronomy and Astrophysics》2010年第8期777-784,共8页天文和天体物理学研究（英文版）

摘　　要：We analyze large scale mapping observations of the molecular lines in the ^12CO（J= 2-1）,^12CO（J=3-2）,^13CO（J=2-1）,and ^13CO（J=3-2） transition emissions toward the Cepheus B molecular cloud with the KOSMA 3mtelescope. The integrated intensity map of the ^12CO （J = 2 - 1） transition has shown a structure with a compact core and a compact ridge extended to the north-west of the core. The cloud is surrounded by an optically bright rim, where the radiation-driven implosion （RDI） may greatly change the gas properties. The intensities of the CO （J = 3 - 2） transition are higher than those of the CO （J = 2 - 1） transition along the rim area. We find characteristic RDI structure in position-velocity diagrams. Non-LTE large velocity gradient （LVG） model analysis shows that the density and temperature at the edge are higher than that in the center. Our results provide evidences that an RDI is taking place in the Cepheus B molecular cloud.We analyze large scale mapping observations of the molecular lines in the ^12CO（J= 2-1）,^12CO（J=3-2）,^13CO（J=2-1）,and ^13CO（J=3-2） transition emissions toward the Cepheus B molecular cloud with the KOSMA 3mtelescope. The integrated intensity map of the ^12CO （J = 2 - 1） transition has shown a structure with a compact core and a compact ridge extended to the north-west of the core. The cloud is surrounded by an optically bright rim, where the radiation-driven implosion （RDI） may greatly change the gas properties. The intensities of the CO （J = 3 - 2） transition are higher than those of the CO （J = 2 - 1） transition along the rim area. We find characteristic RDI structure in position-velocity diagrams. Non-LTE large velocity gradient （LVG） model analysis shows that the density and temperature at the edge are higher than that in the center. Our results provide evidences that an RDI is taking place in the Cepheus B molecular cloud.

关 键 词：submillimeter -- ISM clouds -- ISM globules -- stars FORMATION 

分 类 号：P155.22[天文地球—天文学] TL613[核科学技术—核技术及应用]