Analytic representations of rovibrational dipole matrix elements for the CO molecule and its isotopomers

Abstract

Abstract. -We report new calculations of transition matrix elements for more than thirty thousand infrared lines of the CO molecule and its isotopomers inside the X 1 Σ + ground electronic state. These lines belong to the ∆v=1, 2, 3 bands involving very high excited states such as v ≤41 and J ≤133. The transition matrix elements have been calculated from an accurate solution of the Schrödinger equation by using two different theoretical electric dipole moment functions (Werner 1981;Langhoff & Bauschlicher 1995). For low lying levels, our data compare satisfactorily with experimental ones and related works (Goorvitch & Chackerian 1994a, b;Chackerian et al. 1994, Goorvitch 1994. Moreover, we make predictions for oscillator strengths and Einstein coefficients involving high excited transitions. In addition, we report simple analytic formulae that fit our results for 12 C 16 O with an accuracy better than 10 −2 as a function of m = [J (J + 1) − J (J + 1)]/2 for each vibrational sequence and band. They offer an easy way to compute the various intensities of these rovibrational transitions whose transition energies may be introduced via the available Dunham coefficients.

Solar Carbon Monoxide, Thermal Profiling, and the Abundances of C, O, and Their Isotopes

“…In columns 9 and 10, the uncertainties are the 1 σ dispersions in each 40-member abundance sample, with no filtering and not accounting for a possible correlation between ǫ O and E lower . Goorvitch (1994) was used as reference, and relative behavior of Hure & Roueff (1996) gf -values are depicted as darker (red) dots (∆v = 1) and open circles (∆v = 2) in upper part of diagram. Specific points refer to CO abundance sample described in text: 40 lines from fundamental, 40 from first overtone.…”

“…In second panel, small squares depict fraction of oxygen bound in CO: n CO /(ǫ O n H ). In T min region, ratio is nearly 0.5 reflecting that virtually all available carbon (C/O= 0.5) has been captured into CO. Goorvitch (1994) and Hure & Roueff (1996). Panels to left are "cartoons" of particular models used in the simulations; FAL C temperature distribution is provided (as a thin curve) in each panel for comparison.…”

“…Curiously, agreement between ∆v = 1 and 2 abundances is improved: this contrast is temperature sensitive in principle because one is comparing generally low excitation ∆v = 2 lines to mainly high excitation ∆v = 1 transitions, although one also must be wary of systematic errors in line absorption strengths which potentially could mimic a temperature effect, as seen in Fig. 8 for Hure & Roueff (1996) Asplund et al (2004), and removes excitation gradient between fundamental and first overtone samples, but low-T model completely fails continuum center-limb test, like Asplund model itself.…”

ROVIBRATIONAL LINE LISTS FOR NINE ISOTOPOLOGUES OF THE CO MOLECULE IN THE X 1 Σ + GROUND ELECTRONIC STATE

“…In the literature, there are two rovibrational line lists most frequently used involving high v and J quantum numbers for the CO molecule for astrophysical applications (Goorvitch 1994;Hure & Roueff 1996). However, significant differences have been found between the reported line intensities of the two data sets.…”

CO isotopologue ratios in the solar photosphere

“…In order to determine isotopologue abundances from the observations, the f-values (oscillator strengths) are needed for the rovibrational transitions of the ground electronic state of different isotopic C x O for x=16, 17, 18. The two most commonly used oscillator 308 J. R. Lyons, E. Gharib-Nezhad & T. R. Ayres strength scales are Hure & Roueff (1996) and Goorvitch (1994)(HR96 and G94, respectively). For a given rovibrational transition the f-value is proportional to the square of rovibrational dipole moment.…”