Knowledge Bank

The absorption spectrum of nitrogen has been investigated with a 6.65m vacuum spectrograph. The rotational analyses of the bands invalved, with $e4(O)$ and $c5\prime (O)$ upper states, were reported here in 1981. Recent results for the $c4(O)$ - and $c5\prime (O)-a""(O)$ bands obtained by high resolution optogalvanic $techniques(1)$ are compared with those from the VUV absorption bands. The rotational assignments of the VUV and the visible bands involving $c5\prime (O)$ and $c4(O)+$ levels have been confirmed. However, the J-assignments of the $c4(O)-$ levels have been revised and are now consistent with the combined data from the VUV and visible bands. The absolute term values and rotational constants of a""(O) level are also deduced from the combined data. The interaction between the Rydberg and non-Rydberg levels will be discussed in connection with a newly assigned $c4(O)\Pi -$ level.