SPECTROSCOPY OF THE MOLECULAR ION $CO^{+}$.
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Date
1992
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
The spectra of neutral CO and its ion $CO^{+}$ are of great importance in astrophysical phenomena because both these molecular species are constituents of solar atmosphere, stellar atmospheres, comet tails and interstellar space. Professor Narahari Rao whose research career spans over period of four and half decades has considerable interest on the spectra CO and $CO^{+}$ (see for example Ref. 1--4). The comet-tail $(A^{2}\Pi_{i}$ $- X^{2}\Sigma^{+}$) system of the molecular ion $^{12}C^{16}O^{+}$, excited in the cathode glow of a hollow-cathode discharge tube of special $design^{5}$, was photographed in the spectral region 3400 -- 8500 \AA. Of the seventeen observed bands with $v^{\prime} = 0$ to 8 and $v^{\prime\prime} = 0 to 4$, the rotational structure of twelve bands with $v^{\prime} = 0$ to 4 and 6 and $v^{\prime\prime} = 0$ to 4 was analyzed. An effective Hamiltonian was used to obtain the molecular constants of the individual bands from their wavenumber data and the constants for the A and X states were then determined by merging the molecular constants thus obtained by the method of correlated least-squares $fit^{6}$. Recent experimental data of $^{12}C^{16}O^{+}$ available for the first negative ($B^{2}\Sigma^{+} - X^{2}\Sigma^{+})^{4}$ and the Baldet-Johnson ($B^{2}\Sigma^{+} - A^{2}\Pi_{i}$) systems and for the infrared spectrum involving $v = 0$ and 1, and the microwave spectra involving $v = 0, 1$, and 2, of its ground state X, were reanalyzed using this effective Hamiltonian. Finally a precise set of molecular constants for the X, A, and B states of $^{12}C^{16}O^{+}$ is determined by the procedure referred to above. Recent results obtained on the A-X, B-X and B-A systems of $^{13}C^{18}O^{+}$ in our laboratory will also be discussed.
Description
$^{1,2}$. K.N. Rao, Astrophysical J. 111, 50 (1950), 111, 306 (1950). $^{3}$. K.N. Rao and K.S. Sarma, Mem. Soc. Roy. Sci. Liege Collect. 13, 181 (1953). $^{4}$. P. Misra, D.W. Ferguson, K.N. Rao, E. Williams Jr, and C.W. Mathews, J. Mol. Spectrosc. 125, 54 (1987). $^{5}$. S.P. Reddy and C.V.V. Prasad, J. Phys. Sci. Instrum. 22, 306 (1989). $^{6}$C. Haridass, C.V.V. Prasad, and S.P. Reddy, Astrophysical J., April 1 issue (1992).
Author Institution: Department of Physics, Memorial University of Nfld.
Author Institution: Department of Physics, Memorial University of Nfld.