Astronomy and Astrophysics – Astronomy
Scientific paper
Feb 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994pasj...46...53t&link_type=abstract
PASJ: Publications of the Astronomical Society of Japan (ISSN 0004-6264), vol. 46, no. 1, p. 53-72
Astronomy and Astrophysics
Astronomy
59
Abundance, Carbon, Dwarf Stars, Infrared Spectra, Light (Visible Radiation), Line Spectra, Local Thermodynamic Equilibrium, Nitrogen, Oxygen, Photosphere, Astronomical Spectroscopy, Collision Rates, Infrared Astronomy, Mathematical Models, Metallicity, Statistical Analysis, Turbulence
Scientific paper
Statistical equilibrium calculations with realistic atomic models of C, N, and O were performed to clarify how the non-local thermodynamic equilibrium (non-LTE) effect plays a role in determining the photospheric CNO abundances (from lines of neutral atoms in the optical/IR region) for the Sun and Procyon. In addition, it was also examined to which amount the derived abundances are affected by a change in the collisional rates/microturbulence/damping parameter/model atmosphere, as well as by the molecule formation effect. The resulting non-LTE abundance corrections (absolute value of delta log epsilon) turned out to be less than or approximately equal to 0.2 dex for most of the lines for both stars, which are regarded as being not very significant and being more or less comparable to the uncertainties involved in the several factors mentioned above. The CNO abundances of Procyon were confirmed to be practically the same as the solar compositions. Special attention was paid to the oxygen triplett lambda 7771-5, which was found to show only an insignificant amount of the non-LTE effect by absolute value of delta log epsilon approximately equal to 0.06 for the Sun (being less than those previously reported by other investigators), though an appreciably large correction of approximately 0.4 dex was derived for Procyon. A reasonable interpretation was found for the observed center to limb variation of the strength of this triplet in the Sun. Furthermore, it was revealed that the controversial problem regarding the well-known discrepancy between the oxygen abundances derived from the lambda 7771-5 and lambda 6300 lines in population II F-G dwarfs is satisfactorily explained by the non-LTE effect predicted by the present calculations.
No associations
LandOfFree
Non-LTE effect on CNO abundance determinations for solar-type stars: The Sun, Procyon, and the oxygen problem in metal-poor dwarfs 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 Non-LTE effect on CNO abundance determinations for solar-type stars: The Sun, Procyon, and the oxygen problem in metal-poor dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-LTE effect on CNO abundance determinations for solar-type stars: The Sun, Procyon, and the oxygen problem in metal-poor dwarfs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1018811