13CI in high-mass star-forming clouds

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

4 pages, 2 figures, submitted to A&A Letters

Scientific paper

10.1051/0004-6361:20010939

We report measurements of the 12C/13C abundance ratio in the three galactic regions G 333.0-0.4, NGC 6334 A and G 351.6-1.3 from observations of the 12CI 3P2-3P1 transition and the hyperfine components of the corresponding 13CI transition near 809 GHz. These transitions were observed simultaneously with the CO 7-6 line emission at 806 GHz with the AST/RO telescope located at the South Pole. From a simultaneous fit to the 12CI 3P2-3P1 transition and the HF components of the corresponding 13CI transition and an independent estimate of an upper limit to the optical depth of the 12CI emission we determine intrinsic 12CI/13CI column density ratios of 23+-1 for G 333.0-0.4, 56+-14 for NGC 6334 A and 69+-12 for G 351.6-1.3. As the regions observed are photon dominated, we argue that the apparent enhancement in the abundance of 13C towards G 333.0-0.4 may be due to strong isotope-selective photodissociation of 13CO, outweighing the effects of chemical isotopic fractionation as suggested by models of PDRs. Towards NGC 6334 A and G 351.6-1.3 these effects appear to be balanced, similar to the situation for the Orion Bar region observed by Keene et al. (1998).

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

13CI in high-mass star-forming clouds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with 13CI in high-mass star-forming clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 13CI in high-mass star-forming clouds will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-244687

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.