High mass-loss carbon stars and the evolution of the local ^12^C/^13^C ratio.

Details High mass-loss carbon stars and the evolution of the local ^12^C/^13^C ratio. High mass-loss carbon stars and the evolution of the local ^12^C/^13^C ratio.

Nov 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997a%26a...327..342g&link_type=abstract

Astronomy and Astrophysics, v.327, p.342-348

Astronomy and Astrophysics

Astrophysics

15

Ism: Abundances, Ism: Clouds

Scientific paper

The ^12^C/^13^C ratio has been measured in a sample of 10 carbon stars with high mass-loss rates, of >=10^-5^Msun_/yr. This sample is complete for northern hemisphere carbon stars within ~1kpc of the Sun. Using the J=2-1 rotational lines of CO and ^13^CO, the intensity ratio of ^12^CO/^13^CO is found to be 17+/-11 for the sample, and the deduced ^12^C/^13^C abundance ratio, after corrections for CO optical depth effects, is 25+/-13. The isotopic ratios are rather uniform (12-36 for 9 of the 10 stars), and there are no stars with very low ^12^C/^13^C values, such as the ratios of 3-4 found for a few low mass-loss carbon stars. The ejecta from the high mass-loss objects will dominate the evolution of the ^12^C/^13^C ratio in the local interstellar medium, since mass return is dominated by AGB stars, and the stars of the highest ˙(M) return the majority of the carbon. Thus the ejection of ^13^C-rich material from AGB stars could explain the evolution of the local ^12^C/^13^C ratio from 89 at the time of the Sun's formation, to 60-70 now. From our data, it is estimated that the local ISM ratio should have evolved to =~72+/-8 at the present time, which agrees with ISM observations. The AGB stars can therefore fully explain the enrichment of the local ISM in ^13^C.

Affiliated with

Also associated with

No associations

Rating

High mass-loss carbon stars and the evolution of the local ^12^C/^13^C ratio. 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 High mass-loss carbon stars and the evolution of the local ^12^C/^13^C ratio., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High mass-loss carbon stars and the evolution of the local ^12^C/^13^C ratio. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1682438