Rovibrational Intensities of the Minor Isotopes of the CO \\ $X\ ^{1} \Sigma^{+}$\ State for $v \leq$\ 20 and $J \leq$\ 150
**Previous
abstract** **Next
abstract**

**Session 112 -- Models and Synthetic Spectroscopy**
*Display presentation, Saturday, January 15, 9:30-6:45, Salons I/II Room (Crystal Gateway)*

## [112.02] Rovibrational Intensities of the Minor Isotopes of the CO \\ $X\ ^{1} \Sigma^{+}$\ State for $v \leq$\ 20 and $J \leq$\ 150

*D. Goorvitch, C. Chackerian, Jr. (NASA/ARC)*
\def\CO#1#2{$^{1#1}$C$^{1#2}$O}

Electric dipole transition matrix
elements for rovibrational transitions in
the ground state $X\ ^{1}
\Sigma^{+}$\ of
the CO minor isotopes \CO46\ and \CO37\
are calculated for the first time for all the $\Delta v$\ = +1, +2, and
+3 transitions for which $v \leq$\ 20 and
$J \leq$\ 150. Improved electric dipole transition matrix
elements are also calculated for the minor isotopes
\CO27, \CO28, and \CO38.
These results for the
minor species of CO complement those previously reported
by us [Goorvitch and Chackerian, ApJS, 1993, *in press*
]
for \CO26\ and \CO36.
We have used the electric dipole moment function (EDMF) from
Chackerian *et al.*
[*Can. J. Phys.*
, **62**
, 1579, 1984]
and the numerical wavefunctions calculated by the method of
Goorvitch and Galant [ *JQSRT*
, **47**
, 391, 1992]
to calculate the rovibrational transition moments.
These calculated transition moments combined with
highly accurate term values and transition frequencies reported
by Farrenq *et al.*
[*J. Molec. Spectrosc.*
, **149**
, 375, 1991]
for \CO27\ and \CO28\ and by Guelachvili *et al.*
[*J. Molec. Spectrosc.*
, **98**
, 64, 1983]
for \CO38, \CO37, and \CO46, or the mass--independent Dunham parameters
of Authier *et al.*
[*J. Molec. Spectrosc.*
, **160**
, 590, 1993]
allow the calculation of the Einstein
A values, $gf$\ values, and the temperature dependent line strengths.
The matrix element of the transition moments are given as a polynomial expansion
in terms of the parameter $m \equiv [J'(J'+1) - J''(J''+1)] / 2$.
The maximum degree for each of the polynomial fits is
derived using orthogonal polynomials which are tested for
statistical significance.
The EDMF used reproduces all the known intensity data on
$X\ ^{1}
\Sigma^{+}$\ CO including the permanent electric moment.
Hure and Roueff [*J. Molec. Spectrosc.*
, **160**
, 335, 1993]
calculated intensities for CO using an *ab initio*
EDMF
which has a permanent moment which is about a factor of
three too large. We have pointed out,
Chackerian and Goorvitch [*J. Molec. Spectrosc.*
, submitted, 1993],
that this discrepancy causes a very large overestimation of the effects of
the vibration--rotation interaction on the calculated intensities.

**Saturday
program listing**