Table 4: Selection rules for the ro-vibration transitions in addition to $\Delta J = 0,\ \pm 1$ . The transitions in brackets are weaker than the main transitions. For ro-vibrational transitions, the parity of K_a+K_c+v₃ has to be conserved. Transitions of type a only occur for oblate molecules, whereas transitions of type c are only found for prolate molecules. Both oblate and prolate molecules can have b-type transitions.
Transition Criterion $\Delta K_{{a}}$ $\Delta K_{{c}}$

a-type $\mu_a \neq 0$ $0, \pm 2\ (\pm 4,\ ...)$ $\pm 1\ (\pm 3,\pm 5,\ ...)$

b-type $\mu_b \neq 0$ $\pm 1, \pm 3\ ( \pm 5,\ ...)$ $\pm 1, \pm 3\ ( \pm 5,\ ...)$

c-type $\mu_c \neq 0$ $\pm 1\ (\pm 3,\pm 5,\ ...)$ $0, \pm 2\ (\pm 4,\ ...)$

**Table 4:** Selection rules for the ro-vibration transitions in addition to $\Delta J = 0,\ \pm 1$ . The transitions in brackets are weaker than the main transitions. For ro-vibrational transitions, the parity of K_a+K_c+v₃ has to be conserved. Transitions of type a only occur for oblate molecules, whereas transitions of type c are only found for prolate molecules. Both oblate and prolate molecules can have b-type transitions.
Transition	Criterion	$\Delta K_{{a}}$	$\Delta K_{{c}}$
a-type	$\mu_a \neq 0$	$0, \pm 2\ (\pm 4,\ ...)$	$\pm 1\ (\pm 3,\pm 5,\ ...)$
b-type	$\mu_b \neq 0$	$\pm 1, \pm 3\ ( \pm 5,\ ...)$	$\pm 1, \pm 3\ ( \pm 5,\ ...)$
c-type	$\mu_c \neq 0$	$\pm 1\ (\pm 3,\pm 5,\ ...)$	$0, \pm 2\ (\pm 4,\ ...)$

Source LaTeX | All tables | In the text

	1 Introduction
	2 Observations
	3 Chemical modeling
	4 Results of the chemical model calculations and discussion
	5 Conclusion and future prospects
	References