Interstellar sulfur isotopes and stellar oxygen burning
| dc.creator | Chin, Y. -N. | |
| dc.creator | Henkel, C. | |
| dc.creator | Whiteoak, J. B. | |
| dc.creator | Langer, N. | |
| dc.creator | Churchwell, E. B. | |
| dc.date | 1995-05-16 | |
| dc.date.accessioned | 2026-07-07T12:41:40Z | |
| dc.date.available | 2026-07-07T12:41:40Z | |
| dc.description | A 12C32S, 13C32S, 12C34S, and 12C33S J = 2 - 1 line survey has been made to study interstellar 32S/34S and 34S/33S ratios from the galactic disk. The four CS isotopomers were detected in 20 star forming regions with galactocentric distances between 3 and 9 kpc. From a comparison of line velocities, the C33S J = 2 - 1 rest frequency is about 250 kHz below the value given in the Lovas (1992) catalog. Taking 12C/13C ratios from Wilson & Rood (1994) and assuming equal 12C32S and 13C32S excitation temperatures and beam filling factors, 12C32S opacities are in the range 3 to 15; average 32S/34S and 34S/33S isotope ratios are 24.4 +/- 5.0 and 6.27 +/- 1.01, respectively. While no systematic variation in the 34S/33S isotope ratio is found, the 32S/34S ratio increases with galactocentric distance when accounting for the 12C/13C gradient of the galactic disk. A fit to the unweighted data yields 32S/34S = 3.3 +/- 0.5 (dGC/kpc) + 4.1 +/- 3.1 with a correlation coefficient of 0.84. Since the interstellar sulfur (S) isotopes are synthesized by oxygen burning in massive stars, consequences for nucleosynthesis and models of chemical evolution are briefly discussed. | |
| dc.description | 11 pages uuencoded gzip-compressed PostScript including two figures, an uncompressed PostScript file with all three figures is also available at http://aibn55.astro.uni-bonn.de:8000/~einmann/cs.html To appear in A&A | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9505067 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9505067 | |
| dc.identifier | Astron.Astrophys.305:960-969,1996 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/219852 | |
| dc.subject | Astrophysics | |
| dc.title | Interstellar sulfur isotopes and stellar oxygen burning | |
| dc.type | text |