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

• Published in: Chinese journal of astronomy and astrophysics Vol. 8; no. 6; pp. 686 - 692
• Main Authors: Kim, H. G, Kim, B. G, Jung, J. H
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2008
• ISSN: 1009-9271
• DOI: 10.1088/1009-9271/8/6/07

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 100 is a subset of m dust optical depth. The distribution of the optical depth at 100 is a subset of m follows that of gas column density more closely than does the flux map at either 60 or 100 is a subset of m. The ratio of the 13CO column density to the 100 is a subset of m 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.