Abstract
To use a molecule as a diagnostic of a single star forming region, one has to observe it in different transitions. That is especially true for galaxies, where the beam filling factor is small and unknown. From studies of Galactic objects, the CS molecule is a good tracer of dense gas. Toward the IR galaxies NGC 253, IC 342 and M 82, Mauersberger and Henkel (1989) observed the J=2—1, 3=—2 and 5—4 transitions of CS at 3, 2 and 1.3 mm wavelength, repectively. They also measured emission of the isotope C34S, which has an abundance ~ 1/23 that of the main isotope. This study revealed that the H2 densities in the circumnuclear gas exceed 104, and, in the case of NGC 253, 105 cm-3. In all three cases, the distribution of the dense gas traced out by CS follows the CO distribution
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
