The Gas-to-Dust Relation in the Dark Cloud L1523-Observational Evidence for CO Gas Depletion

作     者：H.G.Kim B.G.Kim J.H.Jung 

作者机构：Korea Astronomy and Space Science Institute61-1 Hwaam Yuseong Daejeon 305-348 Korea 

出 版 物：《Chinese Journal of Astronomy and Astrophysics》 (中国天文和天体物理学报（英文版）)

年 卷 期：2008年第8卷第6期

页      面：686-692页

核心收录：

学科分类：0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 070401[理学-天体物理] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 

主　　题：ISM: clouds ISM: dust ISM: molecules 

摘      要：Correlation between gas and dust column density has been studied for the dark globule L1523. The 13CO（J=1→0） emission is used for tracing the gas, and the IR emissions, for tracing the dust constituent. In order to match the beam resolution between the images, a beam de-convolution algorithm based on the Maximum Correlation Method （MCM） was applied on the Infrared Astronomical Satellite （IRAS） data. The morphology of 13CO column density map shows a close correlation to that of 100μm dust optical depth. The distribution of the optical depth at 100 μm follows that of gas column density more closely than does the flux map at either 60 or 100μm. The ratio of the 13CO column density to the 100μm optical depth shows a decreasing trend with increasing dust optical depth in the central part, indicating possible molecular gas condensation onto dust particles. The excessive decrease in the CO column density in the envelope may most probably be due to the photo-dissociation of CO molecules.