Theoretical Molecular Line Absorption of CO in Late Spectral Type Atmospheres.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Theoretical Molecular Line Absorption of CO in Late Spectral Type Atmospheres. Kunde, Virgil G. Abstract The line positions, line intensities and collisional line half- widths have been calculated for the fundamental, first overtone, and second overtone vibration-rotation bands of `2C'60 and `3C'60. The l2CioO and 13C'60 line intensities were computed for temperature ranging from 1 75-35000K and were weighted in accordance with a terrestrial 12C/'3C abundance ratio. All lines within 5-6 orders of magnitude of the maximum line intensity of a band have been considered (~4500 lines at 35000K). Tables of the above molecular absorption line parameters are being published (Kunde, XASA Document X-622- 67-248, June 1967). The CO mass absorption coefficient has been computed for several typical late spectral type stellar atmosphere conditions. The straight mean absorption coefficient has been evaluated for these conditions in several ways: (1) line-by-line integration technique, (2) quasi-random band model, and (3) S~rn/Ap approximation, where STm is the total line intensity in spectral interval Av. The results indicate the simpler STrn/AP model represents the CO mean absorption coefficient in the late-type atmospheres generally to an accuracy better than 1 % if the spectral intervals are greater than 5 cm-'. For regions short of 1609 cm~', the accuracy of the S~m/Ap model is 5-10%. The quoted accuracies are based on the fundamental band for T= 25000K, pressures up to 2 atm and turbulent velocities up to 10 km/sec. The mean absorption coefficient S~m/Ap has been determined for CO for temperatures of 10000, 25000, and 35000K. Publication: The Astronomical Journal Pub Date: 1967 DOI: 10.1086/110449 Bibcode: 1967AJ.....72Q.810K full text sources ADS |