On the Potential Variation of the Interstellar N/O Ratio

Details On the Potential Variation of the Interstellar N/O Ratio On the Potential Variation of the Interstellar N/O Ratio

Dec 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002aas...201.7711k&link_type=abstract

American Astronomical Society, 201st AAS Meeting, #77.11; Bulletin of the American Astronomical Society, Vol. 34, p.1230

Astronomy and Astrophysics

Astronomy

Scientific paper

To date, all studies of interstellar O I support a constant O/H abundance (e.g., Meyer, Jura, & Cardelli 1998, ApJ, 493, 222). For interstellar N I, the situation is not as well determined. Meyer, Cardelli, & Sofia (1997, ApJ, 490, L103) show a relatively constant N I abundance utilizing seven high-quality GHRS measurements of the weak N I λ 1160 doublet. In striking contrast, factor-of-2 variations in the N I abundance have been detected using high quality IMAPS data (e.g., Jenkins et al. 1999, ApJ, 520, 182; Sonneborn et al. 2000, ApJ, 545, 277). Additionally, recent work (Moos et al. 2002, ApJS, 140, 3 and references therein) shows large scatter when the N/O ratio is considered for 7 lines of sight in the local interstellar medium. Nitrogen is primarily formed during the CNO cycle and expelled into the ISM through the massive winds of Asymptotic Giant Branch (AGB) stars, while O is formed during helium shell burning and returned to the ISM through supernovae. Therefore, the N/O ratio and its possible variation have implications for mixing processes in the interstellar medium (ISM). We present high signal-to-noise (S/N >= 50) Far-Ultraviolet Spectroscopic Explorer (FUSE) observations on the weak interstellar N I λ 1160 doublet toward stars that have existing high quality O I measurements. Our preliminary results when combined with the existing high quality N I and O I data will probe the extent of potential N/O variations. This work is based on data obtained for the Guaranteed Time Team by the NASA-CNES-CSA FUSE mission. Financial support has been provided by NASA contract NAS5-32985.

Affiliated with

Also associated with

No associations

Rating

On the Potential Variation of the Interstellar N/O 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 On the Potential Variation of the Interstellar N/O Ratio, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Potential Variation of the Interstellar N/O Ratio will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1890526