1998A&A...336.1007L

We report the results of a multitransitional study of four southern molecular clouds in the CS J=2-1, J=3-2, J=5-4, J=7-6; CO J=1-0, J=3-2; C³⁴S J=2-1 and C¹⁸O J=1-0 lines observed with SEST and CSO telescopes. To analyze the obtained maps we applied a MEM deconvolution technique which improves the resolution significantly, if the signal-to-noise ratio is sufficiently high. We compare the molecular line maps with available infrared and molecular maser data and for G 268.42-0.85 also with optical DSS image. Two of four cores (G 268.42-0.85 and G 301.12-0.20) show bipolar structure in CS with blue- and red-shifted peaks symmetrically displaced relative the central IR objects. We found that in all observed regions the deconvolved source size decreases sharply with the quantum number of the rotational transition, and the measured FWHP of the CS lines decreases with radius. From optically thin C¹⁸O J=1-0 lines we estimate the H₂ column densities to be of the order of 10²³cm^–2 and from C³⁴S J=2-1 the fractional abundance of CS as 5x10^–9.