Center-to-limb behavior of first-overtone vibration-rotation transitions of solar carbon monoxide

Journal Article · Sun Oct 15 04:00:00 EDT 1978 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156527· OSTI ID:6799017

Ayres, T R

High-spectral-resolution measurements of the center-to-limb behavior of weak transitions in the carbon monoxide first-overtone (..delta..V=2) vibration-rotation bands (..omega..approx. =4300 cm/sup -1/) are compared with synthetic line widths and equivalent widths for a range of single-component and multicomponent modesl of the solar photosphere. The singel-component thermal structure in best quantitative agreement with the observed properties of the solar CO spectrum is similar to the Vernazza, Avrett, and Loeser model M. Multicomponent models consisting of Gaussian-distributed temperature perturbations around the best-fit model do not significantly affect the computed center-to-limb behavior of CO lines or the solar carbon abundance derived form measured disk-center equivalent widths. The equivalent width ratios of low- and high-excitation lines within a given vibration-rotation band are found to be inconsistent with ''hot'' upper-photosphere models, such as the Linsky and Ayres and Holweger and Mueller semiempirical single-component models, as well as with the two-stream thermal structure proposed by Tsuji. Excitation ratios and center-to-limb behavior of CO lines require a solar carbon abundance near 3 x 10/sup -4/ for an assumed oxygen abundance of 7 x 10/sup -4/. This value is consistent with carbon abundances obtained by Tsuji (CO) and Mount and Linsky (CN), but is much samller than the revised solar carbon abundance recommended recently by Lambert.

• Research Organization: Joint Institute for Laboratory Astrophysics, University of Colorado and National Bureau of Standards
• OSTI ID: 6799017
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 225:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ATMOSPHERES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
LINE WIDTHS
OXIDES
OXYGEN COMPOUNDS
ROTATIONAL STATES
SOLAR ATMOSPHERE
TEMPERATURE DISTRIBUTION
VIBRATIONAL STATES